Genetics And Plant Breeding - Study Mode

[#956] Genes for Male sterility in plants are mainly located in
Correct Answer

(A) Mitochondrial genome

Explanation

Solution: Genes for Male sterility in plants are mainly located in the Mitochondrial genome. In plants, male sterility can be caused either by mitochondrial genes with coupled nuclear genes or by nuclear genes alone
the resulting conditions are known as cytoplasmic male sterility (CMS) and genic male sterility (GMS), respectively. Plants possess mitochondrial genomes that are large and complex compared to animals. Plant mitochondrial genomes range between 200 - 2,000 kbp.

[#957] The alternative forms of a gene are called
Correct Answer

(C) Alleles

Explanation

Solution: The alternative forms of a gene are called Alleles. "Allele" is the word that we use to describe the alternative form or versions of a gene. Alleles are matching genes
one from our biological mother, and one from our biological father. One has two copies of every gene (strings of code that drive some biological function on our chromosomes). They can be identical, but they can often have slight differences.

[#958] Match the following columns: Column I Column II a. Magnesium 1. Found in middle lamella b. Sulphur 2. A structural component of chlorophyll c. Calcium 3. Required for enzymatic activity d. Manganese 4. Found in some amino acids
Correct Answer

(A) a-2, b-4, c-1, d-3

Explanation

Solution: a. Magnesium is a structural component of chlorophyll. The chlorophyll molecule consists of a central magnesium atom surrounded by a nitrogen-containing structure called a porphyrin ring
attached to the ring is a long carbon-hydrogen side chain, known as a phytol chain. b. Sulphur is found in some amino acids. Methionine, cysteine, homocysteine, and taurine are the 4 common sulfur-containing amino acids. c. Calcium is found in the middle lamella. The middle lamella is a layer that cements together the primary cell walls of two adjoining plant cells. The middle lamella is made up of calcium and magnesium pectate. d. Manganese is required for enzymatic activity. Manganese (Mn) is an essential element that is involved in the synthesis and activation of many enzymes and the regulation of the metabolism of glucose and lipids in humans.

[#959] In plant breeding, undesirable linkages can be broken by
Correct Answer

(D) All of these

Explanation

Solution: In plant breeding, undesirable linkages can be broken by Recurrent selection, Disruptive mating, and Diallele, selective mating. Recurrent selection means repeated cycles of selection and breeding aimed at the gradual genetic improvement of a few key traits in a single species. Disruptive selection with assortative mating can lead to two reproductively isolated populations, but with random mating, it can lead only to polymorphism
the population will never diverge into two genetically isolated populations. A diallel cross is a mating scheme used by plant and animal breeders, as well as geneticists, to investigate the genetic underpinnings of quantitative traits.

[#960] In humans apoptosis occurs in except
Correct Answer

(B) In cells damaged by injury

Explanation

Solution: In humans, apoptosis occurs except in cells damaged by injury. Apoptosis is the process of programmed cell death. It is used during early development to eliminate unwanted cells
for example, those between the fingers of a developing hand. Apoptosis occurs normally during development and aging and as a homeostatic mechanism to maintain cell populations in tissues. In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair. Apoptosis also plays a role in preventing cancer.