Ch. 10
In a human cell at prophase I, there are ____ tetrads.
23
The cell cycle of a typical somatic cell consists of the ____ and M phases.
Interphase
What is the function of kinetochores?
Kinetochores attach to microtubules during mitosis.
___ contain identical DNA sequences and are held together by ____ during mitosis.
Sister chromatids; cohesin proteins
A bacterial chromosome consists of a
circular DNA molecule many times larger than the cell
A cell in the G2 phase:
has twice the amount of DNA present in a telophase nucleus
The mitotic spindle is made of
microtubules
The M phase of the cell cycle involves two main processes:
mitosis and cytokinesis
The ____ is responsible for the separation of the chromosomes during the ____ of mitosis.
mitotic spindle; anaphase
During prophase I of meiosis, homologous chromosomes lie side by side. This phenomenon is known as
tetrad formation
A cell is dividing by binary fission. What can you conclude?
the cell is prokaryotic
What would happen if meiosis did not occur in sexually reproducing organisms?
the chromosome number would double in each generation
When is a cell in metaphase?
the chromosomes are aligned at the midplane of the cell
Chromosomes are duplicated during the ____ of the cell cycle.
S phase
To prevent disastrous consequences, the eukaryotic cell cycle is controlled by
a series of cell cycle checkpoints
During which stage of meiosis do the sister chromatids separate?
anaphase II
Plant hormones known as ____ stimulate mitosis.
cytokinins
Nucleosomes are best described as:
eukaryotic DNA associated with histone proteins
During prophase I, each chiasma represents
site of crossing over
An animal with a diploid number of 36 chromosomes will have ____ chromosomes in its gametes and ____ chromosomes in its somatic cells.
18-36
Which of the following is produced by meiosis?
Animal gametes
____organized on chromosomes carry the information that controls the functions of the cell.
Genes
Homologous chromosomes undergo synapsis during
Prophase I
What is not a hallmark of prophase?
Spindle fibers pull chromosomes to opposite sides of the cell.
Duplicated centrioles move to opposite poles of a dividing ____ cell during the ____ of the cell cycle.
animal; prophase
Cytokinesis in plant cells occurs via the formation of a(n)
cell plate
During prophase, ____ is(are) compacted into visible chromosomes.
chromatin
What evolutionary advantage is provided by sexual reproduction?
increased genetic diversity
At the completion of oogenesis, ____ are produced.
one egg cell and three polar bodies
The function of nucleosomes is to
prevent DNA strands from tangling.
Homologous chromosomes can be identified and/or characterized by
their similar and characteristic staining patterns