Genetics And Plant Breeding - Study Mode
[#556] Incomplete dominace was first observed in which plant?
Correct Answer
(A) 4O' clock plant
Explanation
Solution: Incomplete dominance was first observed in the 4' O clock (Mirabilis jalapa) plant. This was first observed by Carl Correns. Incomplete dominance results from a cross in which each parental contribution is genetically unique and gives rise to progeny whose phenotype is intermediate. Incomplete dominance is also referred to as semi-dominance and partial dominance.
[#557] Heterosis most often exploited in
Correct Answer
(A) Cross pollinated species
Explanation
Solution: Heterosis is most often exploited in Cross pollinated species. cross-pollinated (hybrid) plants have “greater height, weight, and fertility” than their self-pollinated counterparts. The observation that cross-pollinated hybrids is more vigorous than their parents is nowadays commonly referred to as heterosis. Heterosis describes the phenomenon in which hybrids formed between individuals of the same or closely related species are more robust or vigorous than their parents. Thus, cross-pollinated species are often exploited.
[#558] Match the following columns: Column I (Expressions) Column II (Terminology) a. Alternative form of a gene which can not go together in the same gamete 1. Allele b. A phenotype caused by environment which resembles a phenotype causes by a gene. 2. Phenocopy c. Crossing of F 1 with homozygous recessive parent. 3. Test cross d. Gene which has masking effect on another gene 4. Epistic gene
Correct Answer
(A) a-1, b-2, c-3, d-4
Explanation
Solution: a. Alternative form of a gene that cannot go together in the same gamete is an allele. b. A phenotype caused by the environment which resembles a phenotype caused by a gene is Phenocopy. c. Crossing of F 1 with a homozygous recessive parent is a Test cross. d. Gene which has a masking effect on another gene is the Epistic gene.
[#559] Wheat crop is
Correct Answer
(B) Self-pollinated
Explanation
Solution: Wheat crop is a self-pollinated crops. The transfer of pollen from the anther of a flower to the stigma of the same flower or sometimes to that of a genetically identical flower is termed self-pollination. And plants that undergo this sort of pollination are termed self-pollinating crops. e.g: beans, broccoli, cabbage, carrots, cauliflower, corn and onions. wheat produces seed when pollen from anthers fertilizes the receptive ovary in the same flower of a single-parent plant.
[#560] The individuals with 2n ± 1 chromosomes are commonly known as
Correct Answer
(B) Aneuploid
Explanation
Solution: The individuals with 2n ± 1 chromosomes are commonly known as Aneuploid. Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example, a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any number of complete chromosome sets is called a euploid cell. An extra or missing chromosome is a common cause of some genetic disorders.