The recombination frequency between the genes a & c is 5%, b & c is 15%, b & d is 9%, a & b is 20%, c & d is 24% and a & d is 29%. What will be the sequence of these genes on a linear chromosome?
1.
a, c, b, d
2.
a, d, b, c
3.
d, b, a, c
4.
a, b, c, d
1. 100%
2. 25%
3. 50%
4. 75%
Select the correct statements with respect to pleiotropism:
| (a) | A gene is said to be pleiotropic if it affects more than one trait |
| (b) | Phenylketonuria is an example of pleiotropy |
| (c) | A condition where one gene has several alleles is referred to as pleiotropism |
| (d) | A trait is said to be pleiotropic if several genes control it |
Choose the correct answer from the options given below:
| 1. | (a) and (b) only | 2. | (a) and (d) only |
| 3. | (a), (b) and (c) only | 4. | (b), (c) and (d) only |
Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)
| Assertion (A): | A father will never pass the gene for haemophilia to his sons |
| Reason (R): | Haemophilia is sex-linked (X-linked recessive trait). |
In the light of the above statements, choose the correct answer from the options given below :
| 1. | (A) is True but (R) is False. |
| 2. | (A) is False but (R) is True. |
| 3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
Match List-I with List-II
| List-I | List-II | ||
| (a) | Haemophilia | (i) | Inborn error of metabolism which lacks an enzyme that converts phenylalanine into tyrosine |
| (b) | Down's Syndrome | (ii) | Sex-linked recessive disorder; a defect in blood coagulation |
| (c) | Phenylketonuria | (iii) | Presence of additional copy of X-chromosome (44+XXY) |
| (d) | Klinefelter's Syndrome | (iv) | Additional copy of chromosome number 21 |
Choose the correct answer from the options given below:
| (a) | (b) | (c) | (d) | |
| 1. | (ii) | (iv) | (i) | (iii) |
| 2. | (iv) | (ii) | (i) | (iii) |
| 3. | (ii) | (iii) | (i) | (iv) |
| 4 | (i) | (ii) | (iii) | (iv) |
Assuming that fur colour of an animal ranges from dark, intermediates shades, to white. A cross is made between a male (AABBCC) with dark fur colour and a female (aabbcc) with white fur colour. What would be the fur colour of F1 generation?
| 1. | All intermediate colour | 2. | Range of colour shade |
| 3. | All dark colour | 4. | All white colour |
In Drosophila, the genes for color of body and color of eyes are situated on _______.
1. both the sex chromosomes
2. autosomes
3. Y-chromosome
4. X-chromosome
A low frequency recombination indicates that the genes are:
1. Located far apart from each other
2. Located close to each other
3. Not linked
4. Present on different chromosomes
| I. | its four pairs of chromosomes |
| II. | a very large number of visible as well as biochemically mutant phenotypes |
| III. | easy and inexpensive maintenance |
| IV. | short generation time and large number of offspring |
2. I, II, and III only
3. II, III, and IV only
4. I, II, III, and IV
| 1. | The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them. |
| 2. | The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%. |
| 3. | All of the traits that Mendel studied–seed color, pod shape, flower color, and others–are due to genes linked on the same chromosome. |
| 4. | Linked genes are found on different chromosomes |
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