Chapter 13 Questions
Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms (pg) per nucleus. During the entirety of which stage of the cell cycle did the nucleus contain 6 pg of DNA?
G2
Which of the following statements correctly describes how sister chromatids and homologous chromosomes differ from each other?
Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.
Which of the following statements about reproduction is correct?
In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.
Which of the following phases make up the stages of mitosis?
Prophase, prometaphase, metaphase, anaphase, and telophase
Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Which of the following statements best represents the connection between reproduction and evolution?
Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.
Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?
The cells are haploid, and the chromosomes are each composed of two chromatids.
What must happen to a chromosome before a cell starts mitosis?
The single DNA molecule in the chromosome must be replicated. - Before a cell starts mitosis, its chromosomes must be duplicated. This includes replicating the single DNA molecule of a chromosome, resulting in two sister chromatids of a duplicated chromosome that are attached along their lengths. The chromosomes condense during prophase of mitosis
Which of the following characteristics are part of the sexual life cycle of most fungi but are not part of the sexual life cycles of plants or animals?
a unicellular haploid stage
Which of the following events characterizes metaphase of mitosis?
alignment of the chromosomes at the equator
During which of the following phases of meiosis do homologous chromosomes separate?
anaphase I
During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell?
anaphase II
During which of the following processes do sister chromatids separate from each other?
during both mitosis and meiosis II
Many diploid organisms produce haploid gametes for reproduction. Which of the following best describes how the diploid number of chromosomes is restored in the offspring of these organisms?
fertilization combines chromosomes from each parent into resulting zygote
Genetic variation occurs when chromosomes are shuffled in fertilization and what other process?
meiosis - Variation is produced as a result of independent assortment and crossing over in meiosis.
Asexual reproduction occurs during which of the following processes?
mitosis
Asexual reproduction __________.
produces offspring genetically identical to the parent
In alternation of generations, what is the diploid stage of a plant that follows fertilization called?
sporophyte
Which of the following processes occurs in meiosis but not in mitosis?
synapsis of chromosomes
In a typical animal, mitosis produces _________, while meiosis produces____________
two diploid daughter cells, four haploid daughter cells
What number and types of chromosomes are found in a human somatic cell?
44 autosomes and 2 sex chromosomes - Human somatic cells contain 22 pairs of autosomes and either two X chromosomes (in females) or an X and a Y chromosome (in males).
Which of the following statements describes an example of alternation of generations?
A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte).
