- Which of the following is not a function of mitosis in eukaryotes?
a. asexual reproduction
b. cell replacement and repair
c. genetic variation
d. growth
- During interphase
a. chromosomes begin to condense
b. DNA is replicated
c. nucleoli disappear
d. both b and c, but not a
e. all of the above
- In which part of interphase does the correct answer to the previous question occur?
a. G1
b. S
c. G2
- Which is the correct order of phases in mitosis and the cell cycle?
a. anaphase, prophase, prometaphase, metaphase, interphase, telophase
b. interphase, anaphase, prophase, prometaphase, metaphase, telophase
c. anaphase, telophase, interphase, prometaphase, metaphase, prophase
d. interphase, prophase, prometaphase, metaphase, anaphase, telophase
- The division of the cytoplasm to form two cells is known as:
a. cytokinesis
b. cytoplasmic fission
c. karyokinesis
d. physiognomy
- Which of the following is found in dividing plant cells but not in animal cells?
a. cell plate
b. centrioles
c. centrosomes
d. kinetochores
- Eukaryotes divide by mitosis and prokaryotes divide by:
a. binary fission
b. cleavage furrow formation
c. meiosis
d. mitosis
- Mitosis results in two daughter cells that:
a. each have double the number of chromosomes as the parent cell
b. each have double the number of chromatids as the parent cell
c. each have half the number of chromosomes as the parent cell
d. are genetically identical to the parent cell
- During G2 of interphase, a normal human somatic cell will have how many chromosomes?
a. 22
b. 23
c. 46
d. 92
- Identify the appropriate phase of mitosis and the cell cycle in which the following processes occur. (A = anaphase, B = prophase, C = telophase, D = interphase, E = metaphase).
- sister chromatids separate and chromosomes move apart
- mitotic spindle begins to form
- chromosomes replicate
- chromosomes line up at equatorial plane
- cell plate forms or cleavage furrow pinches cells apart
- nuclear membranes form around separated chromosomes
- chromosomes begin to condense
- nucleoli disappear
- Consider an organism in which the somatic cells are diploid, having 16 chromosomes per cell. Assume cytokinesis to occur in mid-telophase. How many chromosomes would be present in each cell during:
- anaphase?
- metaphase?
- at the close of telophase?
- the next G2 phase
- During cell plate formation, vesicles from what organelle coalesce at the metaphase plate?
a. chromosome
b. Golgi apparatus
c. phragmoplast
d. plasma membrane
- In sexual reproduction, two ? combine to form a ?.
a. diploid gametes; haploid zygote
b. haploid zygotes; diploid gamete
c. haploid gametes; haploid zygote
d. haploid gametes; diploid zygote
- At which phase of meiosis do each of the following occur?
- sister chromatids separate
- homologous chromosomes line up along the metaphase plate
- crossing over between homologous chromosomes
- chiasmata appear
- spindle fibers attach to kinetochores of chromosomes
- Which of the following mechanisms for introducing genetic variation is not particular to sexual reproduction?
a. crossing over
b. independent assortment
c. mutation
d. random fertilization
- Given an organism with a diploid number of 2N = 4. How many possible arrangements of chromosomes are there as a consequence of independent assortment alone?
a. 8
b. 16
c. 23
d. 8 million
- Which of the following events is not unique to meiosis?
a. crossing-over
b. homologous chromosomes pair
c. sister chromatids separate
d. synapsis
- Which of the following statements is correct?
a. Mitosis produces 4 identical daughter cells, whereas meiosis produces 4 genetically different daughter cells.
b. The products of mitosis are always diploid, whereas products of meiosis are haploid.
c. The chromosome number is reduced by half in meiosis, but not in mitosis.
d. Daughter cells produced by meiosis are genetically different from the parent but identical to each other.
- The restoration of the diploid chromosome number after halving in meiosis is due to:
a. chiasmata
b. fertilization
c. mitosis
d. gametogenesis
- The cells of the body which are diploid in the case of humans and do not undergo meiosis are:
a. gametes
b. germ cells
c. somatic cells
d. sporophytes
- Macaca mulatta (the Rhesus monkey) has a diploid number of 2N = 48. How many chromosomes will be present in cells undergoing meiosis after the end of meiosis I and before the beginning of meiosis II?
a. 12
b. 24
c. 48
d. 96
- As a result of meiosis, half of the gametes will receive one allele and the other half will receive the other allele. This is summarized as Mendel's law of:
a. heterozygosity
b. independent assortment
c. segregation
d. separation
- Which of the following disorders is dominantly inherited?
a. Huntington's disease
b. Phenylketonuria
c. Tay-Sachs disease
d. Sickle-cell anemia
- Cystic fibrosis is a recessively inherited disease. William has a sister who has cystic fibrosis. Neither of his parents have the disease. What are the chances that William also has cystic fibrosis?
a. 0 percent
b. 25 percent
c. 50 percent
d. 75 percent
- In a tetraploid organism, what is the maximum number of alleles that could be present for a given gene?
a. 1
b. 2
c. 4
d. 8
- Down Syndrome (trisomy 21) is an aneuploid situation where the affected individual:
a. has an extra sex chromosome
b. has an extra autosomal chromosome
c. is missing an autosomal chromsome
d. is triploid
- Aneuploidy and polyploidy arise as a result of:
a. chromosome breakage
b. independent assortment
c. meiotic non-disjunction
d. non-reciprocal translocation
- A chromosomal fragment becomes attached as an extra segment to a sister chromatid. This alteration is called a:
a. deletion
b. duplication
c. translocation
d. zygotic transformation
- A chromosomal fragment becomes attached to a chromatid of a non-homologous chromosome. This alteration is called a:
a. crossing-over
b. deletion
c. duplication
d. translocation
- In cattle, hornless (H) is dominant over horned (h). If two cattle that are heterozygous for the hornless trait are crossed, what percentage of the expected offspring would be hornless?
a. 25 percent
b. 50 percent
c. 75 percent
d. 100 percent
- Genetic material is exchanged between non-sister chromatids of homologous chromosomes. This is known as:
a. crossing-over
b. deletion
c. inversion
d. reciprocal translocation
- The situation where a gene at one locus alters the phenotypic expression of a gene at a different locus is called:
a. complete dominance
b. epistasis
c. pleiotrophy
d. pleisiomorphy
- When red snapdragons are crossed with white ones, the resulting offspring have pink flowers. This is an example of:
a. codominance
a. incomplete dominance
b. epistasis
d. polygenic inheritance
- The human ABO blood type system is an example of the situation where the phenotypes of both alleles are expressed in the heterozygote. This is called:
a. codominance
b. incomplete dominance
c. pleiotrophy
d. polygenic inheritance
- A man with type AB blood marries a woman with type O blood. What proportion of the offspring would be expected to have type A blood?
a. 0 percent
b. 25 percent
c. 50 percent
d. 100 percent
- Human skin color is controlled by at least three different genes. This is an example of:
a. codominance
b. epistasis
c. pleiotrophy
d. polygenic inheritance