Biology test 3 practice questions
If a cell at metaphase of mitosis contains 20 sister chromatids, how many chromosomes will be present in a G1 cell?
10
In a diploid cell with 5 chromosome pairs (2n = 10 ) , how many centromere will be fun din a nucleus at G2 of the cell division cycle?
10
Cinnabar eye color is a sex-linked, recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type make, what percentage of the F1 males will have cinnabar eyes?
100%
When mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow-seeded. When he took these F1 yellow-seeded plants and crossed them to green-seeded plants, what genotypic ratio was expected?
1:1
If there are 40 centromeres in a cell at anaphase of mitosis, how Many chromosomes will be found in each daughter cell following cytokinesis?
20
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
2x
Quaking aspen trees can send out underground stems for asexual reproduction. Sexual reproduction is nota s common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems?
38
A man has 6 fingers on each hand and 6 toes on each foot. HIs wife and their daughter have the normal number of digits. Remember that extra digits is a dominant trait. What fraction of this couples children would be expected to have extra digits?
50% or 1/2
A triploid cell contains three sets of homologous chromosomes. If a cell of a diploid species that normally has 42 chromosomes per cell is a triploid, this cell would be expected to have which set of chromosomes?
63 chromosomes in 21 sets of 3
Starting with a fertilized egg (zygote) , a series of six cell divisions would produce an early embryo with how many cells?
64
Through a microscope, you can see a cell plate beginning to develop across the middle fo a cell and nuclei forming on either side of the cell plate. This cell is most likely ______
A plant cell in the process of cytokinesis
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in _____
Cells with more than one nucleus
What is the name of the microtubule-organizing center found in animal cells as an identifiable structure present during all phases of the cell cycle?
Centrosome
The drug cytochaslin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B?
Cleavage furrow formation and cytokinesis
Eukaryotic chromosomes are composed of which macromolecules?
DNA and proteins
The individual with the genotype AaBbCCDdEE can make many kids of gametes. Which correctly describes why this situation is possible?
Different possible assortment of chromosomes into gametes occurs
Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in
G1
Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged form 3 to 6 picograms per nucleus. In which stage of the cell cycle id the nucleus contain 6 picograms of DNA?
G2
Which statement is correct in comparing sexual and asexual reproduction?
In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.
Why are males more often affected by sex-linked traits than females?
Males are hemizygous for the X chromosome
Movement of the chromosomes during anaphase would be most affected by a drug that prevents which of the following events in mitosis and cell division?
Shortening of microtubules
Meiosis 2 is similar to mitosis in that
Sister chromatids separate during anaphase
What is the chromosomal makeup of each daughter cell after telophase of meiosis 1?
The cells are haploid, and the chromosomes are each composed of two chromatids.
The decline of MPF at the end of mitosis is caused by
The degradation of cyclin
Describe the law of independent assortment
The law of independent assortment describes the behavior of two or more genes relative to one another.
What characteristics do homologous chromosomes exhibit?
They carry information for the same traits
How did mendel account for the observation that traits had disappeared in the F1 generation and then reappeared in the F2 generation?
Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1
Red-Green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?
X^NX^n and X^NY
A human cell containing 22 autosomes and a Y chromosome is _____
a sperm
Metaphase is characterized by _____.
aligning of chromosomes on the equator of the cell
One difference between cancer cells and normal cells is that cancer cells ______
continue to divide even when they are tightly packed together
What event happens at the conclusion of meiosis 1 ?
homologous chromosomes of a pair are separated from each other
Scientists isolate cells in various phases of the cell cycle. They isolate a group of cells that have 1 1/2 times more DNA than G1 phase cells. What is the most likely part of the cell cycle from which these cells were isolated?
in the S phase of the cell cycle
The two homologs of a pair move toward opposite poles of diving cell during
meiosis 1
When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed fruit flies were male. What was the explanation for this result ?
the gene involved is located on the X chromosome
"If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be" Going off the cell lineage from above, the DNA content of a single cell at metaphase of meiosis 2 will be
x
