Genetics And Plant Breeding - Study Mode

[#386] Who established that character is transmitted from generation to generation through chromosomes?
Correct Answer

(D) Strasburger and Hertwig

Explanation

Solution: Strasburger and Hertwig established that character is transmitted from generation to generation through chromosomes. Oscar Hertwig in 1876 studied fertilization in sea urchins while Strasburger (1877, 1884) made similar observations in plants. Hertwig noted the presence of two nuclei in the fertilized egg and concluded that fertilization involved the fusion of nuclei from two parental gametes. In 1888 he established that the nuclei of the germ cells of angiosperms undergo meiosis i.e., a reduction division yielding nuclei with half the number of chromosomes of the original nuclei.

[#387] The seven traits studied by Mendel were present in
Correct Answer

(C) 4 chromosomes

Explanation

Solution: The seven traits studied by Mendel were present in 4 chromosomes. Pea shape (round or wrinkled) Pea colour (green or yellow) Pod shape (constricted or inflated) Pod colour (green or yellow) Flower colour (purple or white) Plant size (tall or dwarf) Position of flowers (axial or terminal) All these seven contrasting characters of peas were located on 4 different chromosomes.

[#388] Sex in plants was discovered by
Correct Answer

(B) Camerarious

Explanation

Solution: Sex in plants was discovered by Camerarious. Rudolf Jakob Camerarius was a German botanist and physician. He is chiefly known for his investigations on the reproductive organs of plants. It was Camerarius who did experimental work and observed that plants seemed to have sex in some form, and guessed that pollen was the male fertilizing agent. In studying the mulberry, he determined that female plants not near to male (staminate) plants produced fruit but with no seeds.

[#389] Multiple factors hypothesis' is given by
Correct Answer

(B) Nilson Ehle

Explanation

Solution: Multiple factor hypothesis' is given by Nilson Ehle. A hypothesis to explain quantitative variation by assuming the interaction of a large number of genes (polygenes) each with a small additive effect on the character is a multiple factor hypothesis. Nilsson-Ehle was a Swedish geneticist working on various cereal crops in 1909. Many of the characters that he examined yielded 3 : 1 ratios in the F2 generation following the cross of two parental strains, consistent with expectations for a single segregating locus with one allele completely dominant over the other.

[#390] Ganga safed is a hybrid of
Correct Answer

(C) Maize

Explanation

Solution: Ganga safed is a hybrid of Maize. It is a Cross product of (CM 400 X CM 300X CM 600). Maturity varies from 95 to 100 days stem is medium thick with long narrow light green leaves. Grain is a medium round white and flintish. Yield potential is 50 - 55 q/ha. Plants are moderately resistant to Downey mildew, leaf blight rust borders, and also lodging. It is Suitable for maize-growing areas such as UP, Bihar, West Bengal and Rajasthan.