BI 101, Prof. Baack, Practice questions for lecture exam #3.
Cell Cycle: Meiosis and Sexual Reproduction, Patterns of Inheritance, Genes and Proteins, Animal Development
NOTE: These questions are for practice purposes and are not all inclusive with respect to material covered.
1. Homologous chromosomes
a) always carry identical variants of genes d) are a set of chromosomes that the cell received from one parent
b) were formed when they separated during anaphase e) do not include the sex chromosomes
c) carry the same gene sequence
2. An organism has 26 chromosomes in its non-gamete cells. How many chromosomes will three of its eggs have?
a) 13 b) 39 c) 78 d) 26
3. An organism has 18 chromosomes in its gamete. How many chromosomes would there be in one non-gametic cell?
a) 18 b) 9 c) 36 d) 27 e) 54
4. How many chromatids does each chromosome have just prior to (before) replication?
a) none b) one c) two d) four e) three
5. In what process and stage do homologous chromosomes separate?
a) anaphase of mitosis b) prophase of mitosis c) anaphase II of meiosis d) prophase I of meiosis e) anaphase I of meiosis
6. Which of the following is the best description of the events of anaphase I?
a) Half of the chromosomes inherited from the mother and half of the chromosomes inherited from the father go to one pole of the cell.
b) All chromosomes inherited from the mother go to one pole of the cell; all chromosomes inherited from the father go to the other pole.
c) Homologous chromosomes separate and migrate to opposite poles; which homologue goes to which pole is random.
d) Sister chromatids separate; those inherited from the mother migrate to one pole, those inherited from the father go to the other pole.
7. Anaphase II is essentially the same as mitotic anaphase except that in anaphase II, ____________, and in mitotic anaphase _____________.
a) tetrads do not form; tetrads form
b) crossing over occurs; crossing over does not occur
c) the cells are haploid and sister chromatids separate; the cells are diploid and homologous pairs separate
d) chromosomes line up double file on the midline of the cell; chromosomes line up single file on the midline of the cell
e) the cells are haploid; the cells are diploid
8. Which of the following produces recombinant chromosomes?
a) fertilization b) non-disjunction c) crossing over d) replication
9. How much genetic material is present in a cell during prophase I as compared to a cell that has completed meiosis II?
a) four times as much b) ¼ as much c) twice as much d) the same amount e) ½ as much
10. How does prophase I differ from prophase II?
a) During prophase I there is one diploid cell; during prophase II there are two haploid cells.
b) During prophase I chromatin condenses, chromatin does not condense during prophase II.
c) During prophase I the nuclear envelope breaks up; during prophase II the nuclear membrane remains intact.
d) During prophase I chromosomes line up single file on at the equator; during prophase II the chromosomes line up in double file.
e) Crossing over does NOT occur during prophase I; crossing over DOES occur during prophase II.
11. What are alleles?
a) alternate phenotypes c) homologous chromosomes
b) environmental factors that affect gene expression d) alternate forms of a gene
12. A pure-breeding plant with yellow seeds is crossed with a pure-breeding plant with green seeds; all of the offspring have yellow seeds, why?
a) the yellow allele is recessive to the green allele c) all of the offspring are homozygous yellow
b) the alleles are codominant d) the yellow allele is dominant to the green allele
13. A pure-breeding plant with yellow seeds is crossed with a pure-breeding plant with green seeds to produce F1 plants with yellow seeds. What
is the expected phenotypic ratio of seed color of the offspring of a F1 x F1 cross?
a) 3:1 b) 9:3:3:1 c) 1:1 d) 1:2:1 e) 2:1
