AP Biology Review

1. AP Biology Review Part 2

2. Prezygotic Barriers Postzygotic Barriers Habitat Isolation Temporal Isolation Behavioral Isolation Mating Mechanical Isolation Gametic Isolation Fertilization Reduced Hybrid viability Reduced Hybrid fertility Hybrid breakdown Reproductive BarriersLeading to Speciation

3. Lab 8Population Genetics and Evolution • You used the class as a sample group to look at the relationship between violating a Hardy-Weinberg condition and the changes in allele frequency. • Evolution here is defined as change in allelic frequency. • Hardy and Weinberg independently suggested a way to view evolution as changes in frequency of alleles in a population. • If certain conditions are met the allele and genotype frequencies will remain constant from generation to generation. They are: • Hardy-Weinberg Conditions • Large Population • Random Mating • No Mutation • No immigration or emigration • No selection

4. Hardy Weinbergp2 + 2pq + q2 = 1 • Total of all alleles p + q = 1 • p = A allele, q= a allele • p2 = AA homozygote (dominant) • pq = Aa heterozygote • q2 = aa homozygote ( recessive)

5. 4% of a sheep population has black wool, 96% white. If black wool is recessive what % of the population is heterozygous? • q2=.04 • q = √.04= .2 • 1-q = p • 1-.2= .8 • So q= .2 p=.8 • Substitute in 2pq • 2 (.8) (.2) = .32 or 32%

6. 4% of a sheep population has black wool, 96% white. If black wool is recessive what % of the population is heterozygous? • What % of the population is homozygous for white wool? • Substitute in for p2 • .82= .64 = 64%

7. A Few Genetics Terms • Autosomal traits- on non-sex chromosomes. • Sex-linked-genes on sex chromosome • sex-influenced- trait that appears differently in different sexes. On autosomes. • Sex-limited- characteristic appearing exclusively in one sex but whose gene is usually on an autosome. • Allele- form a trait can take. • Test cross-cross between an unknown genotype with a pure recessive for the trait (you always know the genotype from the phenotype). • Linked genes- on same chromosome. Won’t show classic mendelian ratio. • Crossing over- exchange between homologous chromosomes.

8. A Few more genetics terms Interaction between alleles: 1. Complete dominance- one allele appears phenotypically if present. 2. Incomplete dominance- The phenotype is intermediate between the dominant and recessive form, often due to ½ the product of the gene being produced. 3. Codominance- both alleles are fully expressed. 4. Multiple alleles- more than two alleles for a gene are found within the population (not within an individual). 5. Epistasis- one gene alters the effect on another gene. 6. Polygenic inheritance- many genes contribute to a phenotype. 7. Pleiotrophy- one gene can effect several phenotypic traits. 8. Environmental Influence- where the genotype and environment interact to determine the final phenotype.

9. Lab 7 Genetics of drosophila • You collected data from a fruit fly cross and analyzed results, • Drosophila have 4 pairs of chromosomes. • They show complete metamorphosis-egg, larvae, pupa, adults. • We looked at three types of crosses: • monohybrid-single contrasting pair of characteristics. • Dihybrids-two pairs of contrasting traits are considered simultaneously. • Sex-linked-mutant characteristic associated with the X chromosome. (white eyes). P=generation-pure parents F1= offspring of the P generation F2= offspring of the F1 generation

10. Lab 7 Genetics of drosophila-analysis • You counted e.g.: 67 red eyed flies 33 sepia flies • You would expect 3:1 ratio • 100 x ¾ = 75 (100 is the total number of flies) • 100 x ¼ = 25 • Chi- square- statistic used to see if your results are close enough to the expected results to be acceptable (significant) • X2 = ∑ (o-e)2o= observed e e= expected

11. Lab 7 Genetics of drosophila-analysis • X2= (67-75)2 +(33-25)2 = 3.41 75 25 Determine degrees of freedom Categories – 1 So 2-1 =1 If probability from the Chi-Square table is greater than your value you may accept your null hypothesis- “There is no statistically significant difference between your observed and expected data.”

12. Genetics question • A male fruit fly with red eyes and long wings was mated with a female with purple eyes and vestigial wings. All of the offspring in the F1generation had red eyes and long wings. • These F1 flies were test crossed with purple- eyed vestigial winged flies. Their offspring, the F2 generation, appeared as indicated below: • 125 red eyed, long winged • 124 purple eyed, vestigial winged • 18 purple eyed, long winged • 16 red eyed, vestigial winged

13. Genetics question • Knowns: Purple and vestigial are recessive- The F1 generation in a dihybrid cross shows the dominant trait because all of the organisms are hybrid. This was a special cross, it was a test cross in the F1 generation. • P cross was : p+p+v+v+ x ppvv • F1 generation was: p+pv+v (all red & long) • F1 test cross was p+pv+v x ppvv • p= purple v= vestigial • P+ = wild red v+ = wild long

14. Genetics question • F2 This cross does not show a typical 9:3:3:1 ratio of a dihybrid cross. Nor does it show the 1:1:1:1 ratio predicted from the Punnett Square (see above). The number of parental types seen in the F2 is large and indicates there is linkage of the two traits. They are on the same chromosome. Crossing over is responsible for the few recombinants.

15. Lab 4Plant Pigment and Photosynthesis • Part I: You separated plant pigments using chromatography. • Part II: You measured the rate of photosynthesis is isolated chloroplasts. • We used a blue dye, DPIP. When it is reduced (OIL RIG) it goes from blue to clear. • Electrons usually reduce NADP but reduce reduce DPIP instead in this setup. • You measured % transmittance of light using the cholorimeter. • You compared rate of • Unboiled in the dark (no light to excite the electrons) • Unboiled in the light • Boiled in the light ( chloroplast membranes were disrupted) • No Chloroplasts (Control)

16. Plants • Meristems-generate cells throughout the plants life. • Apical- extend roots and shoots (Primary Growth) • Lateral- add girth (secondary growth) • Transport tissues • Xylem-water and minerals • Phloem- carry sugar • Xylem is made of: • Tracheids- long thin • Vessel elements- wider, shorter • Both are dead at functional maturity • Movement of water from roots to leaves occurs by • Bulk-Flow- the movement of fluid driven by a pressure difference at opposite ends of a conduit. • The pressure difference is generated at the leaf end by transpirational pull ( lower pressure) at the leaf end. • Water pulled tight against the cell walls in the air spaces of the leaf cause the negative pressure which draws water up xylem.

17. PlantsAlternation of Generations Sporophyte Meiosis Zygote Sporophyte Generation (2n) Gametophyte Generation (n) Spore ♀ ♂ Fertilization Gametes Gametophyte

18. Major Branches of the Animal Kingdom Protostomes Mollusks, Annelids and Arthropods -Spiral Cleavage (cell divisions are along a diagonal line) -Determinate (cell fate is established early) Mouth forms from blastopore Schizocoelus (solid masses of mesoderm form coelom) Coelomate Have a true coelom- a body cavity lined with tissue of mesodermal origin Bilateria (bilateral symmetry) Cephalization 3 germ layers “Porifera” Sponges • Deuterostomes • Echinoderms and Chordates • -Radial Cleavage (cell divisions line up with the original cell divisions). • Indeterminate (allows for identical twins!) • anus forms from blastophore • Enterocoelous (outpockets of the archenteron form the coelom) Animals Pseudocoelomatea Rotifer-Coelom not completely lined by mesoderm Subkingdom Eumetazoa Radiata-”Cnidarians” Radial Symmetry Acoelomate No cavity between the gut and the body wall. Flatworm “Platyhelminthes”

19. Germ Layers and Their Derivatives There are three germ layers Ectoderm Endoderm Mesoderm

20. Germ Layers and Their Derivatives • Ectoderm • Epidermis and associated parts hair and nails • Lens and retina of the eye • Enamel of teeth • Nerve Cells • Medulla of the adrenal gland • Inner Ear

21. Germ Layers and Their Derivatives Endoderm • Inner lining of • Alimentary Canal • Lungs • Middle ear and eustachian tube • Gallbladder • Lung tubes • Urethra • Urinary Bladder • Bulk of • Thyroid • Parathyroids • Thymus (where immune cells mature) • Pancreas • Liver • Prostate Gland

22. Germ Layers and Their Derivatives • Mesoderm • Dermis of skin • Connective tissue • Cartilage • Bone • Lymphoid Tissue • Blood • Blood Vessels • Heart • Skeletal Muscles • Smooth Muscles • Kidneys • Testes • Ovary • Cortex of the Adrenal Gland A partial list for all germ layers.

23. Operons • In Prokaryotes • Region of a chromosome where a set of genes are transcribed at one time. • Allows all of the enzymes needed for a pathway to be present at once. • Two Types • Inducible are usually off but can be turned on. Like the lac operon. • Repressible are usually on but can be turned off. Like the trp operon.

24. Muscle Contraction • Sliding Filament Theory of Contraction • Thick (myosin) and thin (actin) myofilaments slide past one another shortening the muscle. • Control- Ca++ from the sarcoplasmic reticulum floods the muscle fiber when depolarized by a nervous impulse. The Ca++ moves the regulatory protein (tropomyosin) out of the way, by binding to troponin, allowing the cross bridges to form. • Functional unit: Sarcomere • Muscle fibers can be slow-twitch (slow to fatigue) or fast twitch ( quick source of power) • Cardiac muscle-interconnected • Smooth muscle-lack myofilament organization, but still use sliding filament theory.

25. Circulatory System • Open or closed (kept in vessels, all vertebrates). • No separate blood and lymph in the open system (like insects). Fluid is not called blood. It is hemolymph. • Blood vessels carry blood • Plasma-carries ions, proteins, hormones and metabolites. • Formed elements of the blood are erythrocytes (red blood cells)-carry O2 • Leukocytes (white blood cells)-fight infection. • Platelets-cell fragment function in blood clotting. • Blood Vessels • Arteries carry blood away from the heart, Veins to, • Lymphatic System returns interstitial fluid to the bloodstream. Moves through lymph nodes where many cells of the immune system search for antigens

26. Evolution of the Heart • Fish- • Single loop- to the gills, body, gills • Two chambered heart • Amphibians and reptiles • Double loop • Three chambered heart • Mammals and birds • Double loop • Four chambered heart • Better for active animals-keep oxygenated and deoxygenated blood separate,

27. Lab 11aAnimal Behavior • You looked at the response of organisms to environmental variables. • Ethology is animal behavior • Behavior may be • Learned • Innate (inherited) • Orientation Behaviors- help animal find the most favored environment. • Taxis-toward or away from a stimulus • Kinesis- random movement-not orienting toward a stimulus. • Agonistic behavior • Animal response that is aggressive or submissive. • Mating behavior • Complex behaviors that promote continuing the species.

28. Lab 11BReproductive Behavior in Fruit Flies • Mating follows a distinct behavioral pattern, a courtship pattern. • 1. Orientation • 2. Male Song (wing vibration) • 3. Licking of the female genitalia • 4. Attempted copulation • 5. Copulation • 6. Rejection (extrusion of ovipositor)

29. Blood Clotting • Vessel damaged, muscle cause constriction. • Platelets adhere, form a plug • Platelets pinch off from large cells in the bone marrow called megakaryocytes • Enzymatic reactions below are triggered by the platelets adhering. • Prothrombin is converted to thrombin • Fibrinogen is converted to fibrin which reinforces the clot the platelets are forming.