UNIT 3 HW QUESTIONS

CH.6 HW QUESTIONS 2 . A diploid cell has ________ the number of chromosomes as a haploid cell. one-fourth one-half twice four times 3 . An organism’s traits are determined by the specific combination of inherited ________. cells genes proteins chromatids 4 . Chromosomes are duplicated during what portion of the cell cycle? G1 phase S phase prophase prometaphase 5 . Separation of the sister chromatids is a characteristic of which stage of mitosis? prometaphase metaphase anaphase telophase 6 . The individual chromosomes become visible with a light microscope during which stage of mitosis? prophase prometaphase metaphase anaphase 7 . What is necessary for a cell to pass the G2 checkpoint? cell has reached a sufficient size an adequate stockpile of nucleotides accurate and complete DNA replication proper attachment of mitotic spindle fibers to kinetochores 8 . ________ are changes to the nucleotides in a segment of DNA that codes for a protein. Proto-oncogenes Tumor suppressor genes Gene mutations Negative regulators 9 . A gene that codes for a positive cell cycle regulator is called a(n) ________. kinase inhibitor tumor suppressor gene proto-oncogene oncogene 10 . Which eukaryotic cell-cycle event is missing in binary fission? cell growth DNA duplication mitosis cytokinesis 11 . FtsZ proteins direct the formation of a ________ that will eventually form the new cell walls of the daughter cells. contractile ring cell plate cytoskeleton septum CH.7 HW QUESTIONS 2 . What is a likely evolutionary advantage of sexual reproduction over asexual reproduction? sexual reproduction involves fewer steps less chance of using up the resources in a given environment sexual reproduction results in greater variation in the offspring sexual reproduction is more cost-effective 3 . Which type of life cycle has both a haploid and diploid multicellular stage? an asexual life cycle diploid-dominant haploid-dominant alternation of generations 4 . Which event leads to a diploid cell in a life cycle? meiosis fertilization alternation of generations mutation 5 . Meiosis produces ________ daughter cells. two haploid two diploid four haploid four diploid 6 . At which stage of meiosis are sister chromatids separated from each other? prophase I prophase II anaphase I anaphase II 7 . The part of meiosis that is similar to mitosis is ________. meiosis I anaphase I meiosis II interkinesis 8 . If a muscle cell of a typical organism has 32 chromosomes, how many chromosomes will be in a gamete of that same organism? 8 16 32 64 9 . The genotype XXY corresponds to: Klinefelter syndrome Turner syndrome Triplo-X Jacob syndrome 10 . Abnormalities in the number of X chromosomes tend to be milder than the same abnormalities in autosomes because of ________. deletions nonhomologous recombination synapsis X inactivation 11 . Aneuploidies are deleterious for the individual because of what phenomenon? nondisjunction gene dosage meiotic errors X inactivation Which of the following is NOT an advantage of sexually reproducing organisms: genetically unique offspring higher rate of adaptations faster reproduction higher chance for population survival Which of the following does NOT lead to variation among sexually produced offspring? replication of chromosomes during interphase random assortment of chromosomes during meiosis I crossing over between non-sister chromatid random fertilization When do cells become haploid during meiosis? meiosis I meiosis II mitosis interphase CH 8 HW QUESTIONS Imagine that you are performing a cross involving seed color in garden pea plants. What traits would you expect to observe in the F1 offspring if you cross true-breeding parents with green seeds and yellow seeds? Yellow seed color is dominant over green. only yellow-green seeds only yellow seeds 1:1 yellow seeds:green seeds 1:3 green seeds:yellow seeds 5 . Imagine that you are performing a cross involving seed texture in garden pea plants. You cross true-breeding round and wrinkled parents to obtain F1 offspring. Which of the following experimental results in terms of numbers of plants are closest to what you expect in the F2 progeny? 810 round seeds 810 wrinkled seeds 405:395 round seeds:wrinkled seeds 610:190 round seeds:wrinkled seeds 6 . The observable traits expressed by an organism are described as its ________. phenotype genotype alleles zygote 7 . A recessive trait will be observed in individuals that are ________ for that trait. heterozygous homozygous or heterozygous homozygous diploid 8 . What are the types of gametes that can be produced by an individual with the genotype AaBb? Aa, Bb AA, aa, BB, bb AB, Ab, aB, ab AB, ab 9 . What is the reason for doing a test cross? to identify heterozygous individuals with the dominant phenotype to determine which allele is dominant and which is recessive to identify homozygous recessive individuals in the F2 to determine if two genes assort independently 10 . If black and white true-breeding mice are mated and the result is all gray offspring, what inheritance pattern would this be indicative of? dominance codominance multiple alleles incomplete dominance 11 . The ABO blood groups in humans are expressed as the IA, IB, and i alleles. The IA allele encodes the A blood group antigen, IB encodes B, and i encodes O. Both A and B are dominant to O. If a heterozygous blood type A parent (IAi) and a heterozygous blood type B parent (IBi) mate, one quarter of their offspring are expected to have the AB blood type (IAIB) in which both antigens are expressed equally. Therefore, ABO blood groups are an example of: multiple alleles and incomplete dominance codominance and incomplete dominance incomplete dominance only multiple alleles and codominance 12 . In a cross between a homozygous red-eyed female fruit fly and a white-eyed male fruit fly, what is the expected outcome? all white-eyed male offspring all white-eyed female offspring all red-eyed offspring half white-eyed make offspring 13 . When a population has a gene with four alleles circulating, how many possible genotypes are there? 3 6 10 16 In pea plants, round peas (R) are dominant to wrinkled peas (r). You do a test cross between a pea plant with wrinkled peas (genotype rr) and a plant of unknown genotype that has round peas. You end up with three plants, all of which have round peas. From this data, can you tell if the parent plant is homozygous dominant or heterozygous? No, you cannot be sure if the plant is homozygous or heterozygous as the data is too small: by random chance all three may have acquired the dominant gene even if the parent was heterozygous and there was a chance to inherit the recessive allele. Yes, you know the parent is homozygous dominant because all three offspring inherited the dominant allele and the same size is large enough to draw conclusions Yes, you know the parent is heterozygous because if they were homozygous dominant they could not mate with the recessive parent. No you cannot be sure because there is a possibility the parent could be homozygous recessive but carrying the dominant allele.