mcdb homework week 5
A haploid set of unreplicated chromosomes (n = 4) of a fruit fly Drosophila melanogaster has a mass of 0.14 picogram (pg). What is the mass of DNA in a single fruit fly cell in prophase II?
0.28 pg
In a diploid set of chromosomes, one member of each pair of homologous chromosomes is derived from the father (paternal) and the other comes from the mother (maternal). If 2n = 6, what is the probability of obtaining a gamete in which all the chromosomes are paternal ones?
1/8
If each parent can produce 100 genetically distinct gametes, how many genetically distinct offspring can two parents produce?
10,000
Ignoring crossover, how many kinds of gametes can be produced by an organism with a diploid number of 8?
16
In humans, the haploid number of chromosomes is 23. Independent assortment has the possibility of producing __________ different types of gametes.
22^3
The genotype AABbCcDD of an individual characterizes how many genes?
4
The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic (body) cells of a rabbit?
44
In a diploid cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing __________ chromosomes.
5
In a certain plant, the alleles A, B, and C are completely dominant to the alleles a, b, and c. A plant with the genotype AABbcc will have the same phenotype as a plant with the genotype __________.
AaBBcc
Which function makes meiosis lengthier and more complex than mitosis?
All of the listed responses are correct.
Which, if any, of the following statements is true?
All of the listed responses are correct.
What is the difference between a benign tumor and a malignant tumor?
Cells of benign tumors do not metastasize; those of malignant tumors do.
Which of the following contributes to genetic variation in sexually reproducing species?
Independent assortment, crossing over, and random fertilization
The anticancer drug Taxol interferes with the separation of chromosomes during anaphase of mitosis. The likely mechanism of Taxol's action is
None of the choices are correct.
Which of the following occurs during anaphase II?
Sister chromatids separate and migrate toward opposite poles.
Which event occurs only during prophase I of the first meiotic division?
Synapsis and crossover of homologous pairs occur.
Pea plants are tall if they have the genotype TT or Tt, and they are short if they have genotype tt. A tall plant is mated with a short plant. Which outcome would indicate that the tall parent plant was heterozygous?
The ratio of tall offspring to short offspring is 1:1.
Tasmanian devil and a cucumber each have a diploid number of 14 chromosomes per somatic (body) cell. Why these two species are so dissimilar?
The two species have appreciably different genes.
3. If an organism that is homozygous dominant is crossed with a heterozygote for that trait, the offspring will be __________.
all of the dominant phenotype
Mendel's theory of particulate inheritance __________.
can explain inheritance patterns for virtually every sexually reproducing organism, but does not explain multifactorial (environmental) characters that affect organisms
What is the uncontrolled division of cells that results in malignant growth?
cancer
When observing some cultured fibroblasts, you notice that cell division stops once there is no free spaces between the cells. You are observing ________.
density-dependent inhibition.
In animals, fertilization is to zygote as meiosis is to which of the following?
gamete
A friend claims to have invented a way to cause wounds to heal more quickly. This might include manipulating
growth factors.
Through independent assortment alone, humans (2n = 46) can create 8,388,608 combinations of chromosomes. When also considering recombination during crossover, which expression is the best estimate of the number of chromosomal combinations?
infinitely more than 8,388,608
You would know a dividing cell was a plant cell rather than an animal cell if you saw that __________.
it had formed a cell plate
In sexually reproducing species, the chromosome number remains stable over time because __________ and __________ always alternate.
meiosis ... fertilization
In sexually reproducing species, the chromosome number remains stable over time because __________ and __________ always alternate.
meiosis; fertilization
At what stage is the independent assortment of chromosomes determined?
metaphase I alignment of paired homologs
To disrupt cytokinesis in a plant cell, you need to disrupt
microtubules near the cell plate.
Prophase I of meiosis is generally the longest phase of meiosis. Why might this be?
synapsis and crossover
If you used a chemical to block_______, cells would stall during the cell cycle and have twice the normal amount of DNA.
the G2 checkpoint
During binary fission in a bacterium __________.
the origins of replication move apart
Anchorage dependence displayed by animal cells is an example of external signals that regulate cell cycle.
true
At the end of telophase I of meiosis and the first cytokinesis, there are __________.
two haploid cells
