Biology: CUET Mock Test - 6 - Class 12 MCQ

Mesic means an area having a moderate or well-balanced supply of moisture. The hydrarch, as well as xerarch succession finally leads to the formation of a mesic community. It is neither to wet nor too dry.

The habitat having an excess of hydration is known as a hydric habitat. They have wet soils and are characterized by an abundance of moisture. Wetland area is an example of a hydric habitat.

The first biotic community to invade a bare land or area is known as the pioneer community. In a xerarch succession, lichens in the temperate region act as pioneering species. Some examples of lichens are Rinodina, Lecanora, Parmelia, etc.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. In a xerarch succession, the pioneering species lichens release acids to dissolve rocks. This helps in weathering and soil formation.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. The mosses are replaced by the herbaceous plants in a xerarch succession. Some examples of xeric grasses are Aristida, Solidage, Poa, etc.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. The shrub stage is replaced by a forest in a xerarch succession. The trees found in the forest are Acacia, Prosopis, Boswellia, etc.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. It occurs in an area where there is less amount of moisture. It is mostly observed in the desert area.

Ecological succession is the gradual change in the species composition of a given area which can be predicted. Biomass is the total organic material required for energy production.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. It mostly starts with the invasion of lichens and ends with the formation of the forest. The pioneering species grow with time leading to a formation of a climax community called a forest.

The changes in the community are constant, orderly and sequential. These changes lead to the formation of a stable, self-perpetuating and final biotic community that developed during the end of biotic succession known as a climax community.

The first biotic community to invade a bare land or area is known as the pioneer community. These are the organisms of the first seral stage. They further grow and expand to form a climax community.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. The herbaceous plants are replaced by the shrubs in a xerarch succession. Some examples of shrubs are Phytocarpus, Rhus, etc.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. In a xerarch succession, the pioneering species lichens release acids to dissolve rocks. This helps in weathering and soil formation.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. The pioneering species lichens are replaced by mosses in a xerosere. Some examples of mosses are Tortula, Grimmima, Polyerichum, etc.

The sequence of successional stages occurring on bare rocks is known as xerarch succession. It is also known as xerosere and starts in a newly formed rocky area.

The habitat having too much dryness is known as a xeric habitat. It is deficient in moisture and is characterized by limited water availability. Desert region is an example of a xeric habitat.

Recombinant therapeutics is the type of medicines obtained from recombinant organisms. These are mostly protein in nature. Till date, 30 recombinant therapeutics have been approved for human use which includes insulin, human factor IX, etc.

In early days the insulin was obtained from the pancreas of cattle and pigs. Insulin obtained this way had many disadvantages. Nowadays insulin is obtained using recombinant DNA technology. For this microorganisms are used.

The polypeptide chains present in insulin is connected by disulphide bonds. These disulphide bonds are formed between two cysteine residues. In total insulin consists of 3 disulphide bonds.

Insulin is a pro-hormone secreted in mammals by the pancreas. This pro-hormone need to be processed to become a fully mature and functional hormone. Insulin allows the absorption of glucose I blood.

C-peptide is absent in mature insulin. This connecting peptide connects A and B chain in pro-insulin. It is removed during the maturation of pro-insulin to insulin.

The first recombinant insulin was constructed by using E.coli. It was developed by Lilly Company. E.coli was used because it has a large circular plasmid that can act as a vector, requires less growth time and can be easily grown in a laboratory.

C-peptide is removed during the maturation phase of insulin production. C-peptide consists of 30 amino acids and it joins two insulin polypeptide chains in pro-insulin. It is released as a by-product of insulin formation.

In 1983 Lilly Company of America that was founded by Eli Lilly used recombinant DNA technology to produce insulin. This insulin was obtained from a microorganism.

The pro-hormone form of insulin consists of an extra stretch called C-peptide. The C peptide is a connecting peptide having approximately 31 amino acids. It connects A and B chain of pro-insulin.

Insulin is secreted by the pancreas. The stomach secretes various digestive enzymes like pepsin and gastric juice. The thyroid secretes thyroid hormones while small intestine secretes trypsin.

Insulin consists of two polypeptide chains. These are known as A chain and B chain. A chain is made up of 21 amino acids while the B chain is made up of 30 amino acids. Thus, making insulin a polypeptide containing 51 amino acids.

Out of 30 how many recombinant therapeutics 12 have been marketed in India. These products have been approved by the Genetic Engineering Appraisal Committee (GEAC). Few examples of approved products are Human growth hormone, Human insulin, Erythropoietin, etc.

Plasmids and bacteriophages can replicate within bacterial cells without the help of chromosomal DNA. Thus they are self-replicating and autonomous in nature. They have their own replication machinery.

Bacteriophages or simply phages are the viruses that infect bacteria. They are self-replicating in nature. Archaea is a domain of bacteria. pUC is a vector.