Genetics And Plant Breeding - Study Mode
[#781] When development of fruit occurs without fertilization, is known as
Correct Answer
(B) Parthenocarpy
Explanation
Solution: When the development of fruit occurs without fertilization, is known as Parthenocarpy . In some plants, however, the fruit develops without fertilization, a phenomenon is known as parthenocarpy. Parthenocarpic fruit has advantages over seeded fruit, longer shelf life and greater consumer appeal. SEEDLESS FRUIT such as navel oranges is propagated asexually, usually by grafting.
Parthenogenesis occurs when there is less availability of functional eggs or sperms or when pollination fails to occur.
[#782] The stalk of the ovules is called
Correct Answer
(C) Funicle
Explanation
Solution: The stalk of the ovules is called Funicle. The ovule is the structure that gives rise to and contains the female reproductive cells. The ovule is a small structure present in the ovary. It is attached to the placenta by a stalk called a funicle. The funicle provides nourishment to the ovule.
[#783] Potassium ion exchange hypothesis of opening and closing of stomata was closed by
Correct Answer
(B) Levitt
Explanation
Solution: The potassium ion exchange hypothesis of the opening and closing of stomata was given by Levitt. According to this theory, the opening and closing of stomata depend on the production of potassium ion gradient. When the concentration of potassium ions increases in the guard cell, it allows the guard cell to absorb water from the surrounding cells. This turgidity of the guard cell cause opening of the stomata. However, a decrease in the concentration of potassium ions, makes guard cell flaccid and ultimately closed.
[#784] When both additive and non-additive genetettcets are important in the expression of a trait, the most appropriate solution scheme is
Correct Answer
(A) Pure line
Explanation
Solution: When both additive and non-additive genetettcets are important in the expression of a trait, the most appropriate solution scheme is the Pure line. Additive genetic influence (A) describes the effect of multiple genes that exert influence in a linear or additive fashion. Non-additive genetic factors (NA), by contrast, describe the interactive effects of different alleles and include genetic dominance and epistasis. A pure line means those breeds of organisms that have been generated through repeated self-fertilization and have become homozygous for a particular trait.
[#785] After chromosome doubling the allopolyploid have 2 homologous chromosomes for each chromosome present in the F1 hybrid, which is the same situation as in the diploid species is known as
Correct Answer
(B) Amhidiploid
Explanation
Solution: After chromosome doubling the allopolyploid have 2 homologous chromosomes for each chromosome present in the F1 hybrid, which is the same situation as in the diploid species known as Amhidiploid. It is a plant originating from hybridization between two species in which the chromosome number is the sum of the chromosome numbers of both parental species. It behaves as an independent species. Amphidiploid is a plant having the sum of the chromosome numbers of two parental species, owing to the doubling of the chromosomes in a hybrid of two species.