BIO 1144 Week 2 Part 1
BIO 1144 Week 2 Part 1 Bio 1144
Popular in Biology II
Popular in Biology
This 6 page Class Notes was uploaded by Murry on Wednesday January 20, 2016. The Class Notes belongs to Bio 1144 at Mississippi State University taught by Thomas Holder in Spring 2015. Since its upload, it has received 88 views. For similar materials see Biology II in Biology at Mississippi State University.
Reviews for BIO 1144 Week 2 Part 1
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/20/16
Biology II Notes: Week 2 1. Kingdom Animalia • Huge group for sheer number of species, most of which are insects • Most complex Kingdom • Genetically similar to single ancestor • 35 Phylums • More similarity between animal genomes than all other Kingdoms • Characteristics: o Multicellular o No cell wall o Sexual reproduction: mobile, small sperm + large eggs o HOX genes – determine body axis during embryotic development o Most have nervous tissue o Cell junctions o Proteins bind cells (instead of carbohydrates) • Classification and Systematics o Looks at genetics, development, and morphology o Body Plans: 4 Main Features § Body Symmetry § Number of Tissues § Presence/Absence of True Body Cavity § Patterns of Embryotic Development o Looks at Parazoa (sponges) versus Eumetazoa (everything else) 1. Body Symmetry • Looks at the relative proportions that the body has, i.e. looking at the shape of the animal • Phylum Porifera (sponges) have are asymmetrical – have no body symmetry. This means they are simple animals. • Eumetazoas have symmetry. • Radial Symmetry: a plane/line passes through the central axis and produces equal/mirror images (example: sea star) • Bilateral Symmetry: only 1 line produces equal images; typically goes with distinct head and tail (example: humans) 2. Tissue Layers (aka: germ layers) • How many layers are present? • Tissue – an aggregation of functionally similar cells into a larger unit (tissue à organ à organ system) • Parazoa (sponges) have no tissues or organs. • Eumetazoa have 1 or more tissue types. The higher the number of tissue layers, the more complex the organism. • 2 Types of tissue classifications: o Diploblastic § Usually has radial symmetry § Has 2 tissue layers called the endoderm (inner layer) and ectoderm (outer layer) § Usually simpler animals o Triploblastic § Usually has bilateral symmetry § Has 3 tissue layers: endoderm, ectoderm, and mesoderm (the middle layer) • Tissue layers develop in early phase called gastrulation 3. Body Cavity • Only bilaterally symmetrical animals have a body cavity (therefore, sponges lack a body cavity) • Coelom: a fluid-filled body cavity in animals • A “true” coelom is a cavity that is completely lined with mesoderm or mesoderm derived tissues. This is only found in the most advanced animals. • 3 Patterns: o Acoelomate: “without coelom” § No coelom § Lacks space inside the organism § No mesoderm or mesoderm derived tissues § Example: Flatworms (Phylum Platyhelminthes) o Pseudo-coelomate: “false coelom” § Cavity present and well-developed, but not completely lined with mesoderm or mesoderm derived tissues § More complex than Acoelomate § Example: Roundworm (Phylum Nematoda) o Eucoelomate: “true coelom” § Most complex/advanced animals § Majority of animals have true body cavities § Completely lined with mesoderm or mesoderm derived tissues § Example: Earthworm (Phylum Annelida) 4. Embryotic Development • Complexity of embryotic development relates to how advanced the animal is • Cleavage: after the egg is fertilized, cells divide into many smaller cells but the cell does not increase in size • 2 Mechanisms of Development: Protostomes or Deuterostomes o Protostomes § Proto means “first” § Blastopore: the 1 opening to develop § The first opening to developed in a protostome becomes the mouth o Deuterostomes § Deutero means “second” § The first opening to be developed in a deuterostome becomes the anus § The second opening developed becomes the mouth § Only 2 phylums: Echinodermata and Chordata • Other Methods of Animalia Classification: o Skeleton Study § Skeletons fossilize easily § Classify by exoskeleton vs. endoskeleton (or invertebrates vs. vertebrates) o Notochord § A cartilaginous skeletal rod supporting the body in all embryonic and some adult chordate animals. § Only found in Phylum Chordata § Very advanced structure § Can have this feature in a single stage of life (baby, adolescent, adult, etc.) or throughout all stages of life o Metamerism (aka: Segmentation) § The repetition of body parts § Considered an advanced feature § Example: ribs, joints o Cephalization § Distinct “head end” with a brain § Localization of sensory structures Molecular Views of Animal Diversity • Molecular diversity is a new classification technique that uses DNA, ribosomal RNA, and mitochondrial DNA. • Advantages: o DNA is testable o Easy to compare/contrast gene sequences • Similarities between Traditional (everything discussed above) and Molecular Classification: o All animals share common ancestor: Protist o There is a true split between sponges and all other animals. o There is a true split between radial and bilateral symmetry. o Echinodermata and Chordata are closely related • Differences in Molecular View: o Protostomes separated into 2 groups: early organisms and late organism o Determines that body cavity is not usable for classification Invertebrates • “lacking backbone” • fossils around 1.2 billion years old • make up 95% of animal species Phylum Porifera (sponges) • Lack tissues • Multicellular • Have different cell types with different functions for each type • 8,000+ species, most of which are marine creatures (animals that live in salt water) • Pores filter water and nutrients • Reproduce by Hermaphroditism – the same organism has both male and female sex organs, aka: it reproduces with itself • Some reproduce sexually, other asexually Phylum Cnidaria (jellyfish, coral, anemones) and Phylum Ctenophora (comb jellies) • More closely related than any other group • 9,000 species of Cnidaria; 100 species of Ctenophora • Not very complex creatures • Mostly marine animals (there are freshwater jellies) • Mesoglea – gelatinous coating outside the body for protection and insulation • Nerve Net – not a nervous system, but rather an impulse network that sends signals through the body (lacks a brain) • Protostomes (only 1 body opening) • Gastrovascular Cavity – body compartment that is pushed out of opening to absorb food and release waste Phylum Platyhelminthes • Include flatworms, flukes, and tapeworms • Most are parasites • 20,000 species • Triploblastic (3 tissue layers) • Protostomes – 1opening and a gastrovascular cavity • Simple, yet developed organs and organ systems • Enhanced Nerve Net • 2 cerebral ganglia (mass of nervous tissue that send impulses, but not a brain) • Hermaphrodites – does not allow for genetic variation Phylum Rotifera (rotifers) • Move by swimming and spinning • Microscopic or near microscopic animals • One end has a corona (crown shape) • 2,000 species • Freshwater creatures • Have a simple brain • Psuedo-coelomate • Alimentary canal – digestive tube • Triploblastic; Protostomes • Both asexual and sexual reproduction; sexual reproduction by Parthenogenesis – the egg develops without fertilization/sperm Phylum Mollesea • Snails, slugs, oysters, squids, barnacles, clams, etc. • 106,000 species • Protostomes and Eucoelomates • Generally have 3 body parts: Foot (part in contact with the ground for movement), one or more Visceral Mass(s) (internal organs), and a Mantle (something housed inside a shell) Phylum Annelida • Segmented or ringed worms • 15,000 species • Eucoelomate; Protostomes • Enhanced digestive and nervous systems • Reproduce asexually or sexually (Hermaphrodites) Phylum Nematoda (roundworms) • Primarily live in the soil, but also found in digestive tract of larger animals • 20,000 species • Pseudo-coelomate • Cuticle – rubbery outing coating that is shed in order to grow; also provides protection in digestive tract • Usually parasites • Reproduce mostly sexually • Protostomes • Complete digestive tract Phylum Arthropoda • Includes all insects plus crustaceans and spiders • 1.75 – 2 million species • Have segmented appendages • Exoskeleton – hardened cuticle made from protein and chitin • Some can shed their outer skin / skeleton • Protostomes; Eucoelomate • Enhanced brain and nervous system and enhanced digestive tract • Social insects with a true animal society tend to have the most complex nervous system which allows for advanced communication. Phylum Echinodermate • Sea stars, urchins, etc. • Deuterostomes • 7,500 species • No brain; simple nervous system • Reproduces sexually • Autonomy – breaking off of body parts; used as a defense mechanism (Example: a predator goes after the animal. The animal breaks off an appendage. The predator eats/is distracted by the separated body part while the rest of the animal escapes.) • Endoskeleton – composed of a series of plates; allows for the autonomy Phylum Chordata • Deuterostomes • Endoskeleton • Mostly vertebrates (a few can be invertebrate)
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'