Biology Test 127

1. Collection of genetic variability- Genetic variability from various wild varieties, species, and relatives of crop species are collected to maintain the genetic diversity of a species. Germplasm collection is the entire collection of the diverse alleles of a gene in a crop.

4. Evaluation of germplasm and selection of parents- The germplasm collected is then evaluated to identify plants with a desirable combination of characters. The selected plants with the desired genes are then used as parents in plant breeding experiments and are multiplied by the process of hybridization.

2. Cross-Hybridization among Selected Parents- Cross Hybridization combines the desirable characters present in two different parents to produce hybrids. It is a time consuming and tedious job as one has to ensure that the pollen grains collected from the male parent reach the stigma of the female parent. It is not certain that the hybrids would combine desired characters.

5. Selection of superior hybrids- It involves the selection of those plants that have the desired character combination among the progeny of the hybrids. The selection process through scientific evaluation yields plants that are superior to both the parents. The selected progenies are then self-pollinated for several generations to ensure homozygosity.

3. Testing, release, and commercialization of new cultivars- The selected progenies are evaluated for characters such as yield, resistance to diseases, performance, etc. Testing of hybrid variety is done in a farmer's field after evaluation. The release of tested material is done in bulk after selection and certification.

Hence, the correct option is (B).

The integrative plasmids may be replicated and stably maintained in a cell through multiple generations, but at some stage, they will exist as an independent plasmid molecule.

A few types of plasmids can also insert into the host chromosome, and these integrative plasmids are sometimes referred to as episomes in prokaryotes. Plasmids almost always carry at least one gene.

Hence, the correct option is (D).

Duplicated ureter or Duplex Collecting System is a congenital condition in which the ureteric bud, the embryological origin of the ureter, splits (or arises twice), resulting in two ureters draining a single kidney. It is the most common renal abnormality, occurring in approximately 1% of the population.

Hence, the correct option is (D).

The pituitary gland, or hypophysis, is an endocrine gland, about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypophysis rests upon the hypophysial fossa of the sphenoid bone in the center of the middle cranial fossa and is surrounded by a small bony cavity (sella turcica) covered by a dural fold (diaphragma sellae).

Hence, the correct option is (D).

Bone-shaped sclerenchymatous cells found in hypodermal layers of some seeds and fruits are called Osteosclereids. Osteosclereids are a type of sclereids that are bone-shaped or columnar with swollen ends, present in the subepidermal covering of some legume seeds.

Hence, the correct option is (D).

The high energy radiations, salts of heavy metals, CO and protein poisons like cyanides, make protein inactive by the sudden change in pH. Heavy metal toxicity has proven to be a major threat and there are several health risks associated with it. The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning. 

Hence, the correct option is (C).

The simple equation for lactic acid fermentation is glucose ---glycolysis---> 2 pyruvate ---fermentation--> 2 lactic acid. That is to say that glucose is broken down by glycolysis into 2 pyruvates, and then those pyruvates are fermented to produce 2 lactic acid molecules.

Hence, the correct option is (D).

Snakes have no eyelids. Each eye is covered with a single, transparent scale. These eye scales protect the eyes from mechanical damage and prevent the eyes from drying out, just as an eyelid would do. In effect, snakes developed another solution to protect their eyes.

Hence, the correct option is (A).

Phytoplankton < Zooplankton < Smelt < Lake trout < Herring gull is the correct order. Heavy metals, which have widespread environmental distribution and originate from natural and anthropogenic sources, are common environmental pollutants. In recent decades, their contamination has increased dramatically because of continuous discharge in sewage and untreated industrial effluents. Because they are non-degradable, they persist in the environment; accordingly, they have received a great deal of attention owing to their potential health and environmental risks. The concentration depends upon the quantity of metal consumed and environmental conditions.

Hence, the correct option is (D).

An allergy to cow's milk and related dairy products affects one in 50 in babies and is different to lactose intolerance. Very few adults are allergic to cow's milk. People who are allergic to cow's milk can also be allergic to milk from other animals such as goats, sheep and buffalo.

Hence, the correct option is (A).