Two garden pea dihybrids with round seed shapes and yellow seed color [RrYy] are intercrossed. Assuming independent assortment, the gene for seed shape is inherited by the progeny in a phenotypic ratio of:
1. | 3: 1 | 2. | 1: 1 |
3. | 9:3:3:1 | 4. | 1:1:1:1 |
Consider the following statements regarding
Y chromosome in humans:
I. | Y chromosome is a male-determining chromosome in humans |
II. | Y chromosome contains a gene, SRY, which triggers embryonic development as a male |
III. | 50 % of sons of a male inherit his Y chromosome |
Of the given statements, the correct statements are:
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
What decides the frequency of an allele in a population?
1. | Dominance |
2. | Its location on a particular chromosome |
3. | Its degree of expression |
4. | Natural selection |
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
1. | 4 | 2. | 8 |
3. | 16 | 4. | 32 |
The improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics because:
1. | it revealed new and unanticipated features of Mendel’s pea plant varieties. |
2. | it allowed biologists to study meiosis and mitosis, revealing the parallels between the behaviors of genes and chromosomes. |
3. | it allowed scientists to see the DNA present within chromosomes. |
4. | it led to the discovery of mitochondria. |
Male pattern baldness is a ___________ trait.
1. | Sex-linked | 2. | Sex-limited |
3. | Sex-influenced | 4. | Y-linked |
A sex aneuploid Drosophila has 2 sets of autosomes and sex chromosome complement XXY. This fly would be:
1. | A normal fertile female | 2. | A normal fertile male |
3. | An intersex | 4. | A metamale |
In humans, the condition red-green color blindness is a sex-linked recessive trait. In a family pedigree analysis, you find that two people with normal color vision have a color-blind son. This is possible if the genotypes of the parents are:
1. | XcXc and XcY | 2. | XcXc and XCY |
3. | XCXC and XcY | 4. | XCXc and XCY |
A woman has four daughters. The chance that her next child will be a son is:
1. | 1 | 2. | 0 |
3. | \(1 \over 2\) | 4. | \(1 \over 4\) |
In Drosophila melanogaster cinnabar eye is a sex-linked recessive trait. A female fly having cinnabar eyes is crossed with a wild-type male. The percentage of the male progeny of this cross with cinnabar eyes is expected to be:
1. | 0% | 2. | 25% |
3. | 50% | 4. | 100% |