Biology Test - 53

The efficiency of the transfer of energy along the food chain from one trophic level to another is generally less than 10% as 90% of energy is lost as heat. This is in accordance with the 10% law.

The 10% law of transfer of energy from one trophic level to the next was introduced by Raymond Lindeman (1942). According to this law, during the transfer of organic food energy from one trophic level to the next higher level, only about 10% of the transferred energy is stored as flesh.

Haptotropismis a directional growth movement which occurs as a mechanosensory response to a touch stimulus. Haptotropismis typically found in twining plants and tendrils, however plant biologists have also found haptotropic responses in flowering plants and fungi.

The cerebellum (which is Latin for “little brain”) is a major structure of the hindbrain that is located near the brainstem. This part of the brain is responsible for coordinating voluntary movements.

Coordination of voluntary movements: Most movements are composed of a number of different muscle groups acting together in a temporally coordinated fashion. One major function of the cerebellum is to coordinate the timing and force of these different muscle groups to produce fluid limb or body movements. Therefore, people drinking alcohol heavily have problems walking straight and driving.

The full form of DNA is deoxyribonucleic acid which is an organic compound that has a unique molecular structure. It is present in all prokaryotic cells as well as eukaryotic cells. DNA is composed of repeating units of deoxyribonucleotides.Each DNA strand comprises repeating nucleotides. Each nucleotide has phosphate and also sugar that is a pentose group attached lengthwise and a nitrogenous base (Adenine, Guanine, cytosine and thymine) attached to the sugar.

A nucleotide is the basic building block of nucleic acids. RNA and DNA are polymers that are made up of long chains of nucleotides.

Polyploidy is a condition in which the cells of an organism have more than two paired (homologous) sets of chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes—one set inherited from each parent. Polyploid is especially common in plants.

Adrenaline hormone does not belong to the reproductive system.

Adrenaline:

This hormone is secreted by the adrenal glands in the centre of the medulla. The main function of adrenaline is to produce contraction of the spleen so as to store the blood, increase heartbeat and sweating, reduce the blood clotting period, and pupillary dilation.

Progesterone hormone:

Progesterone is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called progestogens and is the major progestogen in the body.

Estrogenhormone:

Estrogen, or oestrogen, is a category of sex hormones responsible for the development and regulation of the female reproductive system and secondary sex characteristics.

Testosteronehormone:

Testosterone is the primary sex hormone and an anabolic steroid in males. In male humans, testosterone plays a key role in the development of male reproductive tissues such as the testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.

Broca area also called convolution of Broca, a region of the brain that contains neurons involved in speech function. This area, located in the frontal part of the left hemisphere of the brain, was discovered in 1861 by French surgeon Paul Broca, who found that it serves a vital role in the generation of articulate speech. That's why after meeting an accident Anita became very poor in grammar and pronunciation.

Rice bean (Vigna umbellata) is a tropical to temperate grain legume primarily grown for food, especially in Asia. Rice bean seeds and vegetative parts are also used for fodder.Vigna umbellata is a short-lived perennial legume usually grown as an annual. It has a very variable habit: it can be erect, semi-erect, or twining. It is usually 30-100 cm in height but can grow up to 200 cm.

The amount of water lost by plants due to transpiration and guttation is approximately 98%. Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97.5-98% is lost by transpiration and guttation. Watermelon contains 92% of water. Herbs have 12% of their fresh weight as the dry matter. Mustard plant absorbs water having 50% of their weight in 5 hours.

The operon created is a fused operon with the regulatory genes of the lac operon and structural genes of trp operon. So, expression of trp structural genes will be under the regulation of lac regulatory genes. It is no longer under the regulation of tryptophan presence or absence. Expression of the lac operon occurs when lactose is present and glucose is absent. Presence of glucose suppresses the lac operon by catabolite repression.