Genetics And Plant Breeding - Study Mode

[#736] The codon for anticodon 3' UAU 5' is
Correct Answer

(B) 5'AUA3'

Explanation

Solution: The codon for anticodon 3' UAU 5' is 5'AUA3'. A codon is a sequence of three consecutive nucleotides in a DNA or RNA molecule that codes for a specific amino acid. An anticodon is a trinucleotide sequence located at one end of a transfer RNA (tRNA) molecule, which is complementary to a corresponding codon in a messenger RNA (mRNA) sequence.

[#737] The term vertical resistance and horizontal resistance were coined by
Correct Answer

(C) Van der Plank (1963)

Explanation

Solution: The terms vertical resistance and horizontal resistance were coined by Van der Plank (1963). The term vertical resistance, used commonly in the context of plant selection, was first used by J. E. Vanderplank to describe single-gene resistance. This contrasted with the term horizontal resistance which was used to describe many-gene resistance. Vertical resistance there are single genes for resistance in the host plant, and there are also single genes for parasitic ability in the parasite. This phenomenon is known as the gene-for-gene relationship, and it is the defining characteristic of vertical resistance.

[#738] Who gave the criteria of essentiality of elements?
Correct Answer

(A) D. L. Arnon

Explanation

Solution: D. L. Arnon gave the criteria for the essentiality of elements. The term essential mineral element (or mineral nutrient) was proposed by Arnon and Stout (1939). They concluded three criteria must be met for an element to be considered essential. The element must be directly involved in plant metabolism. These criteria are important guidelines for plant nutrition but exclude beneficial mineral elements. Beneficial elements are those that can compensate for the toxic effects of other elements or may replace mineral nutrients in some other less specific function such as the maintenance of osmotic pressure.

[#739] The attraction between two similar molecule is
Correct Answer

(A) Cohesion

Explanation

Solution: The attraction between two similar molecules is Cohesion. Cohesion keeps molecules of the same substance together. For plants, cohesion keeps the water molecules together. Surface tension is the effect of intermolecular attraction that causes liquids to form a top or outer layer that behaves like a thin film of sorts. Cohesion causes more water molecules to fill the gap in the xylem as the topmost water is pulled toward the stomata.

[#740] Ploidy level of Gametophyte and Sporophyte are . . . . . . . . and . . . . . . . . , rescpectively.
Correct Answer

(D) n, 2n

Explanation

Solution: Ploidy levels of Gametophyte and Sporophyte are n and 2n respectively. Gametes develop in the multicellular haploid gametophyte. Fertilization gives rise to a multicellular diploid sporophyte, which produces haploid spores via meiosis. This type of life cycle is called a haplodiplontic life cycle.