Biology- EXAM 3
Compare the processes of spermatogenesis and oogenesis in humans. Which process takes longer?
oogenesis takes much longer (days or more) than spermatogenesis
What is the result when a diploid cell undergoes mitosis?
2 diploid cells
How many sites are there on the ribosome where tRNAs can bind?
3
How many chromosomes are in a human skin cell that is in the G1 portion of the cell cycle?
46
How many pairs of sister chromatids would you expect to see in a human skin cell that was exiting G2 of the cell cycle?
46
What is the order of information flow during gene expression?
DNA--->RNA--->Protein
What organism did Thomas Hunt Morgan use in his genetic studies?
Drosophila melanogaster (fruit fly)
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism?
HT
A father has blood type A. The mother has blood type B. They have a child with blood type O. What is the genotype of the father?
IAi
Which enzyme is responsible for making the RNA during transcription?
RNA polymerase
A person has found out that both his father and his mother are both carriers of the cystic fibrosis trait. This person does not have cystic fibrosis. What is the chance that he is a carrier of the trait?
a 2/3 chance
If one parent is heterozygous for Huntington's disease and the other is homozygous (normal), what is the chance that a child of theirs will have Huntington's disease?
a 50% chance
One parent is heterozygous for Dwarfism and the other is homozygous (normal), what is the chance that a child of theirs will have Dwarfism?
a 50% chance
A human cell contains 22 autosomes and a Y chromosome. What is this cell?
a sperm cell
Wolves are sometimes observed to have black coats and blue eyes. Assume that these two traits are unlinked. Assume further that normal coat color (G) is dominant to a black coat (g), and brown eyes (B) are dominant to blue (b). If a black male with blue eyes and a female that is heterozygous for both traits produce offspring. What fraction of the offspring would be heterozygous for both traits?
about 1/4
Wolves are sometimes observed to have black coats and blue eyes. Assume that these two traits are unlinked. Assume further that normal coat color (G) is dominant to a black coat (g), and brown eyes (B) are dominant to blue (b). If a black male with blue eyes and a female that is heterozygous for both traits produce offspring. What percent of the offspring will be normal colored with blue eyes?
about 1/4
A female fruit fly heterozygous for eye color is crossed with a red-eyed male. What will be the eye color of their progeny?
all of the females will have red eyes while half of the males will have red eyes and half will have white eyes
Different forms of a gene are called
alleles
A typical mRNA found in the cytoplasm of a eukaryotic cell will have all of the following features EXCEPT:
an intron
The portion of mitosis where the sister chromatids have separated and are starting to be pulled to the opposite sides of the cell is called
anaphase, telophase
A baby is born with only one X chromosome (X). What type of genetic problem is this?
chromosomal aberration
Which of the following processes occurs when homologous chromosomes cross over in meiosis 1?
corresponding segments of non-sister chromatids are exchanged
Which of the following terms belongs with the word synapsis, tetrads, and chiasmata?
crossing over
Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. The relationship between genes S and N is an example of _____.
epistasis
Cloud leopards are an endangered species of cat, living in the very wet cloud forests of Central America. Assume that normal spots (Xn) are a dominant, X chromosome-linked trait and that dark spots are the recessive counterpart. If a heterozygous normal spotted female is crossed with a dark spotted male what is the phenotype of the progeny?
half of the males will have normal spots and half will have dark spots, half of the females will have normal spots and half will have dark spots
You have two copies of chromosome ten, one from your mother and one from your father. These chromosome are
homologous chromosomes
If a person is has two identical alleles, he/she is for that gene.
homozygous
Which of the following cells are haploid?
human sperm cells
What type of division is the cell in the picture undergoing? For this organism 2n=4.
mitosis
A woman is a carrier of the color blind trait and her husband has normal color vision. What percentage of the children will be colorblind?
none of the girls will be colorblind but one half of the boys will be colorblind
The gene for black or grey body color in fruit flies (b) has a recombination rate of 17% with the gene for vestigial wings (vg). The gene for black or grey body color in fruit flies has a recombination rate of 9% with the gene for red or cinnabar eyes (cn). Which statement below is true?
the gene b is closer to the gene cn than the gene vg
A couple has a son who has hemophilia. Neither parent has hemophilia and none of the grandparents have hemophilia. Which grandparent MUST be a carrier of the hemophilia allele?
the maternal grandmother
A couple has a son who has hemophilia. Neither parent has hemophilia. Which parent or parents have the hemophilia trait?
the mother has the trait, the father does not
Where does transcription and translation take place in a eukaryotic cell?
transcription takes place in the nucleus while in translation it takes place in the cytoplasm