How do mushrooms, which are a fungus, reproduce? what is artificial selection? What is wind pollination?

UNIVERSITY OF LOUISIANA AT LAFAYETTE / Biology / BIOL 122 / How do mushrooms, which are a fungus, reproduce?

How do mushrooms, which are a fungus, reproduce?

How do mushrooms, which are a fungus, reproduce?
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School: University of Louisiana at Lafayette

Department: Biology

Course: Biology Principle & Issues II

Term: Fall 2019

Tags: Biology, #bio122, Science, and Exam 1

Cost: 50

Name: BIO 122 Exam 1 Study Guide

Description: These notes cover what is going to be on Exam 1! The topics are Fungi & Plant Evolution, Plant Anatomy, Plant Nutrition & Transport, Plant Reproduction, Plant Hormones, Animal Diversity, and Animal Structure & Temperature Regulation.

Uploaded: 09/18/2019

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Biology 122

How do mushrooms, which are a fungus, reproduce?

9-23-19

Exam 1 Study Guide

This exam covers these PowerPoint topics from weeks 1-4: - Fungi & Plant Evolution

- Plant Anatomy

- Plant Nutrition & Transport

- Plant Reproduction

- Plant Hormones

- Animal Diversity

- Animal Structure & Temperature Regulation

- Fungi & Plant Evolution

o Fungi:

 Fungal bodies consist of fine threads.

 Cells produce cell walls made of chitin.

 Chitin- a polymer of amino glucose.

 Fungi are heterotrophs.

what is artificial selection?

 Heterotrophs- they obtain energy and nutrients

from other organisms.

 Their digestion is extracellular.

 Reproduction can be asexual or sexual.

 Humans eat some fungi (certain mushrooms).

 Many produce antibiotics/other drugs.

 Some damage crop plants and stored food.

 Some infect our bodies and are poisonous.

 We use some of them to make bread and fermented

beverages (beer).

o Major Groups of Fungi:

 Chytridiomycota (aquatic).

 Neocallimastigomycota (anaerobic; produce cellulase).  Blastocladiomycota (aquatic decomposers).

 Glomeromycota (mycorrhizae).

 Basidiomycota (club fungi).

What is wind pollination?

 Ascomycota (sac fungi).

- How do mushrooms, which are a fungus, reproduce?

o A.) only asexually

o B.) only sexually

o C.) between sexual & asexual reproduction

o D.) through cloningWe also discuss several other topics like soc 310 purdue

o Evolution of Plants: If you want to learn more check out an mis infrastructure is dynamic and static

 Land plants evolved from freshwater algae.

 There are 4 major groups of land plants.

 Brynophytes (mosses).

o Ex: Liverwort, Hornwort, Moss, & Sphagnum

bog.

o Mosses: no seeds & no vascular tissue.

o Gametophyte is dominant.

 Pteridophytes (ferns).

o Ex: Club mosses, Horsetails, & ferns.

o No seeds but have vascular tissue.

o Sporophyte is dominant. If you want to learn more check out lsu poli

 Gymnosperms (conifers).

o Ex: Gingko, Cycad, & Conifer.

o Produce seeds, but no flowers.

 Angiosperms (flowering plants).

o Ex: Duckweed, Eucalyptus, & Grass.

o Produce seeds & have flowers.

 All plants have 2 life stages.

 Sporophyte (haploid).

 Gametophyte (diploid).

- Plant Anatomy

o Main Parts:

 Shoot- the part of the plant above the ground.

 Root- the part of the plant underneath the ground.

o Plant Tissues:

 Primary growth = means that length increases.

 A.) Meristems

 B.) Simple (mostly one cell type)

 1.) Parenchyma

o Photosynthesis, storage of starch and oils,

etc.

 2.) Collenchyma

o Support; cell walls contain pectin.

 3.) Sclerenchyma

o No cytoplasm; cell walls contain lignin.

 C.) Complex (several cell types)

 4.) Dermal

 5.) Vascular

 6.) Ground

o Stems: Morphological Plasticity

 Morphological plasticity = all different. We also discuss several other topics like emch 210

 Ex: Stolons, Rhizomes, Bulbs, Corms, Tubers, &

Clacodes.

o Leaf Structure:

 Leaves also have morphological plasticity.

 Ex: elliptic, palmate, lobed, pinnatisect, acuminate odd pinnate, lobed odd bipinnate, & elliptic odd

pinnate.

 Many different structures in different leaves.

 Ex: Most have a stem, blades, & nodes. Some

have lateral buds & petioles, differentiating them

from other leaf structures.

 The surface features of leaves can vary widely as well.  Ex: Some have trichomes.

o Root Structure:

 Pericycle is meristematic tissue and gives rise to branch roots.

 Branching of roots is controlled by growth hormones.  Meristem on roots is protected by grouped up

cells at the end of the root.

 Meristem cells differentiate into dermal, vascular,

& ground tissue.

 Some roots adapted to store water & starch, or to be parasitic.

 Many roots morphed and adapted to the environment they live in.

 Ex: Buttress roots, Pneumatophores, & Carrots. We also discuss several other topics like samantha gagne

o Secondary Growth (Woody Plants):

 Cambium is lateral meristem. Don't forget about the age old question of esrm 100

 Vascular cambium gives rise to phloem & xylem.

 Cork cambium gives rise to protoderm.

- Trees can be killed by girdling. Why? When girdling, it destroys the phloem.

o Monocots & Dicots: Anatomical Differences

 Monocots: grasses, lilies, palms, orchids, etc.

 Ex: corn.

 Dicots: everything else.

 Ex: guava, mango, & papaya.

o Artificial Selection:

 Artificial selection for large leaves = kale.

 Artificial selection for apical flower bud = cauliflower.  Artificial selection for later flower bud = broccoli.

 Artificial selection for apical leaf bud = cabbage.

 Artificial selection for axillary leaf bud = brussels

sprouts.

 Artificial selection for lateral stem meristem = kohlrabi.

- Plant Nutrition & Transport

o Macronutrients:

 What is the role of each of these in the plant?

 Light

o To carry out photosynthesis

 Carbon Dioxide (CO2) gas

o To make the sugar (molecule for sugar)

 Oxygen (O2) gas

 Dissolved mineral ions (K+, NO3-, Ca2+, and so

on)

 Water (H2O)

o Use water electrons to make covalent bonds

to connect molecules

o Also helps plants stay upright

o Micronutrients:

 Chlorine- photosystem II cofactor; signaling; solute and electrochemical balances

 Iron- component of chlorophyll and many enzymes; particularly important in electron transfers

 Boron- cross-links polysaccharides in cell walls; also links cell wall polysaccharides to surface of plasma

membrane

 Manganese- component of photosystem II that allows it to catalyze photolysis during light reactions of

photosynthesis; also functional component of many

coenzymes

 Part of the molecule chlorophyll which is what captures photons for the light reaction in

photosynthesis

 Zinc- cofactor for many enzymes; component of many proteins, including auxin receptors and transcription factors

 Copper- cofactor in many proteins and enzymes involved in electron transfer chains (including

plastocyanin of light-dependent reactions), lignin synthesis, detoxification of free radicals

 Molybdenum- cofactor required for nitrogen fixation and for abscisic acid synthesis

o Light:

 Plants adapt to light levels.

 Chloroplast in ground tissue is more full in plants in sun than plants in shade.

 A heterotrophic vascular plant: Monotropa Uniflora (Indian Pipe).

 Has no chloroplast.

 Lives on decayed organic matter.

 Looks like fungus but is not a fungus.

 What about UV?

 They can be protected.

 This is due to special proteins.

o Growth-Limiting Nutrients:

 CO2

 Current atmosphere: only 0.035% (and rising) to saturate photosynthesis: 0.1%.

 Small component in earth’s atmosphere.

 Contributes to the rise in temperature.

 Water

 Helps them stay upright.

 Nitrogen

 Lots in atmosphere, but N2 gas can NOT be used by plants.

 Nitrogen gas is the primary gas in the

atmosphere.

 Plants can only take it up if it has been converted into an ion by water then dispersed through the

soil.

 Nitrogen-fixing bacteria are essential for this

process.

 Phosphorus

 From soil.

 Potassium

 From soil.

 Iron

 Limits algal growth in marine habitats.

 Nitrogen, Phosphorus, & Potassium are the components of chemical fertilizer.

o Nitrogen Fixation:

 Plant roots can only take up N in the form of a soluble compound, such as NH3, NH4+, NO3-, or NO2-.

 Some usable nitrogen and animal urine and feces.  Nitrogen-fixing bacteria.

 1.) A molecule of N2 binds to nitrogenase enzyme.  2.) Three successive pairs of hydrogen atoms

combine with N2 powered by the breakdown of

ATP.

 3.) The 2 molecules of ammonia that formed are released, leaving nitrogenase free to bind more

N2. Ammonia dissolves in cell water to form

ammonium ion (NH4+).

o Nitrogen Uptake by Roots:

 1.) Uptake- Protons (H+) pumped from plant cells provide the driving force for the cotransport of protons (H+) and nitrate (NO3-) into the cytosol.

 2.) Storage- Nitrate can be transported into a vacuole for storage.

 3a.) Assimilation- Cytoplasmic nitrate reductase concerts nitrate (NO3-) to nitrate (NO2-), which enters plastids.

 3b.) In plastids, nitrate reductase converts nitrate to ammonium ion (NH4+). Glutamine synthetase uses NH4+ to synthesize the amino acid glutamine.

o Adaptations for Obtaining Nutrients:

 Some plants get nutrients by dissolving animals  Animal proteins have a lot of nitrogen in them

 Some plants capture insects

 Ex: Sundew Genus Drosera

o Root Hairs:

 Associations between plant roots and fungi in soil called mycorrhizae

 Fungal Hyphae (white hairs) extending from the

top of these roots greatly enhance their surface

area.

 Plant will give the fungus sugar and in return the

fungus will help the plant take up nitrogen.

 Plants grow faster and bigger with fungal hyphae.

 Plant-fungal symbiosis

 Plant-Bacteria Symbiosis

 Cyanobacteria

o Small patches on leaves.

o Plant supplies sugar to the bacteria and

bacteria returns with nitrogen.

 Actinobacteria

o Same with cyanobacteria.

- Bacteria provides nitrogen to the plant; what does the plant give to the bacteria? Carbohydrates

o Legume-Rhizobia Symbiosis (pea family):

 Nodules on roots contain nitrogen

 Nodules give bacteria a place to live

 Bacteria is anerobic

 Grow best in low oxygen

 Produces leghemoglobin

 Binds oxygen in the root nodules and keeps it

away from bacteria

 Convergent evolution

 2 organisms not related that have similar

mechanisms

o Insectivorous Plants:

 Pitcher plants (Nepenthes)

 Insects fall in and can’t get out.

 Venus fly trap (Dionaea Muscipula)

 Leaves close on insects when they land on it.

 Eats insects for its nutrition instead of getting it through their roots

o Parasitism:

 Eats host plant it attaches itself to and gets nutrients like that

 Ex: Dodder (parasitic plant)

 Vines that wrap around host plant and take its

nutrients.

 Ex: Mistletoe

 Grows at top of trees and puts its roots into the

tissue of the host tree.

- What is the function of the root hairs? To increase the surface area for uptake of nutrients for plant

o Transport in Plants:

 Vascular Tissue

 Xylem

 Phloem

 If it is moving up the plant, it is in the Xylem. *

 If it is moving down the plant, it is in the Phloem. *

o Cellular-Level Transport:

 Several roots for the movement of water through plant cells.

 Transmembrane root- molecules repeatedly cross

plasma membranes and cell walls.

 Symplastic root- molecules move through the symplast.  Symplast: continuum of cytosol linked by

plasmodesmata.

 Apoplastic root- molecules move through the apoplast.  Apoplast: water-filled cell walls and intercellular

spaces.

o Transport from Soil to Vascular Bundle:

 Soil water goes up root hair through epidermis, cortex, endodermis, into the primary xylem

 Same with dissolved minerals

 Water goes through transmembrane before it gets to vascular bundle

o Casparian Strips:

 Waxy coating on the cell wall.

 Waterproofs the cell wall.

 Water carrying dissolved minerals travels through endothermal cells.

 Any water going from the root to the vascular bundle has to go through these.

 Allows for control over how much water goes into the vascular bundle.

 IMPORTANT STRUCTURE

 Blocks water from going around the cells; has to go through the cells.

o Xylem Tissue:

 Fluid and materials going up!*

 Vessel elements

 Dead cell

 No cytoplasm

 Slits for cell wall so sap can move from one vessel

to another

 No top

 When cells are stacked on top of each other,

essentially makes a big straw

 Larger diameter

 Tracheids

 What you find in newly formed xylem

 Have a little bit of cytoplasm

 Have holes that allow fluid to move from one

tracheid to another

- When you eat a peach, you are eating tissue derived from the ___? Ovary

o Xylem Transport: Cohesion-Tension:

 How does that transport occur? What makes sap move up to the top of a tall tree? The Cohesion-Tension Model  1.) Water evaporates from aboveground plant

parts, leaves, (a process called transpiration),

mainly through open stomata.

 2.) The evaporation exerts tension (pulls) on the

narrow columns of water that fill xylem tubes. The

tension extends from leaves to roots because

liquid water has cohesion. Hydrogen bonds among

water molecules collectively impart cohesion to

liquid water.

 3.) As long as evaporation continues, the tension

it creates drives the uptake of more water

molecules from soil.

 Water has a high cohesion.

 Water molecules stick together because it makes

hydrogen bonds with other water molecules.

 If you put them in a narrow straw, they can be pulled up fairly easy because of the force of

evaporation of the water content of the tree.

o Adaptations to Reduce Transpiration:

 Ways to reduce the evaporation of water in a plant.  Stoma has guard cells.

 Surrounds the stoma in leaves.

 Opens and closes.

o Stomata:

 When guard cells swell with water, they bend so a gap (the stoma) opens up between them. The gap allows the plant to exchange gases with air.

 When the guard cells lose water, they collapse against each other so the gap between them closes. A closed Stoma limits water loss. It also limits gas exchange.  Water stress results in closure of stomata.

 Stomata opens at sunrise.

 Without opening, plant doesn’t get carbon dioxide for photosynthesis.

 So, the plant has to make a trade off and open, exchanging some of their water intake, to receive carbon dioxide to do photosynthesis.

o Water Stress Results in Closure of Stomata:

 1.) ABA binding to its receptor on a guard cell

membrane causes the release of nitric oxide (NO). The NO activates calcium ion channels in the membrane, so these ions enter cytoplasm.

 2.) The influx of calcium ions activates transport proteins that pump negatively charges malate and chloride ions out of the cells. Thus, the overall charge of cytoplasm increases, and the overall charge of

extracellular fluid decreases.

 3.) The resulting voltage change across the guard cell plasma membranes opens gated transport proteins that allow potassium ions to exit the cells.

 4.) Water follows the solutes by osmosis. The guard cells lose turgor and collapse against one another, so the stoma closes.

o Stomata Open at Sunrise:

 1.) Light-triggered phosphorylation of ATP synthases causes these transport proteins to pump hydrogen ions (H+) out of guard cells.

 2.) The resulting change in voltage across the membranes opens gated transport proteins that allow potassium ions to enter the cell.

 3.) Water follows the solutes by osmosis (takes in water). Turgor increases inside the guard cells, and the stoma opens.

 The guard cells are what determines whether the stomates open or close.

o Water Stress: Leaf Abscission

 Some plants live in dry areas and have to conserve their water.

 Ocotillo with leaves

 Has leaves and flowers when it rains

 Ocotillo without leaves

 Drops its leaves to conserve water when its dry

o Phloem Transport: Pressure Flow

 Fluid and materials going down!

 Has these things called sieve-tubes.

 Pressure Flow Model.

 1.) At a source region, sucrose moves into a

companion cell, then into a sieve tube.

 2.) As a result of the increase in solute

concentration, the fluid in the sieve tube becomes hyper-tonic. Water moves in from the surrounding cells, so phloem turgor increases.

 3.) The pressure difference pushes the fluid from the source to the sink. Pressure and solute

concentrations decrease as the fluid moves from source to sink.

 4.) At a sink region, sucrose moves from the sieve tube into sink cells. Water follows by osmosis.

o Phloem Pressure is High:

 Up to 10 atmospheres (a lot).

 Sap in phloem has lots of sugar.

 It’s good for animals or insects if they can get their mouth on the phloem.

 Ex: an aphid can tap into the phloem to eat and the pressure can be so high that not only will it fill

the aphid, but the sap will also push out from his

butt through his digestive system.

o Iron: A Limiting Micronutrient in the Oceans:

 Oceanic phytoplankton remove C02 from the

atmosphere. How?

 Adding iron to the seawater stimulates the

reproduction and growth of these organisms.

 Iron fertilization of the ocean has been examined

as a possible way to limit the rise of CO2 in the

atmosphere.

o Fecal Pellets from Zooplankton Contain Carbon

 Studies suggest that only 1-15% of the CO2 fixed by phytoplankton reaches the seabed.

 Unintended consequences? Dead Zones.

o Can we control what grows?

 Pseudo-nitzchia which can sometimes produce domoic acid, a toxin harmful to animals and humans.

 Coccolithophorids release dimethyl sulfide, which

eventually encourages cloud formation in the

atmosphere that can block solar radiation and help cool the planet.

- Plant Reproduction-

- When you eat a peach, you are eating tissue derived from what? Ovary

o Alternation of Generations:

 How is it different from animal life cycles?

 In plants, you have haploid life stage that lives for a long time.

 In animals, there isn’t really a “free living” haploid

stage.

o A Major Trend in Plant Evolution: Reduction of the

Gametophyte

 Gametophyte-dominant bryophyte (moss)

 Dependent sporophyte (seed)

 Dominant independent gametophyte (green part)

 Sporophyte-dominant flowering plant (oak)

 Dominant independent sporophyte (green part)

 Dependent gametophytes (seed)

- This evolutionary trend in plant evolution does what? Allows plants to invade more habitats and increases the reproductive success of plants

o Asexual Reproduction

 Some plants can reproduce from runners, leaves,

pieces, etc.

 The offspring are genetically identical to the parent plant.

 Ex: Kalanchoe daigremontiana and Quaking aspen (Populus tremuloides)

 Quaking aspen and Kalanchoe produce many new

shoots/blooms.

 We make use of asexual reproduction in plants: grafting, cuttings, etc.

o Life Cycle of a Flowering Plant:

- Flower Structure

o 1.) Receptacle

 Essentially the stem.

o 2.) Sepal

 All sepals combined form the calyx.

 Small leaf-looking things right under the petals.

o 3.) Petal

 All petals combined form the corolla.

o 4.) Stamens: male gametophyte

 Filament

 Anther

o 5.) Carpels: female gametophyte

 Stigma

 Style

 Ovary

o Carpel structure varies.

o Ovary position varies (can have one or multiple ovaries). o Ovule position varies within ovaries.

o Plasticity in Flowers:

 Perianth

 Calyx (sepals)

 Corolla (petals)

 Androecium (stamens)

 Gynoecium (carpels)

 With sepals, petals, stamens, and carpels it is known as a “complete flower.”

 Some flowers don’t have petals, sepals, etc.

o Perfect Flowers:

 If you have both the male and female gametophytes in the same flower = perfect flower!

 Sepal

 Petal

 Anthers

 Stigma

 Style

o Imperfect Flowers:

 Male and female gametophytes are in separate flowers = imperfect flower!

 Can be monoecious

o Separate male and female flowers on the

same plant.

o Ex: corn

 Can be dioecious

o Plants that have only male flowers or have

only female flowers.

o Ex: holly

o Plasticity in Flower Structure:

 Come in many different forms of plasticity

 The irregular blossom of lady’s slipper

(paphiopedilum).

 Elongated inflorescence of hyacinth (hyacinthus

orientalis).

 A daisy (gerbera jamesonii) is a composite of

many individual flowers.

 Incomplete flowers of eucalyptus (eucalyptus

robusta) have no petals.

 Imperfect flowers: stamen-less female blossoms

of Begonia form on the same plants as carpel-less

male blossoms.

o Inflorescences:

 What is the evolutionary advantage?

 At anthesis they present the flowers in ways that

allow for the transfer of pollen and optimization of

the plant's reproductive success.

 During flower and fruit development they provide

nutrients to the developing flowers and fruits.

o Zucchini:

 This plant is monoecious with incomplete flowers.

- Wind Pollination

o Animal Pollinators:

 Insects

 Blueberry bees (osmia ribifloris) are efficient

pollinators of a variety of plants.

 Birds

 Pollen accumulates on the feathers of a little

wattlebird (anthochaera chrysoptera) sipping

nectar from a torch lily (kniphofia uvaria).

 Mammals

 The large, white flowers of a giant saguaro cactus

(carnegiea gigantea) produces sweet nectar. The

flowers are visited by bats at night, and by birds

and insects during the day.

o Insect Pollinated Flowers Have UV Pigments:

 Dandelion (taraxacum officinale)

 Evening primrose (Oenothera biennis)

o Flowers are Highly Evolved to Attract Their Pollinators:

 Female burnet moths (zygaena filipendulae) perch on purple blossoms – preferably pincushion flowers

(knautia arvensis) – when they are ready to mate. The visual combination attracts male moths.

 A zebra orchid (caladenia cairnsiana) mimics the scent of a female wasp. Male wasps follow the scent to the

flower, then try to copulate with and lift the dark red

mass of tissue on the lip. The wasp’s movements trigger the lip to tilt upward, which brushes the wasp’s back

against the flower’s stigma and pollen.

 Nectar= energy

 Pollen= protein

- Why are the Yucca flowers white? The moths are active at night and they are drawn to the light color of the flower.

o Reproduction in Flowering Plants:

 The process is called Double Fertilization

 One fertilizes the egg and the other fertilizes the

sperm.

 1.) An ovule forms inside a flower’s ovary. A cell in the ovule enlarges.

 2.) Four haploid (n) megaspores form by meiosis and cytoplasmic division of the enlarged cell. Three

megaspores disintegrate.

 3.) In the remaining megaspore, 3 rounds of mitosis with no cytoplasmic division result in a single cell with 8

nuclei.

 4.) Uneven cytoplasmic divisions result in a seven-celled embryo sac with 8 haploid nuclei. This sac is the female gametophyte.

 5.) Pollen sacs form in the anther.

 6.) Four haploid (n) microspores form by meiosis and cytoplasmic division of a cell in the pollen sac.

 7.) In this plant, mitosis of a microspore followed by differentiation results in a two-celled pollen grain.

 8.) Pollen grains are released from the anther. One lands on a stigma and germinates. A cell in the grain develops into a pollen tube; the other, into 2 haploid sperm cells.

 9.) The pollen tube grows down through tissues of the carpel, carrying the two sperm nuclei with it.

 10.) The pollen tube reaches the ovule, penetrates it, and releases the 2 sperm nuclei. One nucleus fertilizes the egg. The other fuses with the endosperm mother

cell.

- Why do flowers undergo double fertilization? To produce the zygote and a source of food for the zygote.

o Pollen Grains Have Species-Specific Morphology:

 Pollen tube initiation and growth in governed by

chemical signal molecules.

 Depending on the plant’s signals whether the

pollen is the same species, it can then grow.

 Some plants can self-pollinate; others can’t.

o Seed Formation:

 Seeds contain a large amount of stored energy; human crop plants produce large nutritious seeds.

 1.) After fertilization, a Capsella flower’s ovary develops into a fruit. An embryo surrounded by integuments

forms inside each of the ovary’s many ovules.

 2.) The embryo is heart-shaped when its 2 cotyledons start forming. Endosperm tissue expands as the parent plant transfers nutrients into it.

 Endosperm is mostly starch.

 Storage of energy.

 Endosperm provides energy for germinating

embryo in seed.

 3.) In eudicots like Capsella, nutrients are transferred from endosperm into 2 cotyledons as the embryo

matures. The developing embryo becomes shaped like a torpedo when the enlarging cotyledons bend.

 4.) A layered seed coat that formed the layers of

integuments surrounds the mature embryo and its 2

enlarged cotyledons.

- Fruits

o Diversity of Fruits:

 Many fruits store their seeds inside.

 Many “vegetables” are fruits

 Ex: Tomato & Pepper

o Simple Fruits:

 If you have one see per fruit.

 Ex: Avocado & Peach

o Compound Fruits:

 If you have multiple seeds per fruit.

 Aggregate Fruit: from a single flower with multiple ovaries.

 Ex: Blackberries & Raspberries

 Multiple Fruit: from an inflorescence; the ovaries of many flowers fuse.

 Ex: Pineapples

o Accessory Fruits:

 Fleshy part from the tissue other than the ovary.

 Ex: Strawberries (exception because the seeds are on the outside).

- Seed Anatomy

o Parts:

 Seed coat

 Endosperm

 Cotyledon(s)

 Coleoptile

 Plumule

 Hypocotyl

 Radicle

o Germination: Monocots

 Meristem is at tip of shoot and to avoid being damaged from soil, Coleoptile develops to protect the shoot.

 1.) As a corn grain (seed) germinates, it’s a radicle and coleoptile emerge from the seed coat.

 2.) The radicle develops into the primary root. The coleoptile grows upward and opens a channel through the soil to the surface, where it stops growing.

 3.) The plumule develops into the primary shoot that emerges from that emerges from the coleoptile and

begins photosynthesis.

o Germination: Dicots

 Don’t have a hypocotyl.

 1.) The seed coat splits, and the radicle emerges.

 2.) As the hypocotyl emerges from the seed, it bends in the shape of the hook.

 3.) The stem lengthens, and the bent hypocotyl drags the 2 cotyledons upward toward the surface of the soil.  4.) Exposure to sunlight causes the hypocotyl to

straighten.

 5.) Primary leaves emerge from between the cotyledons as the stem straightens.

 6.) The cotyledons wither as the seedling’s leaves begin to produce food by photosynthesis. Eventually, they fall off the stem.

- Seed Dispersal Mechanisms

o Animals:

 Seeds can fall off of trees and get stuck to animals. Proceeding to then falloff in a new location and grow.

 Or the plant gives an animal a fruit that they can eat then disperse the seeds.

o Wind:

 Some plants make their seeds light so they can be taken to a new location by the wind blowing.

o Water:

 Many plants that are next to water rely on the water to take seeds to new destinations and provide them with water to grow.

 Ex: Coconuts can wash up onto the shore and sprout in a new location.

 Charles Darwin did experiments to see if seeds could survive exposure to seawater.

 Kept seeds in sea water for a bit then took them

out to see if they would germinate.

 Conclusion: most did!

o A Botanical Mystery:

 Tambalacoque tree (Sideroxylon grandiflorum)

o Senescence:

 Loses leaves to retain the water.

 Leaves of sugar maples (Acer saccharum) native to the northeastern U.S. and Canada change color and drop

from the trees in September. The trees remain dormant throughout winter, when prolonged cold would

otherwise damage tender leaves.

 Teak trees (Tectona grandis) native to south Asia lose their leaves and become dormant during the region’s summer dry season, which is November through May. New growth that appears in early June is supported by

monsoon rains.

 Controlled by Ethylene

- Why do flowers undergo double fertilization? To produce the zygote and a source of food for the zygote.

- Plants: Hormones & Responses to the Environment

o Plant Hormones:

 Chemical signal messenger molecules.

 Right (small) plant: wild type.

 Left (large) plant: auxin signal transduction mutant; auxin activated second messenger pathway is always active.

o Plants Respond to a Variety of Stimuli:

 Physical Stimuli

 Environmental:

o Light

o Atmospheric gasses including CO2

o Humidity

o Temperature

o Touch, wind

o Gravity

o Soil water

o Rocks & other barriers

o Soil minerals

 Biological Stimuli

 Internal:

o Hormones

 Environmental:

o Herbivores

o Agricultural hormone applications

o Pathogens

o Organic chemicals emitted by other plants

o Soil microorganisms

- Plant Discoveries in Growth Stimulants

o Charles & Francis Darwin’s Experiments (1870’s):

 Used oat seedlings.

 Planted oat seedlings and put a black cap over one, and a clear cap over another.

 Conclusions:

 1.) Tip senses direction of light.

 2.) Bending region does not sense light, but it

responds to some signal from the tip.

 3.) The black cap stopped the seedling from

turning to the light.

o Boyen-Jensen (1913):

 Porous gelatin placed between tip and shoot.

 Impenetrable barrier between tip and shoot.

 Conclusion: The gelatin allowed the shoot to send a signal from the tip to the shoot, where the impenetrable barrier did not.

- What do you conclude from this experiment? The “signal” from the tip of the shoot is a chemical.

o Went (1920):

 Cut oat seedling tips.

 Tips placed on agar.

 After a few hours, cut agar into small blocks and place on top of oat coleoptiles with tips removed.

 Conclusion: the cells that get more of the chemical elongate.

 Went named the chemical “auxin” (Greek “to increase”).  The chemical structure of auxin was determined a few years later. It is indole acetic acid (IAA).

o Auxin is a Growth Hormone:

 1.) Influx carriers actively transport auxin into the cell; efflux carriers actively transport it out. Efflux carriers

positioned asymmetrically in the membranes direct the flow of auxin in a particular direction.

 2.) Efflux carries cells in a lengthening shoot tip direct auxin downward through the stem.

 3.) Auxin enters a root tip in vascular tissue. Efflux carriers direct its flow through epidermal cells in the

root tip.

o Cytokinin: Stimulates Cell Division in Meristems:

 Stimulates growth of branches.

 1.) Auxin flowering through a shoot keeps the level of cytokinin low in the stem.

 2.) Removing the tip ends auxin flow in the stem. As the auxin level decreases, the cytokinin level rises.

 3.) The cytokinin stimulates cell division in apical meristem of lateral buds. The cells begin to produce auxin.

 4.) Auxin gradients form and direct the development of the growing lateral buds.

o Auxin & Cytokinin Influence Growth Form:

 Stem can be cut in half and many new stems can sprout from lateral buds.

 The cut stem’s sprouts can become equal in size or larger than the uncut stem.

o Interaction Between Cytokinin & Auxin:

 Lateral buds inhibited by auxin levels.

 Auxin is highest in the shoot tip and gradually gets lower going down to the root tip.

 Lateral buds develop into branches (optimal ratio of auxin to cytokinin).

 Branches previously stimulated to sprout.

 Lateral roots develop (optimal ratio of cytokinin to auxin).

 Lateral roots inhibited by high cytokinin levels.  Cytokinin is highest in the root tip and gradually gets lower going up to the shoot tip.

o Gibberellin:

 Another growth hormone.

 Plays a large part in stem elongation and seed germination.

 Many dwarf varieties of plants (including Mendel’s dwarf peas) are due to mutant gibberellin receptors.

 1.) Absorbed water causes cells of a barley

embryo to release the gibberellin, which diffuses through the seed into the aleurone layer of the

endosperm.

 2.) Gibberellin triggers cells of the aleurone layer to express the gene for amylase. This enzyme

diffuses into the starch-packed middle of the

endosperm.

 3.) The amylase hydrolyzes starch into sugar

monomers, which diffuse into the embryo and are used by the reactions of aerobic respiration.

Energy released by the reactions of aerobic

respiration fuels meristem cell division in the

embryo.

o Abscissic Acid (ABA):

 A stress hormone.

 Promotes dormancy in seeds

 In desert plants, rain washes ABA out of the seed:

germination.

 Also closes stomates during water stress.

o Ethylene: Fruit Ripening

 Promotes ripening of fruit.

 For example, high ethylene production in the strawberry flower.

 Ethylene levels get consistently lower as the petals drop, fruit forms, and the green strawberry fruit

enlarges.

 Once the fruit forms, the ethylene levels start to rise again and consistently rise until the fruit is mature.

 Ethylene also stimulates senescence and dropping in leaves.

- Responses to Environment Stimuli

o Positive Phototropism:

 Sunlight strikes only one side of the coleoptile.

 Auxin flow is then directed toward the shaded side, so cells on that side lengthen more (growing sideways).

o Thigmotropism:

 Some plants will curl around others.

 The turning or bending of a plant or other organism in response to a touch stimulus

 Ex: M. pudica

o How M. pudica Folds its Leaves:

 Leaf of a sensitive plant, M. pudica, is either touched by something or moved by the wind activating the action potential of the leaf.

 K+ and Cl- then exit from the parenchyma cells near the lower leaflet surface, causing H2O to also exit.

 These cells then flatten, causing the leaflets to fold upward and have the appearance of closing.

o Gravitropism:

 Shoot and Root Cells Have Opposite Responses to Auxin.  Positive response to gravity in root (grows down).

 Negative response to gravity in shoot (grows up).

o Shoot Bends Upward:

 1.) Shoot tip produces auxin.

 2.) Auxin accumulates on lower side, stimulating cell elongation, and bending the shoot upward.

o Root Bends Down:

 3.) Auxin enters the root, and root cap cells direct auxin to the lower side.

 4.) Root cell elongation is inhibited by auxin, so the root bends downward.

- Day Length & Flowering-

 Flowering is controlled by night length, not day length.  A.) A flash of red light interrupting a long night

causes plants to respond as if the night were

short. Long-day plants flower; short-day plants do

not.

 B.) A flash of far-red light cancels the effect of a

red light flash. Short-day plants flower; long-day

plants do not.

 Some plants are day-neutral; night length has no effect on flowering.

 Ex: Iris flowers in response to short summer nights. Whereas Goldenrod does NOT flower then.

 Iris + short summer nights = flowers

 Goldenrod + short summer nights = no flowers

 Ex: Goldenrod will flower when nights are longer in fall. Whereas Iris does NOT flower then.

 Iris + long fall nights = no flowers

 Goldenrod + long fall nights = flowers

 Ex: A light flash interrupting long nights will allow Iris to flower but will prevent flowering in Goldenrods.

 Iris + light flash + long nights = flowers

 Goldenrod + light flash + long nights = no flowers

o Vernalization:

 When a seed has to have a certain amount of time in cold temperature for the plant to germinate and flower.  Ex: Tulips

o Photoreceptors:

 Phytochrome (protein that senses the light): red light  First light sensing protein source found in plants that senses red light.

 1.) Pr, the inactive conformation of phytochrome,

occurs in the cytosol and is a receptor for red

light.

 2.) Red light activates phytochrome, converting it

to Ptr, a receptor for far-red light.

 3.) Activated Ptr moves into the nucleus, where it

interacts with specific proteins, thereby regulating

genes and causing responses such as seed

germination.

 Cryptochromes, Phototropin: blue light

 Other newer light sensing protein sources later

found in plants that sense blue light.

 Found after Phytochrome.

o Phytochrome & Seed Germination:

 Red light= Pr (inactive) -> Pfr (active)

 Far-red light= Pfr (active) -> Pr (inactive)

 In darkness, seeds do NOT germinate because the

phytochrome remains in the inactive Pr

conformation.

 Even a brief exposure to red light generates the

active Ptr conformation of phytochrome, meaning

the seeds DO germinate.

 Exposure to far-red light after red-light exposure

converts active Ptr to inactive Pr, so seeds do NOT

germinate.

 Exposure to red light after far-red light switches

phytochrome back to the active Ptr conformation,

so the seeds DO germinate.

 The most recent light exposure determines

whether phytochrome occurs in the active Ptr or

in the inactive Pr conformation. If the latter, most

seeds do NOT germinate.

- Plant Defenses-

 ROI (reactive oxygen intermediates -> H2O2 hydrogen peroxide)

 Used in a way to damage the protein bacteria in

fungi.

 Our bodies also produce ROIs as a defense

mechanism.

 Chitinases

 Used as antifungal agent.

 Proteinase inhibitors

 Inhibit breakdown of protein in bacteria.

 Messing with metabolism of bacteria or fungi.

 Terpenes (essential oils, etc.)

 Proteins making plant gross to insects.

 Ex: eucalyptus oil

 Alkaloids (caffeine, nicotine, strychnine, etc.)

o Response to Herbivory:

 1.) Mouth secretions from herbivores and cell damage induce plants to produce the defense hormones

systemin and jasmonic acid.

 2a.) Jasmonic acid travels in phloem or through the air to undamaged tissues, inducing defensed throughout the plant.

 2b.) Volatile compounds from the damaged plant signal to undamaged neighbor plants, which may lead to the production of defense compounds or attract enemies of the attackers.

o Plants Can Summon Help When Attacked:

 1.) Saliva of a tobacco budworm (Heliothis virescens) chewing on a leaf of a tobacco plant (Nicotiana) triggers the plant to emit a combination of 11 volatile secondary metabolites.

 2.) Red-tailed wasps (Cardiochiles nigriceps) are

attracted to the unique chemical signature emitted by the plant. They follow the trail of aromatic chemicals

back to the source.

 3.) A wasp that finds the budworm attacks it and

deposits an egg inside of it. When the egg hatches, a larva emerges and begins to eat the budworm, which eventually dies.

- Plant Hormones are Used Commercially-

 Cytokinin inhibits senescence.

 Florists spray cut flowers with cytokinin to inhibit

senescence and prolong life of flowers.

 Ex: Grapes & Bananas

 Seeds produce gibberellin, seedless grapes make

small fruit unless treated with the hormone.

- If you have a green banana, what hormone would you add to make it ripen faster? Ethylene

o Can Plants Tell Time?

 Yes, they can!

 Ex: long day and short day flowers previously

mentione

 Phyllostachys bambusoides in flower (bamboo).

 Bamboo only flowers, depending on species, once every 130 years and once they produce seeds,

they die.

 Specimens grown from cuttings in greenhouses

around the world flower on exactly the same day

as the parent plants in the wild.

- Animal Diversity-

 3 domains.

 Domain Eukarya

 Fungi

 Plant

 Proteus

 Animals

 Kingdom Animalia

 About 25 phyla in animal kingdom.

o Metazoan Origins:

 3 theories

 1.) Syncitial ciliate ancestor.

 2.) Colonial flagellate.

 3.) Polyphyletic.

o Colonial Theory:

 Choanoflagellates are ancestral to all metazoans

o Choanflagellate Colony to Sponge:

 A.) Daughter colony formation (asexual method).

 B.) Female gamete and spore formation.

 Asconoid (Leucosolenia).

 C.) Male gamete formation.

o Choanocyte Colony to Jellyfish:

 Blastaea forms into Planuloid Ancestor

- PHYLUM PORIFERA-

o Sponges:

 Cellular grade – no tissues.

 No mouth or gut.

 Sponges are a rich source of natural products: potential drugs.

 Ex: Red boring sponge, encrusting sponge, finger

sponge, variable sponge, & tube sponge.

o Types of Cells:

 Mesohyl- gelatinous matrix

 Collencyte- secretes collagen

o Structure:

 Choanocytes line spongocoel.

 Choanocytes line radial canals.

 Choanocytes line chambers.

o Skeletal Elements:

 Siliceous spicules (Hexactinellida).

 Siliceous spicules (Demospongiae).

 Spongin.

 Calcareous.

o Classes:

 1.) Calcarea

 2.) Hexactinellida

 3.) Demospongidae

- PHYLUM CNIDARIA-

 Radial symmetry.

 Nematocysts.

 Nerve net.

 Polyp or medusa body form.

 Polyp type has a stem-like body and the mouth

and tentacles are on the top.

 Medusa type has no stem-like body and the mouth and tentacles are on the bottom.

 Gastrovascular cavity.

 Sexual or asexual reproduction.

o Feeding:

 Cnidocyte with discharged nematocyst.

 Cnidocyte with undischarged nematocyst.

o Class Hydrozoa:

 Most are small.

 Variable body form, many are colonial.

 Medusae have a velum.

o Wind-Powered Hydrozoans:

 Vellela- by the wind sailor.

 Physalia- Portuguese man of war.

- Class Scyphozoa (Jellyfish)-

 Reproduction of polyp stage.

 No velum.

o Scyphozoan Diversity:

 Chrysaora- sea nettle.

 Aurelia- moon jellyfish.

 Cyanea capillata- sea blubber.

 Stomophilus- cannonball.

o Class Cubozoa (box jellies):

 Carybdea marsupialis

 Has a longitudinal section.

o Class Anthozoa:

 Anemones, Corals, etc.

 No medusa stage.

o Corals:

 Consists of:

 Tentacles

 Mouth

 Pharynx

 Septum

 Gastrovascular cavity

- Biogeography of Coral Reefs:

 Reef coral communities – average 20 degrees Celsius isotherm.

o Australia’s Great Barrier Reef at Low Tide:

 Shows a lot of the coral reef communities above water level.

o Phylum Ctenophora (comb jellies):

 Has comb plates.

 No nematocysts.

 No homeobox genes.

 Ex: Mnemiopsis leidyi

 Common in Louisiana waters; bioluminescent.

o Comb Jellies Invade Black Sea:

 In Europe.

o A Tale of Two Jellies:

 Mnemiopsis leidyi & Beroe ovata.

 Beroe invaded the Black sea in 1999 and the density of Mnemiopsis has decreases dramatically.

 First reported in the Black Sea in 1982.

 1989: 15 individuals/ft^3.

 Each animal filters 4 liters of seawater daily.

 Black Sea fisheries collapsed.

 Has spread throughout European waters.

 Fisheries are recovering.

- PHYLUM PLATYHELMINTHES

o Flatorms:

 Class Turbellaria: Free-living forms.

 Class Monogenaea: Parasites with a single host in the life cycle.

 Class Trematoda: Parasites with 2 or more hosts.

 Class Cestoda: Tapeworms.

- PHYLUM NEMERTEA

o Ribbon Worms:

 1.) Complete gut.

 2.) Phynchocoel with evertible proboscis.

 3.) Flame cells.

 4.) Acoelomate.

o PSEUDOCOELOMATE PHYLA:

 (A few are missing).

 Nematoda (round worms)

 Nematodes can be either free-living or parasitic.

 Kinorhyncha

 Gastrotricha

 Gnathostomulida

 Rotifera

- PHYLUM ANNELIDS

o Segmented Worms:

 They have elongated, more or less cylindrical bodies divided by grooves into a series of ring-like segments.  The bristles are called cheates.

o Class Polycheata:

 Ex: bloodworms & rag worms.

o Class Oligocheata:

 Ex: earthworms, etc.

o Class Hirudinea (Acheata):

 Ex: leeches

o Methane Ice Worms:

 Occur on clathrates in the Gulf of Mexico.

 The worms eat methanotrophic bacteria on the surface of the gas hydrates.

 Referenced to as “The Caviar of the South Pacific” because people eat the worms for nutrition.

 Ex: Hesioceaca methanicola

o Swarming:

 Occurs only in a few polycheate species.

 Ex: a Heteronereid.

 Eunica viridis– the Samoan palolo worm.

- PHYLUM MOLLUSCA-

 Second most diverse group.

 Characteristics:

 1.) Radula

 2.) Cilinary tracts

 3.) Mantle and shell

 Has 50,000 species – include largest invertebrates.  Tridacna gigantea: 1.5 m long and 225 kg.

 Architeuthis: 18 m long, 450 kg.

 Octopus & squid have large brains, highly

developed sense organs, and complex behavior.

o Classes of the Mollusca:

 Monoplacophora

 Gastropoda (gastropods)

 Snails

 Cephalopoda (cephalopods)

 Octopus & Squid

 Bivalvia (bivalves)

 Clams & Oysters

 Scaphopoda

 Polyplacophora

 Solenogastres

 Caudofoveata

o Class Gastropoda:

 Snails (35,000 species).

 Ex of shells: Busycon carica (knobbed whelk) & Busycon contrarium (lightning whelk).

 Torsion during larval development.

 They rotate their bodies in the shell 180 degrees during development.

 Some gastropods lack a shell.

 Sea slugs

 Most gastropods have a shell (all different kinds).  Ex: Drake’s Moon Snail, Common Purple Sea-Snail, etc.

 Shells consist of:

 Apex

 Spire

 Whorl

 Body whorl

 Aperture

 Inner lip

 Outer lip

 Siphonal canal

o Class Bivalvia:

 Bivalve means “2 shells”

 1.) Body laterally compressed, shell with 2 valves.  2.) Large mantle cavity and gills.

 3.) Foot adapted for burrowing because they have no head.

 Ex: Common Jingle Shell (1.5 in) & Hooked Mussel (1.5 in).

 (Many different kinds of shells).

o Class Cephalopoda:

 Considered most intelligent.

 The zenith of invertebrate evolution.

 All marine.

 Their heads project into a ring of tentacles derived from the foot.

 They are active predators.

 Ex: The Cuttlefish (no outer shell)

o Oysters as Ecosystem Engineers:

 Oysters are bivalve.

 Builds up oyster reefs to serve as a physical barrier for storms etc but also clean the water.

 Traps particles on gills.

 A single oyster can filter 50 gallons of water in a day.

o Ribbed Mussels as Ecosystem Engineers:

 Base of marsh grass.

 Also filter large amounts of salt-water.

- Living Shorelines-

 Some people use molluscs to prevent erosion (living shoreline).

o PHYLUM ARTHROPODA:

 Most diverse group (arthopods).

 Mostly everything with a hard, outer shell.

 A vast assemblage of animals (800,000 species).

 1.) Exoskeleton of calcifies chitin (shell).

 2.) Molting.

 3.) Open circulatory system.

 Annelid affinities:

 1.) Metamerism.

 2.) Nervous system.

o Arthropod Groups:

 Traditional Phylogeny:

 Ancestral Arthopod

o Trilobites (extinct)

o Chelicerates

 Eurypterids (extinct)

 Horseshoe crabs

 Arachnids

 Sea spiders

o Mendibulates

 Insects

 Centipedes

 Millipedes

 Revised Phylogeny:

 Ancestral Arthopod (A Crustacean?)

o Trilobites (extinct)

o Chelicerates

 Eurypterids (extinct)

 Horseshoe crabs

 Arachnids

 Sea spiders

o Myriapoda

 Centipedes

 Millipedes

o Crustaceans

 Insects

 Modern crustaceans (crabs)

o Chelicerates:

 Spiders, ticks, scorpions, horseshoe crabs, etc.  More species by far than any other animal.

 The name comes from the fangs they have.

o Myriapoda:

 Centipedes and millipedes.

 Centipede has one pair of legs per segment and millipedes have 2 pars of legs per segment.

- Crustacean Diversity-

 Many different kinds and looks.

o Decapods:

 Ex: Lobster, Crabs, & Shrimp.

 Lobster consists of:

 Cephalothorax

o Eye

o Cheliped

o Antennule

o Antenna

o Walking legs

 Abdomen

o Swimmerets

o Telison

o Uropod

o PHYLUM ECHINODERMATA:

 Deuterostomes (related to chordates).

 Dermal endoskeleton.

 Secondary pentamerous radial symmetry.

 Ex: starfish & sea urchin.

- PHYLUM CHORDATA (humans)-

o Chordate Hallmarks:

 1.) Notochord (structural element).

 Consists of a Fibrous Sheath and an Elastic

Sheath.

 2.) Dorsal nerve cord (spinal cord).

 3.) Pharyngeal pouches.

 4.) Post-anal tail.

 Ex: Calcichordate Echinoderms (fossil).

 Has pharyngeal slits.

 Thought of as an early offspring of ancestral

animals.

o Subphylum Urochordata:

 Ex: Tunicates (sea squirts).

 They are clear.

 They filter feed.

 They consist of:

o Incurrent siphon

o Nerve ganglion

o Excurrent siphon

o Pigment spots

o Atrium

o Genital duct

o Anus

o Intestine

o Tunic

o Stomach

o Stolons

o Gonads (ovary & testes)

o Heart

o Mantle

o Pharyngeal slits

o Endostyle

o Pharynx

o Tunic

o Sensory tentacles

o Urochordate Metamorphosis:

 Subphylum Cephalocord Lancelets

 Have notochord, post-anal tail, pouches, etc.

 Filter feeders.

o Subphylum Vertebrata (Craniata):

 Has backbone and skull.

 Ex: humans.

- Which group of vertebrates has the most species? Fish - Fish

o Jawless Fish:

 Hagfish

 Feed on dead animals in ocean.

 Lamprey

 Hooks themselves on prey fish and digest them

from inside out.

 Condrichthytes: sharks, rays, ratfish (no hard

backbone).

 More advanced fish have jaws.

o Bony Fish:

 Backbone is calcified and hard.

 24,000 species.

 Enormous diversity.

 Ray finned

o Ex: Seahorses

 Lobe finned

o Ex: Australian lungfish

- Evolution of Early Tetrapods-

 How do we get something that looks like a fish, turn into a frog?

 Euthenopteron bone evolution:

 Cleithrum

 Humerous

 Ulna

 Ulnare

 Dermal fin rays

 Intermedium

 Radius

 Clavicle

 Skull

 Acanthostega bone evolution:

 Radius

 Phalanges

 Humerous

 Ulna

 Carpals

 Ichthyostega bone evolution:

 Pelvis

 Femur

 Tibia

 Fibula

 Fibulare

 Tarsals

 Phalanges

 Limnoscelis bone evolution:

 Humerous

 Ulna

 Carpals

 Radius

 Phalanges

o Class Amphibia:

 Order Gymnophiona: Caecilians

 Order Caudata: Salamanders

 Order Anura: Frogs & Toads (amphibians).

 Have to stay where its wet because they lose water rapidly through skin.

 Some frogs and toads have adapted better to dry land with thicker skin and wax coating on skin.

o Class Amniota:

 All amphibians have to go back to water to lay eggs.  Amniotes don’t need to go back to water to reproduce.  First real land animal independent from water reproduction.

 Has scales for waterproofing.

 Scales consist of:

 Epidermis

 Dermis

 Osteoderm

 Melanophores

 Flexible hinge

o Subclass Anapsida:

 Based on number of holes in skull (no holes).

 Turtles

 Has Anapsid skull (means no holes in skull except for eyes).

 Orbit (eyes)

o Subclass Diapsida:

 Means there is additional 2 holes in skull other than eyes.

 Order Squamata: Lizards, Snakes, Birds.

 Have Diapsid skull.

 Dorsal temporal opening.

 Lateral temporal opening.

 Orbit (eyes).

o Synapsids:

 Have 1 hole in addition to the eye.

 Mammals and their ancestors (humans).

 Mammals have hair.

 They also have mammary glands.

- Groups of Mammals-

 Monotremes: lay eggs.

 Spiny anteater and Platypus

 Marsupials: embryonic offspring grows in mother’s pouch.

 Kangaroo

 Placentals: embryonic offspring grows inside mother’s placenta before being born.

 Humans

o Placental Mammals: Diversity

 Has placenta in the egg.

 Ex: Dolphins, seals, monkeys, elephants, polar bears, etc (DIVERSE).

o Minor Orders:

 Hyrax

 Manatees

 Pangolin

 One of the most endangered animals.

 Chinese medicine takes their scales.

 Aardvark

 Colugo (flying lemur)

- Which group of placental mammals has no teeth? Xenartha (ant eaters)

- Animal Structure & Temperature Regulation

o Parts:

 A.) Cell (cardiac muscle cells)

 B.) Tissue (cardiac muscle)

 C.) Organ (heart)

 D.) Organ System (circulatory system)

 E.) Organism (human)

- Fat cells are a type of what? Connective tissue

- Tissues-

 Cells that sit on basement membrane.

o Animal Tissues: Epithelial

 Simple squamous epithelium

 Lines blood vessels, the heart, and air sacs of

lungs.

 Allows substances to cross by diffusion.

 Simple cuboidal epithelium

 Lines kidney tubules, ducts of some glands, and

reproductive tract.

 Functions in absorption and secretion; movement

of materials.

 Simple columnar epithelium

 Lines some airways and parts of the gut.

 Functions in absorption and secretion; protection.

o Animal Tissues: Connective

 There is a lot of diversity – form follows function!

 1.) Loose connective tissue

 Consists of collagen fiber, fibroblast, and elastic

fiber.

 Underlines most epithelia.

 Provides elastic support and serves as a fluid reservoir.

 2.) Dense, irregular connective tissue

 Consists of collagen fibers (an elastic protein).  In deep skin layers, around intestine, and in kidney capsule.

 Binds parts together, provides support and protection.

 3.) Dense, regular connective tissue

 Consists of collagen fibers and fibroblast.

 In tendons connecting muscle to bone and ligaments that attach bone to bone.

 Provides stretchable attachment between body parts.

 4.) Cartilage

 Consists of glycoprotein (like jello) – rich matrix with fine collagen fibers, and cartilage cell

(chondrocyte).

 Internal framework of nose, ears, and airways; covers the ends of bones.

 Supports the soft tissues, cushions bone ends at joints, and provides a low-friction surface for joint movements.

 5.) Adipose tissue

 Consists of a nucleus and a fat cell (adipocyte) bulging with stored fat.

 Underlies skin and occurs around heart and kidneys.

 Serves in energy storage, provides insulation, and cushions and protects some body parts.

 6.) Bone tissue

 Consists of compact bone tissue, blood vessel, and bone cell (osteocyte).

 Makes up the bulk of most vertebrate skeletons.  Provides rigid support, attachment site for muscles, protects internal organs, stores minerals, and produces blood cells.

 7.) Blood

 Consists of plasma (fluid portion of the blood), white blood cell, red blood cell, and platelet.

 Flows through blood vessels and heart.

 Distributes essential gases and nutrients to the cells; removes waste from them.

o Animal Tissues: Muscle

 Function= movement

 Skeletal and cardiac muscle is called striated muscle.  2 major types: striated muscle and smooth muscle.  Skeletal muscle (striated)

 Long, multinucleated, cylindrical cells with

conspicuous striping (striations).

 Pulls on bones to bring about movement and maintains posture.

 Reflex activated, but also IS under voluntary

control.

 Cardiac muscle (striated)

 Striated, branching cells (each with a single

nucleus) attached end to end.

 Found only in the heart wall.

 Contraction is NOT voluntary control.

 Smooth muscle

 Cells with a single nucleus, tapered ends, and no striations.

 Found in the walls of the arteries, the digestive tract, the reproductive tract, the bladder, and

other organs.

 Contraction is NOT under voluntary control.

o Animal Tissues: Nervous

 Includes support cells, such as glial cells.

 Function= communication

 Cells activate action potential electrical signal.

o Organs are Formed from Tissues:

 Many pieces of tissue put together.

 The layers of muscle tissue in the lumen of stomach:  Simple columnar epithelial tissue.

 Connective tissue.

 Small artery and vein.

 Layers of smooth muscle tissue.

 Nervous tissue.

 Connective tissue.

 Simple squamous epithelial tissue.

o Organ Systems in Animals:

 Many types!!!

 Integumentary System (skin)

 Protects body from injury, dehydration, and pathogens; controls its temperature; excretes certain wastes; receives some external stimuli.  Nervous System

 Uses electrical messengers.

 Detects external and internal stimuli; controls and coordinates the responses to stimuli; integrates all organ system activities.

 Muscular System

 Moves body and its internal parts; maintains posture; generates heat by increases in metabolic activity.

 Skeletal System

 Supports and protects body parts; provides muscle attachment sites; produces red blood cells; stores calcium and phosphorus.

 Circulatory System

 Rapidly transports may materials to and from interstitial fluid and cells; helps stabilize internal pH and temperature.

 Endocrine System

 Uses chemical messengers.

 Hormonally controls body functioning; with nervous system integrates short- and long-term activities. (Male testes added).

 Lymphatic System

 Works with your immune system.

 Collects and returns some tissue fluid to the bloodstream; defends the body against infection and tissue damage.

 Respiratory System

 Rapidly delivers oxygen to the tissue fluid that bathes all living cells; removes carbon dioxide wastes of cells; helps regulate pH.

 Digestive System

 Ingests food and water; mechanically and chemically breaks down food and absorbs small molecules into internal environment; eliminates food residues.

 Urinary System

 Maintains the volume and composition of internal environment; excretes excess fluid and

bloodborne wastes.

 Reproductive System

 Female: Produces eggs; provides a protected and nutritive environment for the development of new individuals.

 Male: Produces and transfers sperm to the female.  Hormones of both systems also influence other organ systems.

o Homeostasis:

 Can have 2 different responses to life: conformity or regulation.

 Maintenance of constant conditions in the cytoplasm.  Humans regulate almost everything (body temp., blood pH, etc).

 A.) Temperature conformity

 When a salmon enters a river from the sea, its body temperature (including blood temperature)

changes if the river water is warmer or cooler than the ocean water.

 B.) Chloride regulation

 The salmon’s blood Cl- concentration remains almost constant, even though the river water is

very dilute in Cl- and seawater is very

concentrated in Cl-.

o Regulation of Blood Glucose Level:

 Without compensatory mechanisms, glucose levels would rise much higher.

 A prolonged fast may cause glucose levels to decrease.  Endocrine changes restore glucose to a normal level.  Nervous and endocrine changes help prevent glucose levels from falling farther as a fast continues.

 Your glucose level spikes when a sugary meal is consumed.

 Body usually tries to maintain homeostasis.

o Negative Feedback: An Important Mechanism

 A.) Model:

 House gets hot.

 Thermostat senses it.

 Thermostat cools down house.

 Thermostat shuts down.

 B.) Physiological example:

 Body gets too cold.

 Hypothalamus sends signals to skeletal muscle.

 You start shivering, which produces heat.

 You warm up.

 Your body stops shivering.

o Smaller Animals Have Higher Metabolic Rates:  Why?

 Shrews have a very high metabolic rate whereas elephants have a very low metabolic rate.

 The surface area of the animals compared to their volume.

 If you’re a warm-blooded animal, you’re losing heat.

 A shrew loses heat faster than an elephant, so it’s metabolic rate is higher.

 Endotherms

 Endo=inside.

 Maintain a fairly stable body temperature despite swings in the environmental temperature.

 Ex: rabbits or humans

 Ectotherms

 Ecto=outside.

 Body temperature is the same as outside.

 Have a body temperature similar to that of their surroundings.

 Ex: bearded dragons

o Heterothermy:

 Animal can maintain body temperature slightly above ambient.

 Means they are in between Endothermia and

Ectothermia.

 Ex: sharks

 What is advantage?

 If water is 15 degrees, the prey fish is also 15

degrees. If the shark is warmer, it can swim faster than the fish.

o Circulatory Heat Exchange in Heterotherms:

 “Cold” Fish:

 1.) Heart pumps blood to gills.

 2.) In gills, blood is oxygenated and comes to

same temperature as the water.

 3.) Cold blood flows from the gills to the body in arteries just under the skin.

 4.) Blood flowing into muscles in arteries is

warmed by blood flowing out of muscles in veins;

heat remains in muscles.

 5.) Veins return blood to the heart.

 “Hot” Fish:

 1.) Heart pumps blood to the gills.

 2.) In gills, blood is oxygenated and comes to

same temperature as the water.

 3.) Cold blood flows through center of fish in

aorta.

 4.) Arteries carry blood to tissues.

 5.) Veins return blood to the heart.

o Circulatory Heat Exchange in Endotherms:

 A whale takes in big mouthfuls of cold water, so makes heat loss.

 Artery surrounded by veins on the whale’s tongue

reduces heat loss.

o Mechanisms of Energy Exchange with the Environment:  Heat from the sun radiates into the body, and heat from the body radiates into the air.

 Heat is released by evaporation due to panting.

 The wind cools the body by convection.

 Heat from the body is transferred into cooler water by

conduction.

- Adaptations to Cold

o Examples:

 Homeoviscous (cellular level)

 Behavioral

 Antifreeze

 Heat Exchangers

o Homeoviscous Adaptation:

 Biochemical changes in lipids.

 Higher temperature (hot)= more loose.

 Lower temperature (cold)= more tight.

www.pbs.org/wgbh/nova/nature/frozen-frogs.html

o Torpor:

 Hummingbirds go into torpor.

 To conserve energy, they grab onto branch and they drop heart rate and body temperature until they warm back up.

o Hibernation:

 Torpor that lasts a long time.

 State of inactivity and metabolic depression in endotherms.  Refers to a season of heterothermy characterized by low body temperature, slow breathing and heart rate, and low metabolic rate.

o “Winter Sleep” in Bears:

 Bears don’t truly hibernate because their body

temperatures stay the same and do not go down.

 Bears go into a “winter sleep” in winter to preserve their warmth and food supply by slowing their heart rate.

 They escape the cold and because food is scarce.

 To get ready for their “winter sleep”, animals will usually eat more than usual during the fall to store up body fat.

o Antifreezes:

 Preventing heat loss from inside.

 When the water around a cell freezes, there is less water to be soluble so the cells will shrink down and damage occurs.  Animals add antifreeze molecules to their body fluid to prevent this.

o Insulation:

 Preventing heat loss from outside.

 For cold water= blubber (sea lion).

 For cold air= fur (bobcat).

 Some animals have both (polar bear).

- Adaptations to Heat

o Examples:

 Homeoviscous

 Behavioral

 Insulation

 Heat Exchangers

 Evaporative Cooling

 Absorption of Water Vapor

o Behavioral Temperature Regulation:

 A lizard’s activity level depends on its temperature (needs to be warm).

 A lizard basking in the sun will have a higher body

temperature than a lizard in the shade or burrow.

 The lizard can change its location in order to regulate its body temperature correctly to survive.

o Insulation:

 Ex: Arabian Oryx (Oryx leucoryx)

 Lives in desert but has fur coat to prevent heat from air from going into the animal’s body.

o Heat Exchangers:

 Ex: Oryx

 Has heat exchanger that changes the hot humid air

into water for consumption to cool off.

 It cools off the arterial blood going through the nose to keep the brain from getting too hot.

o Evaporative Cooling:

 To have water evaporate from your body in attempts to cool down.

 Panting (dogs).

 Trade-off between cooling & pH balance.

 Sweat glands (horses).

- On a hot summer day in the Australian outback, temperatures can reach 120 degrees F. Kangaroos lose excess body heat by doing what? Urinating on their legs – evaporation of the urine cools them off.

- How can the shrew maintain energy balance in the winter? It hibernates.

- The Study of Camels-

- Which posture best illustrates a camel at rest? They face the sun. It allows them to avoid exposing as much of their body surface.

o “The Ship of the Desert”:

 Knut Schmidt Nielsen tested the value of fur in camels by comparing the drinking rate of shaved and unshaved

animals.

 Conclusion: A shaved camel drinks 1.5 times more

water than an unshaved camel.

o Body Temperature in Camels:

 Considered endotherms.

 If a camel can’t drink water the temperature starts going up and doing about 6 or 7 degrees.

 The camels outer body temperature controls the amount of heat they absorb throughout the day.

 If a camel is high temperature, it will absorb more heat, making it work harder.

o A “Heat Budget” for the Camels:

 All heat in camels has to be dissipated by sweating.

 When it is water deprived, there is less water loss due to sweating.

o Kidney Function in Camels:

 Humans can make urine that is 3 times as concentrated as their blood.

 For camels, the urine/plasma ratio is what? 8

o Water Loss in Feces:

 Cows lose much more water in fecal matter than camels.  Almost half the water loss in camels.

o Dehydration: Human vs Camel

 Without water, a human in the desert will die in about 72 hours.

 Without water, a camel in the desert will die in about 2-3 weeks.

 Humans cannot tolerate water loss of more than 10% body weight in water.

 Camels can tolerate dehydration of 30-40% of body weight in water.

 When the camel drinks all of this water, what will happen to the blood cells as the plasma is diluted?

- How much water can a dehydrated camel drink in 5 minutes? 20 gallons.

- When the camel drinks all of this water, what will happen to the blood cells as the plasma is diluted? They shrink.

o Camel Red Blood Cells are Different:

 Human erythrocytes have no nucleus and can swell to 150% of normal volume in diluted plasma.

 Human’s red blood cells are circular.

 Camels are the only mammals with nucleated erythrocytes.  These cells can tolerate swelling to 240% of normal

volume.

 Camel RBCs are oval – this allows them to move through the blood vessels even when the blood is as thick as

pancake syrup.

Review Questions:

1. Most fungi are multicellular, and all fungi obtain nutrients by absorption.

a. True

b. False

2. In what ways are plants similar to algae?

a. Both have stiff stems that support the organism against gravity. b. Both have extensive root systems.

c. Both can do photosynthesis.

d. Both absorb nutrients from their environment through their entire body surface.

3. The lignin does what?