GUIDE QUESTIONS AND ANSWERS
1. During meiosis, homologous chromosomes separate at
___.
Answer
2. If a cell begins meiosis with a 2n (diploid) number of 16, how
many chro- mosomes are there in the cell at prophase I?
Answer Prophase I is the initial stage of meiosis, when duplicated chromosomes first
become visible but no division of chromosomes or cell division has yet occurred; so, 16 chromosomes
(the diploid number) are present. if the diploid number of chromosomes is 16, then each haploid
daughter cell would contain 8 chromosomes.
3. If a cell begins meiosis with a 2n (diploid) number of 16, how many
chromo-
somes are there in each cell at metaphase II?
Answer 8
4. If a cell has 30 chromosomes before mitosis, how many does each
daughter cell have afterward?
Answer The purpose of mitosis is to turn a single parent cell into two genetically identical
daughter cells. Therefore, if the parent cell has 30 chromosomes, then each daughter cell will also have 30
chromosomes after mitosis
,5. In humans, meiosis
produces cells that are .
Answer Meiosis is referred to as reduction division because it results in cells that are haploid; the
resulting cells are specialized sex cells called gametes.
6. Which of the following is the last stage of mitosis?
Answer TELOPHASE
7. Which of the following terms describes a failure of
chromosomes to sort properly during meiosis?
Answer Nondisjunction
8. Diploid cells become haploid
during .
Answer Meiosis I
9. In meiosis II, .
Answer sister chromatids are separated into different daughter cells
10. Crossing over between homologous chromosomes normally
occurs
.
Answer Crossing over between homologous chromosomes normally occurs during prophase I.
,11. a laboratory technique that produces an image of an
individual's chromo- somes
Answer a karyotype
12. Plant cells divide by .
Answer mitosis followed by cytokinesis by cell plate formation
Plant cells nuclear division occurs through mitosis. Their cytoplasm is divided through cytokinesis by cell-
plate formation.
13. Why are no two gametes exactly alike genetically?
Answer Each gamete has a different combi- nation of parental chromosomes that is the
result of both crossing over and independent assortment.
14. A human skin cell, in prophase of mitosis, contains 46
chromosomes. How many chromatids does it contain in total?
Answer A sister chromatid is one of the two identical DNA molecules that make up a
duplicated chromosome. A cell in prophase of mitosis has already undergone chromosomal duplication
(DNA replication). Each chromosome will consist of a pair of sister chromatids. Therefore, if the cell has
46 chromosomes, there will be a total of 92 chromatids.
15. Which of the following is true about prophase I?
Answer It involves pairing up of homologous
chromosomes.
, 16. If a cell begins meiosis with a 2n (diploid) number of 16, how
many chro- mosomes are there in the cell at anaphase I?
Answer The correct answer is 16 because, although the homologous chromosomes are
separated during anaphase I, telophase I and cytokinesis have not yet occurred to produce the two
haploid daughter cells that are the final product of meiosis I.
17. Which of the following is true about meiosis II?
Answer Meiosis II is the second division of meiosis, and it results in the production of
four haploid cells.
18. are the number of chromosomes found in a somatic eukaryotic
cell constant during its entire life ?
Answer The number of chromosomes found in a somatic eukaryotic cell is constant during its
entire life.
Although the number of chromosomes varies by species, each individual somatic (body) cell within a species
will always have the specific number of chromosomes characteristic of that species (constant over its entire
life). For example, a human cheek cell, liver cell, or bone cell will all always have 46 chromosomes (except
for the brief period between mitotic anaphase and cytokinesis when the number of chromosomes
doubles).
19. A human somatic (body) cell
has chromosomes.
Answer Different organisms have