Genetics And Plant Breeding - Study Mode
[#601] Which is female reproductive organ in a flower?
Correct Answer
(A) Carpels
Explanation
Solution: The carpel is a female reproductive organ in a flower. A carpel is the female reproductive part of the flower usually composed of the style and stigma and usually interpreted as modified leaves that bear structures called ovules, inside which egg cells ultimately form. Carpels are thought to be phylogenetically derived from ovule-bearing leaves or leaf homologues, which evolved to form a closed structure containing the ovules.
[#602] Which terminology is considered to be correct when two genotypes produce the same phenotype due to different environments?
Correct Answer
(C) Phenocopy
Explanation
Solution: When two genotypes produce the same phenotype due to different environments, it is known as Phenocopy. A phenocopy is a phenotypic trait or disease that resembles the trait expressed by a particular genotype, but in an individual who is not a carrier of that genotype. The phenocopy induced by the environmental conditions mimics the phenotype produced by a gene. For example, a phenocopy is observed in Himalayan rabbits which have a white-coloured coat along with a black tail, nose, and ears when raised in moderate temperatures.
[#603] Superiority of F 1 hybrid over a standard commercial variety is called
Correct Answer
(C) Economic heterosis
Explanation
Solution: The superiority of an F 1 hybrid over a standard commercial variety is called Economic heterosis. Heterosis is the improved or increased function of any biological quality in a hybrid offspring.
It refers to the superiority of F 1 over the standard commercial check variety. It is also called economic heterosis or useful heterosis and is calculated by using a formula.
[#604] Identify the test cross here.
Correct Answer
(B) Tt × tt
Explanation
Solution: Here, the test cross is Tt × tt. In a test cross, the individual in question is bred with another individual that is homozygous for the recessive trait, and the offspring of the test cross is examined. Here, ‘Tt’ is heterozygous dominant and the other parent ‘tt’ is homozygous recessive. By performing a test cross, one can determine whether the individual is heterozygous or homozygous dominant.
[#605] The movement of water from one cell of the cortex to the adjacent one in roots is due to
Correct Answer
(D) Water potential gradient
Explanation
Solution: The movement of water from one cell of the cortex to the adjacent one in the roots is due to the Water potential gradient. Water always moves from a higher energy state to a lower energy state. Water moves from soil to and through roots, through the xylem of plants, to the leaves, and eventually evaporates in the substomatal cavities of the leaf. The driving force for this flow is a water potential gradient.