The behaviour of chromosomes and genes can be compared with each other is best explained by which of the following statement?
(1) occur in nucleus
(2) both segregate at the time of gamete formation leading to transmittance of complete pair to a gamete.
(3) Independent pairs( gene) or pair of chromosomes segregate independently of each other or of other pair.
(4) The two alleles of a gene pair are located on homologous site on homologous chromosomes.
The chromosome movement during meiosis have been worked out
(1) 1900
(2) 1902
(3) 1911
(4) 1930
Consider the following statement and find out the incorrect one:
(1) Advancement in Microscopy made the study of chromosomal behaviour possible.
(2) The two alleles of a gene pair are located on homologous site on homologous chromosomes.
(3) Experimental verification of chromosomal theory of Inheritance was done by T. H. Morgan et. Al.
(4) Morgan Chose Drosophila as an experimental animal because it has variations that can be seen with high power of microscope.
Linkage was described by Morgan in Drosophila. Which of the following combinations are correct?
(i) He hybridised yellow bodied, white-eyed females to brown-bodied, red eyed males and then intercrossed their F1
(ii) The ratio of F2 generation is same as that of 9:3:3:1 in this cross.
(iii) The parental combinations are observed more than recombinants.
(iv) According to Morgan Linkage was observed due to chemical association of genes.
(v) All the genes present on same chromosomes have same efficiency to link.
(1) (ii), (iv), (v)
(2) (i), (iii)
(3) (i), (iii), (v)
(4) (i) and (iv)
Mendel’s success was largely due to his choice of the garden pea plant for his experiments. The advantages of using this plant included:
I. Presence of easily observable contrasting traits for many characters.
II. It was possible to control pollination [and hence mating] between different pea plants.
III. A large number of seeds could be produced and statistical analysis was therefore more accurate.
IV. A long generation time means expression of all traits completely.
V. Many observable traits were controlled by single genes.
1. Only I, II and III
2. Only I, II and V
3. Only I, II, III and V
4. Only II, III, IV and V
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
(1) There is considerable genetic variation in garden peas.
(2) Traits are inherited in discrete units, and are not the results of ʺblending.ʺ
(3) Genes are composed of DNA.
(4) An organism that is homozygous for many recessive traits is at a disadvantage.
An organism with two copies of the same allele is:
(1) Homozygous for that trait
(2) Homologous for the allele
(3) Heterozygous for that trait
(4) Heterologous for the allele
Which of the following about the law of segregation is true?
(1) It states that each of two alleles for a given trait segregate into same gametes.
(2) It can be explained by the segregation of heterologous chromosomes during meiosis.
(3) It can account for the 3:1 ratio seen in the F2 generation of Mendelʹs crosses.
(4) It is a method that can be used to determine the number of chromosomes in a plant.
In guinea pigs, black coat color is a dominant trait and white is a recessive trait. When heterozygous black pigs are intercrossed the chance of the first two offspring being black is:
(1) 75 %
(2) 56 %
(3) 44 %
(4) 6 %
The minimum progeny population size allowing for random union of all kinds of gametes from AaBbCc parents is:
(1) 9
(2) 16
(3) 27
(4) 64