Biology Exam I Material -Study Guide
Biology Exam I Material -Study Guide Bio 111 - Fundamentals of Biology II
Popular in Biology
Popular in Biology
verified elite notetaker
One Day of Notes
verified elite notetaker
verified elite notetaker
verified elite notetaker
One Day of Notes
verified elite notetaker
verified elite notetaker
This 12 page Study Guide was uploaded by valerie zaid on Saturday April 30, 2016. The Study Guide belongs to Bio 111 - Fundamentals of Biology II at Purdue University taught by Athena Anderson in Spring 2016. Since its upload, it has received 15 views. For similar materials see Biology in Biology at Purdue University.
Reviews for Biology Exam I Material -Study Guide
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: 04/30/16
Biology Exam 1 Study Guide Zygote (1 cell) Adult (10’s of trillions) B. subtilis spore (1.2um) Bacterial colony (10’s of billions) How do organisms repair themselves? Cell division What happens if cell division is uncontrolled? A tumor Cell division Required 3 things: o Replication of genetic material o Accurate segregation of genetic material o Division of cytoplasm Binary fission (simplest type of cell division) o Asexual reproduction in prokaryotes and single-celled eukaryotes o Duplicate and segregate genetic material o Origin of replication/ bidirectional: terminus o Active process- controlled by cells o Allows regeneration in some starfish Chromosomes o Centromere: visible constriction Holds (sisters) chromatids together Consists of repeated short DNA sequences o Kinetochore: proteins at centromere o Telomeres: ends of chromosomes, also specialized structures Replicated by special protein: telomerase o You have two homologs for each chromosome (diploid=2n) o Homologous chromosomes come together during meiosis to form a tetrad (4 chromatids total); process called synapsis o Centromere holds chromatids together o Kinetochore connects centromere with microtubule spindle fibers o Corona aids attachment of kinetochore to microtubules Problems that a cell must solve in order to replicate correctly Chromosome compaction o Chromosomes are too long to fit into cell straight, must fold Complex with proteins Supercoiled by topoisomerase o Before the cell ca actually divide o Chromosome is also attached to plasma membrane Eukaryotic Cell Cycle 5 parts: o G1: pre-replication o S: DNA synthesis o G2: post-replication o M: mitosis o Cytokinesis: division of cytoplasm into two cells Two irreversible steps o When it starts: The commitment to divide at all o Anaphase: the separation of chromosomes during anaphase Once chromatids are no longer together they must segregate into two new cells Uncontrolled cell division o Division with incompletely replicated DNA would be lethal o Division with damaged DNA would be lethal or lead to cancer o Cell controls cycle with checkpoints Start or restriction point G2/M transition Anaphase o Fail to “pass test”: cycle halted Mitosis o Segregate chromosomes 4 stages: (PMAT) o Prophase o Metaphase o Anaphase o Telophase Prophase: o Chromosomes condense o Nuclear membrane breaks down o Spindle is formed o Chromosomes attach to spindle Metaphase: o Chromosomes move to the metaphase plate o Chromatids are still attached at the centromeres o Centromeres attached to opposite poles by microtubules o Chromosomes pulled towards opposite poles Anaphase: o Centromeres “divide”, chromatids separate (now called chromosomes) o Chromosomes are pulled to opposite poles Telophase: o Chromosomes decondense o Nuclear membrane reforms Cytokenisis: o Dividing one cell into two o Divides cytoplasmic contents o Animal: uses a contractile ring o Plants: cell plate forms between cells Meiosis Reproduction o Asexual: offspring are clones of one parent o Sexual: offspring are unique, different from both parents Asexual Reproduction (more common in plants and protists) Many types: 1. Binary fission 2. Budding 3. Runners 4. Rhizomes Sexual Reproduction o Gametes (sperm, eggs): sex cells produced in gonads of parents, designed to carry half of parent’s genes o Somatic cells: not involved in producing gametes (heart, skin etc) Genes: segment of DNA that codes for a trait (ex. Eye color) Allele: version of a gene (ex. Brown eyes) In humans, most genes have two alleles; one from the mother and one from the father Homologous chromosomes: genes coding for the same characteristics, in the same locations Karyotype: picture of chromosomes (#23 sex chromosomes) Ploidy Denotes number of copies of genes/chromosomes in organism, abbreviated as a number and the letter “n” o Haploid: 1n (1 copy) o Diploid: 2n (2 copies)(humans are 2n) Meiosis o Cells produced are not identical to parent cell (unlike in mitosis) o Add genetic variation to population o This is the variation that allows natural selection and evolutions to happen Gametogenesis: gamete formation o Two successive cell divisions o No DNA replication Meiosis I: o Purpose: increase genetic variation o Phases: Interphase Prophase I Metaphase I Anaphase I Telophase I Cytokinesis Interphase before Meiosis I o All DNA is copied so tetrads can form later o Still considered 2n Prophase I o Chromosomes visible o Nuclear membrane disintegrating o Tetrads form o Synaptonemal complex holds homologs together (synapsis) o Crossing over occurs at chiasmata Crossing over: homologos exchange sections between non-sister chromatids and form new combinations of genes Metaphase I o Microtubules move tetrads to metaphase plate o One chromosome in each tetrad is facing one pole Anaphase I o Pull tetrads apart o One chromosome goes to each pole Telophase I and Cytokenisis(actual moment when splitting) o Chromosomes are moving to the poles o 2 chromatids each chromosome o nuclear envelope reforms o 2 haploid cells result after cytokenisis o chromosomes unwind into chromatin during cytokenisis Meiosis II: o same steps as mitosis, but chromosomes have been through crossing over o end product is 4 haploid cells Prophase II o chromatin re-condenses into chromosomes o nuclear envelope starts to break down o spindle fibers start to form o lack of tetras and evidence of crossing over Metaphase II o chromosomes aligned on metaphase plate o chromatid faces opposite poles o spindle fibers attached at centromere o lack of tetrads and evidence of crossing over Anaphase II o spindle fibers pulling chromatids apart towards opposite poles o single chromatid and evidence of crossing over Telophase II and Cytokenisis o nuclear envelope forms o chromatid starts to decondense into chromatin o each daughter cell splits into two, being haploid o final result of meiosis is 4 haploid cells Spermatogenesis: formation of sperm, occurs in testes Oogenesis: formation of ova (eggs) o Every division results in a tiny cell called polar body o Only one egg is actually made Mendelian Genetics o Blending inheritance (Before Mendel’s work): offspring had intermediate characteristic compared to parents o Mendel showed the importance of quantifying experiments to discover how genetics work o Several terms: Genotype: alleles carried by individual Phenotype: appearance of individual Hybrid: offspring of true-breeding parents with different traits for same character Cross: sexual reproduction between different individuals Character: a feature, like hair color or plant height Trait: genotype or phenotype of an individual for a given character (red hair) o True breeding: individuals always produce offspring that resemble themselves when self-fertilized. Only applies to plants o P0 = parental generation o F1= first offspring generation o F2= offspring of a cross between two F1 individuals o Recessive trait: masked by dominant trait; “r” o Dominant trait: masks recessive traits; “R” o Offspring only gets one set of chromosomes from each parent o Law of segregation: two alleles for a heritable character separate from each other during gamete formation, ending up in different gametes o Genotype determines phenotype: RR dominant phenotype (homozygous) Rr dominant phenotype (heterozygous) Rr recessive phenotype (homozygous) o Punnet squares used to show possible genotypes and phenotypes of offspring o Monohybrid cross: only looking a one trait in a cross o Dihybrid cross: look at two traits in a cross at once o Law of independent assortment: two or more genes are sorted into gametes independently of each other. (By using laws of probability we can predict outcomes probabilistically) o Incomplete dominance: offspring have intermediate traits o Dominance: dominant allele prevents expression of recessive allele in offspring o Codominance: two alleles have equal contribution to offspring phenotype Sickle-cell disease: genetic inherited, cells cannot carry oxygen as well as normal cells (SS) 1/10 african americans have AS genotype o multiple alleles: one gene controls a character, but has more than 2 alleles o Pleiotropy: one gene has multiple phenotypic effects o Epistasis: phenotypic expression of one gene affects that of another gene at different locus o Modifiers: genes that affect the degree to which another gene is expressed o Polygenic inheritance: two or more genes affect the same phenotypic character (ex. Human skin and eye color) Non-Mendelian Genetics o Sex-linked genes: those located on either sex chromosomes X-linked genes are responsible fore several conditions: Color-blindness in men Duschene muscular dystrophy in men: causes progressive weakness of muscles Hemophilia: decreases blood ability to clot o Linkage: autosomal genes are frequently inherited together during meiosis of their loci are close together o As distance between genes increases, recombination frequency increases o Abnormal chromosome numbers: nondisjunction during meiosis results in gametes that are diploid for some genes o Polyploidy: individual has more than diploid chromosomes sets o Pedigree analysis Graphical method summarizes family data Suggest models of inheritance for diseases Can be used for genetic mapping Use to determine whether a couple is at high risk for passing on a genetic disorder to a child Physiology and Homeostasis o Multicellular animals have an organization of strictures: Cells organized into tissues, organized into organs, organized into organ systems o Homeostasis: ability to maintain a constant internal environment despite fluctuating external environment; requires internal communication about the state of the organism o Concentration of important molecules in body fluids have set points Signaling Molecules o Autocrine: same cell type sends and receives signal o Paracrine: one cell type sends signal, other cell type receives o Local signaling molecules: neurotransmitters, histamines etc o Distant signaling molecules: hormones, growth factors Endocrine System o Regulates body’s “set points” o Triggers important physiological events o Facilitates cell to cell communication Hormone: a chemical secreted by an endocrine gland/organ into the blood for transport Endocrine gland: a ductless gland or single cell that secretes a hormone, which travels through blood; targets the cell or organs that have receptors for the hormone o Hypothalamus Maintains homeostasis by controlling the autonomic nervous system Releases neurotransmitters, hormones that regulate anterior pituitary and hormones that are stored in posterior pituitary for later release o Pituitary gland Posterior: receives neurohormones from hypothalamus and stores them until needed Anterior: receives hormonal signals from hypothalamus Classes of hormones: 1. Steroids 2. Peptide 3. Protein 4. Glycoprotein Negative feedback loops response to altered set point stops its own production: self-limiting o o After eating: 1. Stimulating insulin production by pancreas 2. Insulin lowers blood glucose 3. Insulin production stops 4. Overall result: blood sugar drops o Between meals: 1. Blood glucose falls, stimulating glucagon production 2. Glucagon raises blood glucose 3. Glucagon production stops 4. Overall result: blood glucose rises Diabetes: a disease that disrupts insulin/glucose regulation o Type 1: genetic, pancreas doesn’t produce enough insulin, treated with insulin injection, 10% o Type 2: usually acquired through lifestyle, pancreas can’t make enough insulin to keep blood glucose down, 90% o Type 2 on rise in children, usually attributed to diet and inactivity o Children with higher risk: African American, Hispanic, Asian, Native American o Associated risks: Heart disease Nerve, eye, kidney, foot damage Skin conditions Hearing impairment Alzheimer’s disease Fight or Flight response 1. Brain tells hypothalamus a threat is perceived 2. Hypothalamus signals pituitary to release ACTH 3. ACTH signals adrenal gland to release epinephrine and cortisol 4. Together, they increase blood pressure, sugar, and gluconeogenesis 5. Result is burst of energy to muscles, to prepare body to fight or flee o Noticeable effects: Pupils dilate Tunnel vision Hearing loss Digestion slows Shaking Blood flow diverted from extremities to muscles Steroids are made from cholesterol Effects of chronic stress o “good stress” is called eustress; keeps you alert and engaged in activities o “high stress” is called distress; keeps the body in “fight or flight” mode o Thyroid Controls metabolism, affects temperature, heart rate, growth Produces two hormones: triiodothyronine (T3) and Thyroxine(T4) Hypothyroidism: thyroid doesn’t produce enough T3 or T4 Goiter: enlarged thyroid gland, can be caused by a numerous conditions: iodine deficiency, cancer, nodules, pregnancy, inflammation etc Most common in developing countries, where iodine deficiency more likely o Thymus Active during youth, starts to atrophy at puberty-turns to fat Produces T-cells and thymosin, which causes maturation of t-cells Sjorgens Syndrome o Autoimmune disease, thought to come from T-cells that aren’t “trained” in thymus long enough o Causes symptoms like fatigue and drying of body’s moisture o Adrenal glands Produce many hormones: Estrogen and progesterone (female sex hormones) Cortisol and cortisone (anti-inflammatory) Epinephrine and norepinephrine (increase heart rate, sugar metabolism etc) Dopamine (neurotransmitter gives happy feeling from award-seeking behavior) Addison’s disease o Adrenal glands produce insufficient cortisol o Causes fatigue, weight loss, vomiting, depression etc o Pancreas Produces insulin and glucagon to regulate blood glucose Also produces enzymes that help with digestion o Testes/Ovaries Testes: mal gonads, produce testosterone and other androgens Ovaries: female gonads, produce estrogen and progesterone Up to 6 weeks post-fertilization males and females are indistinguishable gonadally Acromelagy o Caused by overproduction of GH from pituitary o Causes elongation of legs, feet, arms, hands, jaw o Associated risks: type 2 diabetes, high blood pressure, arthritis, cardiovascular disease Cushing’s Syndrome o Most often caused by overuse of glucocorticosteroid medication, which mimics cortisol o Tumors most common natural cause Hormones and development o Hormones control normal development in all complex animals o Molting in insects is caused by hormone ecdysone, a steroid secreted by glands in the thorax
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'