Chapter 16

1. Chapter 16 To the winner… 15% bonus added to their test

2. What personal characteristics and events in Gregor Mendel's life significantly contributed to his ultimate contribution to the study of inheritance?  • His training in physics and mathematics at the University of Vienna. • He failed his physics exam. • He failed his natural history exam. • He got his teaching license at the age of 21. • He got a job as a substitute teacher and enjoyed it. :01

3. Mating a purebred Labrador retriever to a purebred poodle to produce "Labradoodles" is an example of  • true-breeding. • hybridization. • self-fertilizing. • inbreeding. • mixed breeding. 30

4. Which of these is NOT a reason that Mendel used pea plants as a model to study inheritance?  • There are many varieties with distinct and different characteristics. • They cannot self-fertilize. • It is easy to control cross-fertilizations. • The varieties he chose would show the same variant for a trait in generation after generation. • They have large flowers. :30

5. Which of the following are incorrectly matched for a single-factor cross?  • P generation / true breeding • F1 generation / monohybrid • F2 generation / result of F1cross • F1 generation / result of P cross • F2 generation / result of P cross :30

6. A cross of a true-breeding smooth pod and yellow pod plants results in all smooth pod offspring. This indicates that  • yellow is dominant and smooth is recessive. • smooth is dominant and yellow is recessive. • yellow and smooth are not alleles. • yellow and smooth are variants of the same gene. • two of the answers are correct. Yellow and smooth are variants of the same gene, and smooth is the dominant trait. :30

7. Participant Leaders

8. A male is heterozygous for the trait that produces freckles on the skin, and he has freckles. If he marries a woman who is also heterozygous for freckles, ______ percent of their children will be freckled and __________ percent of their children will be heterozygous.  • 100% freckled, 100% heterozygous • 75% freckled, 50% heterozygous • 75% freckled, 25% heterozygous • 50% freckled, 50% heterozygous • 100% freckled, 75% heterozygous :30

9. How can you determine the genotype of a plant showing the dominant phenotype of red color?  • The phenotype reflects the genotype, so the plant must be homozygous for the trait. •  Cross the red plant with a white plant to see if any white plants appear. • Cross the red plant with other red plants to see if any white plants appear. • Cross the red plant with a white plant to see how many red plants appear. • Cross the red plant with another red plant, and then cross the F1 population with each other to see if any white plants appear. :30

10. The single-factor crosses performed by Mendel support the observation that  • the two alleles for a given gene are distributed randomly among an individual's gametes. • the two alleles for a given gene are found within the same gamete. • if the recessive alleles for two different genes are on the same chromosome, they will never be found within the same gamete. • only the dominant alleles for a given trait are found in an organism's gametes. • if the dominant alleles for two different genes are on different chromosomes, they will never be found within the same gamete. :30

11. The two-factor crosses performed by Mendel support the observation that  • alleles for a given trait are distributed randomly among an individual's gametes independent of the alleles for other traits. • traits that are encoded by genes on different chromosomes are never found within the same gamete. • the F1 generation can display phenotypes in combinations different from those seen in the P generation. • the F2 generation will only display phenotypes in the same combinations as the P generation. • self-fertilization of the F1 generation will produce 100% heterozygous plants at both loci. :30

12. An organism that is heterozygous for two traits can produce a maximum of _______ different gametes for these traits.  • 2 • 4 • 2; if they are on the same chromosome • 4; only if they are on different chromosomes • 8 :30

13. Participant Leaders

14. Which of the following INCORRECTLY states a principle of the chromosome theory of inheritance?  • Genes are transmitted from parent to offspring via chromosomes. • Gametes contain either a maternal or paternal set of chromosomes. • Somatic cells contain a maternal and paternal set of chromosomes. • The paternal and maternal chromosomes assort randomly during meiosis. • Gametes are haploid and somatic cells are diploid. :30

15. A homologous pair of sister chromatids will possess _______ copies of the alleles for each locus.  • 2 • 4 • 8 • 1 • 50% of the :30

16. Which of the following accurately gives the distribution of phenotypes produced from a cross of purple dwarf pea plants that are heterozygous for flower color and plant height?  • 63 purple dwarf; 28 purple tall; 27 white dwarf; 7 white tall • 132 purple dwarf; 138 white tall • 54 purple dwarf; 6 white tall • 100% purple dwarf • 27 purple dwarf; 28 purple tall; 31 white dwarf; 29 white tall :30

17. What features of meiosis allow for independent assortment of chromosomes?  • random alignment of homologous sister chromatids on the metaphase plate • separation of sister chromatids • reduction of chromosome number from diploid to haploid • both the separation of sister chromatids and the reduction of chromosome number from diploid to haploid • All of these features allow for the independent assortment of chromosomes. :30

18. The probability of obtaining a dominant phenotype from self-fertilization of a heterozygous individual is  • 1/4 • 1/2 • 3/4 • 100% :30

19. 5 More Questions…

20. Cytogenetic is  • A photographic representation of chromosome. • The field of genetics that involves the microscopic examination of the chromosomes and cell division. • The sorting process to divide one cell nucleus into two nuclei. • The process by which the haploid cells are produced from a cell that was originally diploid. 10

21. DNA associates very tightly with nucleosomes because  • DNA can form covalent bonds with histone proteins. • negative charges on DNA are attracted to positive charges of the histone proteins. • the histone tails wrap tightly around the DNA double helix. • the amino acids of histone proteins are largely acidic, while DNA molecules are basic. 10

22. During metaphase,  • heterochromatin is converted to euchromatin. • chromosomes are about 30 nm wide. • chromosomes are much shorter than they were in interphase. • chromosomes undergo gene transcription. • the "beads on a string" structure is visible. 10

23. Which of the following statements is correct about the cell cycle?  • The cell cycle is a sequence of replication and division that produces a new cells. • The phase of the cell cycle are G1, S, and M phases. • In actively dividing cells, the S and G2 phases are collectively known as interphase. • When the S phase of the cell cycle is finished, a cell actually has twice as many chromatids as the number of chromosomes in the G1 phase. 1

24. Humans have __________ different types of autosomes.  • 46 • 44 • 23 • 22 • 11 1

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