52 terms

Bio Questions Ch 8

Which of the following statements regarding the function of mitosis is false?
Mitosis allows organisms to generate genetic diversity.
Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are
homologous chromosomes.
A pair of sex chromosomes found in a human male is most like
a bride and groom
Which of the following statements regarding mitosis and meiosis is false?
Mitosis produces daughter cells with half the number of chromosomes as the parent cell.
Which of the following statements is false?
An X chromosome is an autosome
During which stage of meiosis do synapsis and crossing over occur?
prophase I
Which of the following options correctly describes the behavior of a tetrad during anaphase I of meiosis?
It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell.
Which of the following statements regarding the differences between mitosis and meiosis is false?
Crossing over is a phenomenon that creates genetic diversity during mitosis.
Which of the following statements regarding mitosis and meiosis is false?
Meiosis provides for asexual reproduction.
Both mitosis and meiosis are preceded by
Independent orientation of chromosomes at metaphase I and random fertilization are most like
shuffling cards and dealing out hands of poker.
Independent orientation of chromosomes at metaphase I results in an increase in the number of
possible combinations of characteristics
Which of the following statements regarding genetic diversity is false
Genetic diversity is enhanced by mitosis
At a chiasma, two ________ are attached to each other
homologous or non-sister chromatids
Without crossing over
genetic recombination could not occur.
can reveal alterations in chromosome number.
A karyotype is most like
photographs of every couple at a high school prom.
Which of the following statements regarding Down syndrome is false
Down syndrome is least likely to be seen in the infants of mothers over 40.
Nondisjunction occurs when
members of a chromosome pair fail to separate.
Which of the following statements about nondisjunction is false?
In mammals, extra copies of the Y chromosome are typically inactivated.
Which of the following types of organisms commonly demonstrates polyploidy?
flowering plants
How many generations does it take to develop a new plant species by polyploidy?
Which of the following variations of the sentence "Where is the cat" is most like a chromosomal deletion?
Where is cat?
If a chromosome fragment breaks off and then reattaches to the original chromosome, but in the reverse direction, the resulting chromosomal abnormality is called a(n)
The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called
asexual reproduction.
Which of the following statements regarding sexual and asexual reproduction is true
Sexual reproduction is more likely to increase genetic variation than is asexual reproduction
Asexual reproduction requires ________ individual(s).
Which of the following statements regarding cell division is false?
Cell division is common in eukaryotes but rare in prokaryotes.
Which of the following statements regarding prokaryotes is false?
Prokaryotic chromosomes are more complex than those of eukaryotes.
Eukaryotic chromosomes differ from prokaryotic chromosomes in that they
are housed in a membrane-enclosed nucleus.
Which of the following helps maintain the structure of chromosomes and control the activity of genes?
Sister chromatids are
joined together at a centromere.
Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called
sister chromatids
Eukaryotic cells spend most of their cell cycle in which phase
Which of the following occurs during interphase?
cell growth and duplication of the chromosomes
The genetic material is duplicated during
the S phase
The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called
Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! Then you realize that this cell is
undergoing cytokinesis
The phase of mitosis during which the mitotic spindle begins to form is
During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles?
At the start of mitotic anaphase,
the centromeres of each chromosome come apart.
During which phase of mitosis does the nuclear envelope re-form?
Which of the following is a feature of plant cell division that distinguishes it from animal cell division?
formation of a cell plate
Which of the following features likely accounts for the difference between plant and animal cell cytokinesis?
Plant cells have cell walls.
Which of the following must occur for a plant or animal to grow and develop normally?
The organism must be able to control the timing and rate of cell division in different parts of its body.
When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of
density-dependent inhibition
Which of the following is probably the main factor responsible for the phenomenon of density-dependent inhibition?
physical contact of cell-surface proteins between adjacent cells
Mature human nerve cells and muscle cells
are permanently in a state of nondivision.
Which of the following statements regarding the cell-cycle control system is false?
The cell-cycle control system operates independently of the growth factors.
You are asked to culture an unidentified sample of animal tissue. You notice that the cells seem to fail to exhibit density-dependent inhibition. The source of this tissue sample is most likely
a cancer.
A benign tumor differs from a malignant tumor in that a benign tumor
does not metastasize
Which of the following shows the greatest promise as a cancer chemotherapy agent?
a drug that prevents mitotic spindle from forming