Chapter 2 Flashcards
Assume that a cell has six chromosomes while it is in the G1 stage of the cycle.
How many chromosomes and how many DNA molecules will it have in the G2 stage?
3 chromosomes and 6 DNA molecules 12 chromosomes and 24 DNA molecules 6 chromosomes and 6 DNA molecules 6 chromosomes and 12 DNA molecules 12 chromosomes and 12 DNA molecules
6 chromosomes and 12 DNA molecules
in which stage of meiosis does the separation of homologous chromosomes occur?
prophase I telophase II metaphase II anaphase I anaphase II
anaphase I
meiosis results in genetic variation among its product cells
one source of this genetic variation is the random distribution of maternal and paternal chromosomes, and the other source of genetic variation is ?
the division of the cytoplasm at cytokinesis
crossing over occurring at prophase I
the arrival of chromosomes at the spindle pols in telophase I
chromosomes condensing at prophase II
the reforming of the nuclear envelope at interkinesis
crossing over occurring at prophase I
which of the statements is not a difference between mitosis and meiosis ?
in mitosis there is one cell division which in meiosis there are two cell divisions
mitosis usually produces two daughter cells while meiosis usually produces four cells
sister chromatids separate during mitosis but not during meiosis
the product of mitosis are usually genetically identical but the products of meiosis are genetically different
homologous chromosomes pair in meiosis but not in mitosis
sister chromatids separate during mitosis but not during meiosis
how many ova, plural for ovum, can be produced from two primary oocytes through meiosis ?
16 8 4 2 1
2
What are the functions of mitotic cell division?
asexual reproduction
replacement of cells
production of gametes
growth of multicellular organisms
asexual reproduction
replacement of cells
growth of multicellular organisms
G1/S checkpoint
maintains cell until necessary enzymes for replication are synthesized
G2/M checkpoint
detection of DNA damage after replication
spindle-assembly checkpoint
ensures that each chromosome is attached to spindle fibers from opposite poles
What are checkpoints?
transition points during the cell cycle that ensure all cellular components are functioning properly
control points on protein synthesis that limit cancerous growth
periods of growth and development between cell divisions
transition points during the process of chromosome separation that allow cell division to begin
transition points during the process of DNA replication that allow cell division to begin
transition points during the cell cycle that ensure all cellular components are functioning properly
Cell division by mitosis is a mechanism of asexual cell replication. Some single‑celled organisms reproduce by cell division, and cell division enables multicellular organisms to grow and to repair damaged cells.
Which is a product of cell division by mitosis?
daughter cells that are genetically variable
daughter cells with half the number of chromosomes
two daughter cells with identical chromosomes
four genetically similar daughter cells
two daughter cells with identical chromosomes
What happens during anaphase II of meiosis?
Homologous chromosomes separate, but sister chromatids remain joined at their centromeres.
Sister chromatids separate from each other and migrate to opposite ends of the cell.
Homologous chromosomes are randomly arranged in the middle of the cell.
Sister chromatids are distributed in a single layer across the center of the cell.
Homologous chromosomes form, and crossing over occurs between them.
The nuclear membrane begins to form around haploid sets of chromosomes.
Sister chromatids separate from each other and migrate to opposite ends of the cell.
What happens during anaphase I of meiosis?
Sister chromatids separate from each other and migrate to opposite ends of the cell.
Homologous chromosomes separate, but sister chromatids remain joined at their centromeres.
The nuclear membrane begins to form around haploid sets of chromosomes.
Homologous chromosomes are randomly arranged in the middle of the cell.
Homologous chromosomes form, and crossing over occurs between them.
Sister chromatids are distributed in a single layer across the center of the cell.
Homologous chromosomes separate, but sister chromatids remain joined at their centromeres.
What happens during telophase II of meiosis?
Homologous chromosomes form, and crossing over occurs between them.
The nuclear membrane begins to form around haploid sets of chromosomes.
Homologous chromosomes separate, but sister chromatids remain joined at their centromeres.
Homologous chromosomes are randomly arranged in the middle of the cell.
Sister chromatids separate from each other and migrate to opposite ends of the cell.
Sister chromatids are distributed in a single layer across the center of the cell.
The nuclear membrane begins to form around haploid sets of chromosomes.
Meiosis and mitosis are both forms of cell division. However, the outcomes of these processes differ. Consider a diploid organism with two sexes.
Select the reasons why meiosis typically produces genetic variation, whereas mitosis does not.
Mitosis produces two identical diploid daughter cells.
Gametic chromosomes have a different combination of alleles than parental chromosomes as a result of independent assortment.
1n gametes produced in mitosis fuse to produce 2n cells in meiosis.
Sister chromatids are not genetically identical as a result of crossing over during meiosis.
Mitosis produces two identical diploid daughter cells.
Gametic chromosomes have a different combination of alleles than parental chromosomes as a result of independent assortment.
Sister chromatids are not genetically identical as a result of crossing over during meiosis.
