A dihybrid cross produces the following progeny - AaBb = 240; Aabb =754; aaBb = 746; aabb = 260. What is the distance between the two genes on the chromosome?
(1) 12.5 map units
(2) 1 map unit
(3) 20 map units
(4) 25 map units
Male pattern baldness is a trait
(1) sex-linked
(2) sex-limited
(3) sex-influenced
(4) Y-linked
A colour blind girl is rare because she will be born only when
(1) Her mother and maternal grand father were colour blind
(2) Her father and maternal grand father were colour blind
(3) Her mother is colour blind and father has normal vision
(4) Parents have normal vision but grand parents were colour blind.
Match each item in COLUMN I with one in COLUMN II and select your answer from the codes given:
COLUMN I | COLUMN II |
SCIENTIST | CONTRIBUTION |
Francis Crick | a. Breaking the genetic code |
Nirenberg | b. Established Caenorhabditis elegans as a model genetics study organism |
Benzer | c. Central dogma of molecular biology |
Brenner | d. Bacteriophase genetics |
A | B | C | D | |
1. | c | a | d | b |
2. | c | a | b | d |
3. | a | b | c | d |
4. | a | c | d | b |
Identify the incorrect statement regarding experiments on Pisum sativum by Gregor Mendel?
1. | He conducted hybridisation experiments on garden peas for seven years (1856-1863) and proposed the laws of inheritance in living organisms. |
2. | It was for the first time that statical analysis and mathematical logic were applied to problems in biology. |
3. | Unfortunately his experiments had a small sampling size, which gave less credibility to the data that he collected. |
4. | He investigated characters in the garden pea plant that were manifested as two opposing traits. |
Which of the following is a recessive trait for a character choosen by Mendel in garden pea?
1. Violet flower color
2. Yellow pod color
3. Axial flower position
4. Tall stem height
Genes which code for a pair of contrasting traits or slightly different forms of the same gene are known as
1. Alleles
2. Loci
3. Cistrons
4. Introns
Indentify the incorrect statement:
1. Tall plant produce gametes by meiosis and the dwarf plants by mitosis.
2. Only one allele is transmitted to a gamete.
3. The segregation of alleles is a random process.
4. Gametes will always be pure for the trait.
The law of Segregation is based on the fact that
(1) The Alleles do not show any blending
(2) There is random fertilization
(3) Gametes are pure for the trait
(4) The zygotes are diploid
The ultimate source of allelic variation is:
(1) Recombination
(2) Natural selection
(3) Mutation
(4) Drift