Genetics And Plant Breeding - Study Mode

[#81] The sunflower seed dormancy is due to
Correct Answer

(D) Ethrel

Explanation

Solution: The sunflower seed dormancy is due to Ethrel. Ethrel is a versatile plant growth regulator which improves colouration and accelerates uniform ripening of fruits. Freshly harvested sunflower seeds are considered to be dormant because they fail to germinate at relatively low temperatures (10°C). This dormancy results mainly from embryo dormancy and disappears during dry storage. Sunflower seed dormancy begins around the third week after pollination and is overcome during storage. It is induced by abscisic acid and broken by ethylene. The dormancy period depends on the genotype and the environmental conditions during maturation and storage.

[#82] The enzyme involved in apoptosis
Correct Answer

(B) Caspases

Explanation

Solution: The enzyme involved in apoptosis is Caspases. Apoptosis is mediated by proteolytic enzymes called caspases, which trigger cell death by cleaving specific proteins in the cytoplasm and nucleus. Caspases exist in all cells as inactive precursors, or procaspases, which are usually activated by cleavage by other caspases, producing a proteolytic caspase cascade.

[#83] What is the most useful method of detecting virus infection in seeds
Correct Answer

(C) ELISA

Explanation

Solution: ELISA is the most useful method of detecting virus infection in seeds. ELISA stands for enzyme-linked immunoassay. The ELISA watershed method is widely used to detect various plant viruses because it is very sensitive. The ELISA method is one of the most popular serology techniques because it is not only sensitive but also easy to do, accurate, simple, and does not require high costs.

[#84] Manganese is a micronutrient because it is
Correct Answer

(B) Required by the plants in small quantities

Explanation

Solution: Manganese is a micronutrient because it is required by plants in small quantities. Micronutrients are essential to plant nutrients that are found in trace amounts in tissue but play an imperative role in plant growth and development. Without these nutrients, plant nutrition would be compromised leading to potential declines in plant productivity. Manganese (Mn) is an important plant micronutrient for plant growth and development and sustains metabolic roles within different plant cell compartments. It is an essential cofactor for the oxygen-evolving complex (OEC) of the photosynthetic machinery, catalyzing the water-splitting reaction in photosystem II (PSII).

[#85] Repressor protein is produced by
Correct Answer

(A) Regulator

Explanation

Solution: Repressor protein is produced by Regulator. A repressor, as related to genomics, is a protein that inhibits the expression of one or more genes. The repressor protein works by binding to the promoter region of the gene(s), which prevents the production of messenger RNA (mRNA). Repressor proteins are essential for the regulation of gene expression in cells. A regulator protein that turns genes ON when it binds DNA is called an activator protein, and a regulator protein that turns genes OFF when it binds DNA is a repressor protein.