BSC 2010C SI EXAM 3 REVIEW REVIEW SESSION AT: Wednesday, 12 2 PM In CB2 Room 105

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1 BSC 2010C SI EXAM 3 REVIEW REVIEW SESSION AT: Wednesday, 12 2 PM In CB2 Room 105 Ch. 10 1) Where does the light cycle happen? Thylakoid membrane 2) Where does the calvin cycle happen? Stroma Ch. 12 3) How many parents are required for sexual reproduction? 2 4) How many parents are required for asexual reproduction? 1 5) What is binary fission? Cells copy themselves. Happens in prokaryotes. 6) In cell division, 1 cell divides to form 2 cells. 7) What does the DNA in bacteria look like and how long can it be? Circular, can be up to 500x the cell length

2 8) Give the steps to binary fission. Before cell division, the genome gets copied. Copies attach to adjacent parts of membrane. Cell elongates, and the new plasma membrane separates 2 genomes Plasma membrane pinches through the cell. 9) How many genes does your average somatic cell contain? 30,000 35,000 Genes 10) What structure are genes organized into? Chromosome 11) When are chromosomes visible? Become visible just prior to cell division and they remain visible through cell division (PMAT) 12) Body cells are also called Somatic cells. 13) How many chromosomes do somatic cells have? Does this make them haploid or diploid? 46 chromosomes. Diploid 14) Sex cells are also known as Gametes. 15) How many chromosomes do sex cells have? Does this make them haploid or diploid? 23 chromosomes. Haploid. 16) What does a replicated chromosome look like? How many chromatids in a replicated chromosome? Are sister chromatids always identical? It looks like an X. 2 sister chromatids. They are not always identical. In

3 mitosis they are always identical, but in meiosis they experience crossing over, making some not identical. 17) What does an unreplicated chromosome look like? How many chromatids in an unreplicated chromosome? A stick. 1 chromatid. 18) What is at the center of a chromosome? (the point where sister chromatids can attach) Centromere 19) How many chromosomes do humans have total? 46 20) How many pairs of chromosomes are autosomal? 22 pairs. So 44 chromosomes are autosomal. 21) How many pairs of chromosomes are sex chromosomes? What are they? 1 pair. 23 rd pair. 2 chromosomes total. X & Y chromosomes. 22) Which parts of the cell cycle fall under interphase? G1, S, G2 23) In a cell that will undergo mitosis, what is the M phase of the cell cycle? Mitotic phase (PMAT) 24) What are the phases of mitosis? Prophase, Metaphase, Anaphase, Telophase & Cytokinesis(Separation of cytoplasm)

4 25) What percentage of time is spent on interphase during the cell cycle? 90% of the time 26) What happens in the G 1 phase? Cell grows and increases supply of proteins and organelles. 27) What happens during the S phase? DNA is copied/replicated (AKA DNA synthesis) for future divisions. 28) During the S phase, are the chromosomes visible? NO, only during the Cell division 29) What happens in the G 2 phase of the cell cycle? More growth. Cell prepares for more division and increases the supply of proteins necessary for division. Checks DNA for damage (checkpoint). 30) What is the G 0 phase? Cell stops going through the cycle, and will not divide unless cell is good to move on. If the cell is not okay, then it will kill itself on purpose (apoptosis= programmed cell death) 31) Can cells go in and out of G 0 from other cell cycle phases? YEAH 32) (T/F) All cells in the same tissue are in the same phase of the cell cycle at all times. FALSE 33) What is kinase? An enzyme that catalyzes the transfer of a phosphate group from ATP to another molecule. 34) What are cyclins? Special chemicals that help the cell cycle keep moving

5 35) What is Cdk? Cyclin Dependent kinase 36) What is MPF? co-chemical attached to Cdk 37) What do Cdk and MPF do? What happens when they are high? Stimulate transition to cell division. The cell will divide when the levels are high. 38) What two steps is the M (mitotic) phase divided into? Mitosis (nuclear division) Cytokinesis (Cytoplasm division) 39) A cell that will undergo mitosis is Diploid. 40) After mitosis, are the daughter cells different from or identical to the parent cells? They are identical to the parent cell. 41) After mitosis are the daughter cells haploid or diploid? Diploid 42) In mitosis, what happens during prophase? Nuclear membrane breaks down, spindle forms, chromatin condenses into chromosomes and that signals the end of prophase. 43) In mitosis, what happens during metaphase? Chromosomes align single file with centromeres in cell equator. 44) In mitosis, what happens during anaphase? Sister chromatids get separated by spindle fibers and migrate to the poles. (At this point the chromosomes become un-replicated) 45) In mitosis, what happens during telophase? Opposite of prophase

6 46) What is cytokinesis? Division of cytoplasm 47) What is the cleavage furrow? During cytokinesis, it is the pinched looking top of the cell. 48) In normal cells, how many times does cell division occur before cell death? times 49) What happens to telomeres with each division? They shorten with each division 50) What is density dependent inhibition? When a single layer of cells is formed and cells are touching, the division stops. 51) What are the three major checkpoints in the cell cycle? G1, G2, Mitotic phase 52) What allows the cell cycle to continue at each of these checkpoints? Release of growth factor/chemical signals 53) What does it mean for cancer to metastasize? How is this allowed? To spread because it is not being affected by the checkpoints. 54) Does a malignant tumor metastasize? YES 55) What does benign mean? No matastasis 56) When do benign tumors become malignant? When the cancerous cells from the tumor mass spread to new sites and continue to proliferate (Reproduce) 57) What is this movement mediated by? Blood or lymph systems

7 58) What does telomerase do? It keeps telomeres lengthened. 59) What are two common treatments for cancer? Describe what they do. Chemotherapy: disrupts cell division Radiation: Disrupts normal process of cell division, and cancer cells are more susceptible. 60) Which two ways do cells die? What does each mean? Apoptosis: Programmed cell death, often good. Necrosis: die from damage, poison, starvation, hypoxia (Too little oxygen), ATP depletion 61) What is an example of apoptosis? Sunburned cells 62) Can cancer cells carry out apoptosis? No, that s why they spread uncontrollably. CH ) What is a homologous pair of chromosomes? 2 chromosomes that share shape, loci, and carry genes containing the same traits. 64) What is the homologous pair of chromosomes for females? XX 65) What is the pair of chromosomes for males? XY 66) What is a locus? Position of a gene on a chromosome. Locus is singular. Loci is plural.

8 67) How is a zygote formed? Fusion of haploid gametes at fertilization. (sperms meets egg, it becomes a zygote) 68) A cell that is about to go through meiosis has how many chromosomes? That makes it haploid or diploid? Are the chromosomes replicated or unreplicated? 46, Diploid, Replicated so they are shaped like X s 69) After meiosis I, how many chromosomes does that cell have? That makes it haploid or diploid? Are the chromosomes replicated or unreplicated? 23, haploid, replicated so they are shaped like X s 70) After meiosis II, how many chromosomes does that cell have? That makes it haploid or diploid? Are the chromosomes replicated or unreplicated? 23, haploid, unreplicated so they are shaped like sticks. 71) How many chromatids does a cell have right before meiosis I? 92 chromatids 72) How many chromatids does a cell have right after meiosis I? 46 chromatids 73) How many chromatids does a cell have right after meiosis II? 23 chromatids 74) Meiosis occurs only in Diploid cells destined to become Haploid/gametes. 75) For every one cell that undergoes both phases of meiosis (I and II), how many daughter cells are there? 4 daughter cells 76) In meiosis I, what happens during prophase I? Synapse (pairing of homologues), chiastmata (Crossing over), DNA condenses into chromosomes, nuclear membrane breaks down, spindle apparatus. 77) What happens during metaphase I? homologues align in cell center

9 78) What happens during anaphase I? Homologues get pulled apart to different poles of the cell. (XX) (--X X--) 79) What happens during telophase I? End of division and we get two haploid cells with 23 replicated chromosomes each. 80) What happens between meiosis I and meiosis II? Short interphase period, BUT NO S PHASE HAPPENS. SO DNA DOES NOT GET REPLICATED. 81) In meiosis II, what happens during prophase II? Nuclear membrane breakdown DNA Condenses Spindle forms 82) What happens during metaphase II? Chromosomes aligned at cell center. 83) What happens during anaphase II? Sister chromatids pulled apart to a different pole of the cell. The chromosomes are now un-replicated. (X) (--I I--) 84) What happens during telophase II? End of division & you have 4 haploid cells with un-replicated chromosomes. 85) (T/F) Meiosis II very closely resembles mitosis. True, the only difference is that it goes from haploid to haploid 86) Why do cells only run through meiosis I and II one time? Because they are now haploid after meiosis II and haploid cells cannot undergo meiosis.

10 87) What is the independent assortment of chromosomes? Mom & dad chromosomes can line up either on the left or right side of each. This is a random process and created more varied offspring. ( X X) ( XX ) ( X X) ( XX ) 88) Why do the homologous pairs of chromosomes undergo the process of crossing over? It creates genetic variation Ch ) Write some information about Gregor Mendel and his study of genetics. university trained in experimental technique Had a background in math and understood probabilities Worked w/ peas WHY? >They have short life spans >The have numerous and distinctive characteristics >Their mating can be controlled 90) What does monohybrid mean? Working with one trait (gene) 91) What does dihybrid mean? Working with 2 traits (genes) at the same time. Ex: Working with hair color and eye color at the same time BbHh x BBhh 92) What is the P generation? Parent generation

11 93) What is the F 1 generation? Offspring of P generation 94) What is the F 2 generation? Offspring of TWO F1 Generation organisms 95) What is a gene? List a few exmples. Genes are traits Ex: Hair color, Eye color 96) What is an allele? List some examples. Variations of a gene (Trait) Ex: Blue eyes, Brown eyes, Black hair 97) What is a phenotype? Physical characteristic EX: Blue eyes, Brown eyes 98) What is a genotype? Genetic make up. EX: BB, Bb, bb 99) What does homozygous mean? 2 of the same alleles Ex: BB or bb 100) What are the two types of homozygous. Homo dominant: BB Homo recessive: bb 101) What does heterozygous mean? 2 different alleles Ex: Bb 102) What does hemizygous mean? A gene is active and present in only 1 chromosome Sex-linked chromosomes (X & Y) X chromosome carries more genes than Y chromosome

12 103) What is the law of segregation of alleles? Allele for a given trait located on each homologous chromosome separates during meiosis. 104) What is a test cross? Crossing unknown genotype with a recessive phenotype. 105) What is the rule of multiplication? probability if 2 events happening together is the PRODUCT of the probability of each event happening by itself. Ex: Toss a coin. Prob. of heads: ½ Prob. of tails: ½ Probability of head and then a tail is what?: ½ x ½ = ¼ 106) List all the types of non-mendelian inheritance and list an example of each. Incomplete dominance: 1 allele not completely dominant. Ex: Color in snapdragon plants Multiple alleles: More than 2 alleles. Ex: Blood Types (ABO) Co-dominance: Neither allele is dominant over the other. EX: A & B blood types. AO = blood type A so A is dominant over O. When you have AB= blood type is AB because neither is dominant. Pleitropy: 1 gene can affect multiple phenotypes. EX: Sickle cell anemia, Marfan s Syndrome Epistasis: Expression of one gene interferes with the expression of another. EX: Coat color in mice Polygenic inheritance: 1 characteristic is influenced by many genes. EX: Height 107) How many genotypes are there for blood type? List them. 6 genotypes: AA, AO = Type A BB, BO = Type B OO = Type O AB = Type AB 108) How many phenotypes are there for blood type? List them. 4. Type A, Type B, Type O, Type AB 109) List three autosomal recessive disorders. Cystic fibrosis, Sickle cell anemia, Tay-sac s

13 110) List three autosomal dominant disorders. Huntington s disease, achondroplasia, neurofibromatosis, Munchkin(in cats) Ch ) Do sex-linked genes follow simple Mendelian inheritance? NO 112) In humans, most sex-linked characteristics are due to genes on the X chromosome. 113) What are some examples of some sex-linked characteristics? color blindness, muscular dystrophy, hemophilia 114) How many functional X chromosomes does a normal female have? 1 because the other one turns inactive. 115) What happens to the inactive X chromosome in a female? Turns into a Barr body 116) What does a barr body look like? A dark spot in the nucleus 117) What is aneuploidy? abnormal number of chromosomes 118) What is nondisjunction? when 2 chromosomes get pulled into the same cell in anaphase I rather than being pulled apart 119) What is trisomy 21? Down s syndrome. Someone affected by this has 3 chromosomes in the 21 st pair 120) What is Klinefelter s Syndrome? Male with multiple X chromosomes Ex: XXY or XXXY 121) Is having an X and two Ys lethal? No, XYY is not lethal and actually doesn t affect you very much.

14 122) What is polyploidy? More than two complete sets of chromosomes. 123) What are the four structural rearrangements that can occur from breakage of a chromosome? Deletion, Duplication, Translocation, Inversion 124) What is deletion? Removes a chromosomal segment 125) What is duplication? Repeat a segment of a chromosome 126) What is translocation? Moves a segment from one chromosome to another chromosome that is not homologous to the original one 127) What is inversion? A chromosome segment gets reversed 128) Chronic Myelogenous leukemia is associated with which structural rearrangement? Translocation 129) What is genomic imprinting? Phenotypic effect of some genes depends on which parent it was inherited from. Individuals imprint chromosomes in gamete cells during meiosis. Affects expression in offspring. 130) What is fragile X syndrome? Most common cause of developmental delay Tip portion of X hangs by a thin piece of DNA 1:1,500 males IN NORMAL X: in the 5 untranslated region first exon CGG triplet repeated 30 times. IN FRAGIL X: CGG repeated hundreds to thousands of times, which creates a fragile site.