Honors Biology EXAM 8
A brilliant zoologist examined an intestine cell from a crayfish and counted 200 single chromosmes. What was the chromosome count of the eggs in the crayfish was carrying?
100 single chromosomes
A world renowned cell biologist, carefully measured the quantity of DNA in grasshopper cells growing in cell culture. Cells examined during the G2 phase of the cell cycle contained 200 units of DNA. What would be the amount of DNA in one of the grasshopper daughter cells seen in telophase of mitosis?
100 units
In a human cell at prophase I, there are ___ tetrads
23
The kinetochore serves which of the following functions?
Kinetochores attach to microtubules during mitosis
Chromosomes are duplicated during ___ of the cell cycle?
S phase
If meiosis did not occur in sexually reproducing organisms, then:
chromosome number would double in each generation
The sources of genetic variation during meiosis are:
crossing-over and the random assortment of maternal and paternal chromosomes
A zygote contains the ____ complement of chromosomes.
diploid
A cell in G2
has twice the amount of DNA present in a telophase nucleus.
The correct number of chromosomes is maintained during sexual reproduction sexual reproduction by:
meiosis, which reduces the chromosome number by half
The M phase of the cell cycle involves two main processes, ____.
mitosis and cytokinesis.
The ___ is responsible for the separation of the chromosomes during ___ of mitosis.
mitotic spindle; anaphase
Which of the following represents the sequence of events during mitosis?
prophase- metaphase- anaphase- telophase
A cell is in metaphase if
the chromosomes are aligned on the equatorial plane of the cell
What is the function of nucleosomes?
to help DNA replicate
An animal with a diploid number of 36 chromosomes will have ___ chromosomes in its gammetes and ___ chromosomes in its somatic cells.
18;36
A human bone marrow cell, in prophase of mitosis contains 46 chromosomes. How many chromatids does it contain altogether?
92
___ contain identical DNA sequences and are held together by ____ during mitosis.
Sister chromatids; centromeres
To prevent disastrous consequences, the eukaryotic cell cycle is controlled by:
a series of cell cycle checkpoints
A maternal homologue and a paternal homologue synapse to form:
a tetrad
During which of the following stages of meiosis do the sister centromeres separate?
anaphase II
The functions of mitotic cell division in the life cycles of an organism may include:
asexual reproduction growth replacement of order cells repair of injured tissues
Cytokinesis in plant cell mitosis occurs by the formation of a(n):
cell plate
A culture of mouse cells is treated with a chemical that interferes with the activity of micro-filaments. Which of the following will probably be affected the most?
cytokinesis
Most human somatic cells are
diploid
Which of the following events does not occur in prophase II
formation of a new cell membrane
The image of the chromosomes of an individual organism is called a :
karyotype
The chromosomes are aligned at the spindle equator during
metaphase
A picture of a dividing pigeon cell taken through a microscope shows that the cell contains 7 chromosomes, each consisting of 2 chromatids. This picture could have been taken during
metaphase of mitosis S phase of the cell cycle G2 of the cell cycle prophase of mitosis
The mitotic spindle is made of
microtubules
The formation of female gamates is termed
oogenesis
Which of the following is not a location where meiosis occurs?
plant root tip
Which of the following are produced by meiosis?
polar bodies animal eggs animal sperm plant sperm
During which phase does crossing-over occur?
prophase I
Homologous chromosomes synapse or pair during
prophase I
Which of the following events does not occur during meiosis !
separation of sister chromatids
During prophase I of meiosis, homologous chromosomes lie side by side. This phenomenon is known as:
tetrad formation
Nucleosomes are best described as
Eukaryotic DNA associated with histone proteins
Mature nerve cells, which don't undergo cell division, are arrested in ____ of the cell cycle.
G1 phase
