A normal-visioned man whose father was colour-blind, marries a woman whose father was also colour-
blind. They have their first child as a daughter. What are the chance that this child would be colour–blind?
1. | 100% | 2. | zero percent |
3. | 25% | 4. | 50% |
If two persons with 'AB' blood group marry and have a sufficiently large number of children, these children could be classified as 'A' blood group: 'AB' blood group: 'B'blood group in a 1:2:1 ratio. The modern technique of protein electrophoresis reveals the presence of both' A' and 'B' type proteins in 'AB' blood group individuals. This is an example of:
1. | Incomplete dominance | 2. | Partial dominance |
3. | Complete dominance | 4. | Codominance |
What is applicable to both Klinefelter’s syndrome and Turner’s syndrome?
I. | They result from the non-disjunction of sex chromosomes during gamete formation |
II. | They can be identified by a karyotype |
III. | They have 44 autosomes |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
If a father and son are both affected by red-green colour blindness, then what can be said definitely?
I. | The son has received the trait from the father. |
II. | The mother of the affected son has to be affected by red-green colour blindness. |
III. | Any sister of the affected son can never be affected by red-green colour blindness. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | None |
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 |