Which of the following crops typically shows a very high degree of inbreeding depression upon self-pollination?
Sorghum
Alfalfa
Pearl millet
Sunflower
✓
Correct Answer: Alfalfa Alfalfa (Medicago sativa) is a naturally cross-pollinated legume that experiences significant loss of vigor and productivity (inbreeding depression) when inbred (self-pollinated). Sorghum and pearl millet are often cross-pollinated but show less depression, while sunflower shows moderate depression.
Which of the following chemicals is commonly used for testing seed viability through a biochemical staining method?
Tetrazolium chloride
Ether
Thiourea
Benzene
✓
Correct Answer: Tetrazolium chloride The tetrazolium test uses 2,3,5-triphenyl tetrazolium chloride (TTC). Living, respiring tissues in the seed embryo reduce the colorless TTC to a red-colored insoluble compound called formazan, visually indicating viability. Non-viable tissues remain unstained.
In the Indian seed certification system, what is the color of the official tag attached to bags of Foundation Seed?
White
Green
Blue
Golden yellow
✓
Correct Answer: White Foundation Seed, which is the progeny of Breeder Seed, is required to have a White color certification tag according to the standards set under the Indian Seeds Act.
Maximum heterosis (hybrid vigor) is generally manifested in which type of hybrid cross?
Single cross (A x B)
Double cross ((A x B) x (C x D))
Three-way cross ((A x B) x C)
Top cross (Inbred x Variety)
✓
Correct Answer: Single cross (A x B) A single cross hybrid, produced by crossing two distinct homozygous inbred lines, usually exhibits the highest level of heterosis because it maximizes the heterozygosity and combination of favorable dominant genes in the F1 generation.
Commercial hybrid varieties utilizing Cytoplasmic Male Sterility (CMS) were first successfully developed in which crop?
Sorghum
Maize
Onion
Castor
✓
Correct Answer: Onion Although hybrid vigor was recognized early in maize, the first large-scale commercial production of hybrid seeds using a practical Cytoplasmic Male Sterility (CMS) system was achieved in onions by Henry Jones in the 1940s.
The amphidiploid species *Brassica juncea* (Indian mustard) evolved through natural hybridization between which two diploid species?
*Brassica campestris* x *Brassica napus*
*Brassica campestris* x *Brassica nigra*
*Brassica carinata* x *Brassica nigra*
*Brassica nigra* x *Brassica oleracea*
✓
Correct Answer: *Brassica campestris* x *Brassica nigra* *Brassica juncea* (AABB genome) is an allotetraploid that originated from an interspecific cross between *Brassica rapa* (syn. *B. campestris*, AA genome) and *Brassica nigra* (BB genome), followed by chromosome doubling. This relationship is depicted in the 'Triangle of U'.
The pure-line theory, stating that selection within a genetically pure line is ineffective, was proposed by:
John
Mendel
Johannsen
Swaminathan
✓
Correct Answer: Johannsen Wilhelm Johannsen, a Danish botanist, proposed the pure-line theory around 1903 based on his work with self-pollinating beans. He demonstrated that variation within a pure line (homozygous individuals) is environmental, and selection within it does not alter its genetic makeup.
MPMH17, RHB223, MPMH21, and RHB224 are popular recommended hybrid varieties of which crop?
Maize
Sorghum
Cotton
Bajra (Pearl Millet)
✓
Correct Answer: Bajra (Pearl Millet) These designations (MPMH - Mandor Pearl Millet Hybrid, RHB - Rajasthan Hybrid Bajra) represent high-yielding hybrid varieties of Bajra (Pearl Millet - *Pennisetum glaucum*), commonly grown in India, particularly in arid and semi-arid zones like Rajasthan.
A tall plant (T dominant) is crossed with a dwarf plant (t recessive). The progeny shows approximately a 1:1 ratio of tall to dwarf plants. What are the likely genotypes of the parents?
TT x tt
Tt x Tt
Tt x tt
tt x tt
✓
Correct Answer: Tt x tt A 1:1 phenotypic ratio (Tall:Dwarf) is characteristic of a test cross involving a heterozygous parent (Tt) and a homozygous recessive parent (tt). The Tt parent produces T and t gametes; the tt parent produces only t gametes, resulting in Tt (Tall) and tt (Dwarf) offspring in equal proportions.
In older soil classification systems (e.g., Baldwin, Kellogg, Thorp), which of these great soil groups belongs to the Zonal soil order?
Laterite soils
Alluvial soils
Saline soils
Regosols
✓
Correct Answer: Laterite soils Zonal soils were defined as mature soils reflecting the primary influence of climate and vegetation. Laterite soils, formed under intense weathering in humid tropical/subtropical climates, were classified as Zonal. Alluvial soils (Azonal) are young and dominated by parent material, while Saline soils (Intrazonal) are influenced by local factors.
Note: We try our best to be correct, but there might be typos or mistakes. If you spot any, kindly let us know. Thanks❤️ Feedback:- We welcome your thoughts after reading this post. Please share any feedback that could help us improve the website for a better experience here: [Click here]
by
my Name Manoj Verma hai sir hindi me kese