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% |
Nondisjunction of a pair of homologous chromosomes occurs during the anaphase of meiosis I. The four gametes produced as a result of this nondisjunction event will be:
1. | n + 1; n + 1; n - 1; n - 1 | 2. | n + 1; n - 1; n; n |
3. | n + 1; n - 1; n - 1; n - 1 | 4. | n + 1; n + 1; n; n |
Identify the chromosomal aberration:
1. | Inversion | 2. | Reciprocal translocation |
3. | Deletion | 4. | Duplication |
A couple comes to you for genetic counselling. Both have a sister affected with albinism but all other members are normal. Your advice regarding the risk of their child being affected with albinism would be:
1. | They must both be heterozygotes so their risk of having an affected child is ¼. |
2. | They might both be heterozygotes so they should get tested to see if they carry the disease allele or not. |
3. | Since neither one of them is affected, they are not at risk of having an affected child. |
4. | You can't give them any firm answers because you don't know their genotypes. |