Biology Test - 51

The commonly cultivated varieties of lady's finger are Kamini, Pusa Mukhamali, Parbhani Kranti, Pusa Sawani, Vaishali, Vagmi, Padmini etc.

Pusa Gaurav is an insect-resistant variety of Rapeseed mustard that shows resistance against aphids.

Pusa Sem 2, Pusa Sem 3 is an insect-resistant variety of Flat bean that shows resistance against jassids, aphids and fruit borer.

TCA cycle is also known as Krebs cycle.

Tricarboxylic acid cycle, (TCA cycle), also called Krebs cycle and citric acid cycle, the second stage of cellular respiration, the three-stage process by which living cells break down organic fuel molecules in the presence of oxygen to harvest the energy they need to grow and divide.

In all organisms except bacteria the TCA cycle is carried out in the matrix of intracellular structures called mitochondria.

Matrix potential is the energy developed due the attachment of water with non-dissolved solutes such as soil.  It is of negligible value. Matric potential (Ψm) is the amount of water bound to the matrix of a plant via hydrogen bonds and is always negative to zero. In a dry system, it can be as low as –2 MPa in a dry seed or as high as zero in a water-saturated system. Whereas water potential is the ultimate energy and solute potential and pressure potential are important components of water potential.

The first living cells on Earth most likelywere heterotrophs.

Oxygen comes from autotrophs, organisms that make their own food through photosynthesis. Because there was no oxygen in Earth’s early atmosphere, the first cells must have been heterotrophs, organisms that take their food from the surrounding environment.

The brain stem does not include the cerebellum.

The brainstem (brain stem) is the distal part of the brain. It contains the midbrain (mesencephalon), the pons, and the medulla oblongata. The brainstem does not include the cerebellum which is part of the hindbrain.

The term 'clone' cannot be applied to offspring formed by sexual reproduction because offspring do not possess exact copies of parental DNA. Cloning is the process of producing genetically identical individuals of an organism either naturally or artificially. During sexual reproduction, fertilization creates a single-celled zygote which includes genetic material from both gametes.

Nitrogenous waste products are eliminated mainly as ammonia in tadpole and urea in adult frog.

Ammonia is highly soluble in water, so in aquatic animals e.g., tadpoles of frog, the nitrogenous waste products are excreted in the form of ammonia. In terrestrial animals e.g., adult frog, these wastes are excreted in the form of urea.

The test cross, invented by Mendel, is a deliberate genetic cross between an individual of unknown genotype (homozygous dominant or heterozygous) for a dominant phenotype, and a homozygous recessive individual. Deliberate genetic crosses are not possible in studying human inheritance. They would be both immoral and unethical, and the waiting time for results would be too long. Patterns of inheritance in humans are studied retrospectively, by constructing family pedigrees, as was illustrated in problems 1, 4, 5, and 10 of this problem set.

Jhum cultivation, also known as the slash and burn agriculture, is the process of growing crops by first clearing the land of forests and burning them thereafter. It is also known as shifting agriculture. The burnt soil contains potash which helps in increasing the nutrient content of the soil. This process has led to the maximum damage to the Indian forests as they are cleared for this process.

Marasmus is a disorder caused by a deficiency of food or protein. Marasmus occurs in infants below 1 year of age when they do not get sufficient mother's milk or weaning diet. Such infants are often provided with very diluted cow or buffalo milk. Marasmus babies have emaciated bodies with shriveled appearance, thin face, sunken eyes, wrinkled thin and dry skin, protruding ribs, reduced digestion, and frequent diarrhea.