Biology Test - 9

The common fungicide used in preventing growth of fungus on herbarium specimens is mercuric chloride.

It is highly toxic compound that volatilizes slightly at ordinary temperature and appreciably at 100 degrees Celsius. Mercuric chloride is corrosive to mucous membranes and used as a topical antiseptic and disinfectant.

The correct matched is(ii), (iv), (iii), (v).

Microbes are used in production of several household and industrial products:

Lactobacillus - Production of curd

Saccharomyces cerevisiae - Bread making

Aspergillus niger - Citric acid production

Acetobacter aceti - Acetic acid.

In recombinant DNA technology bacteria is able to produce human insulin because genetic code is nearly universal, that is all contain same nitrogen bases, that is A, G, C, and T.

The gene for human insulin is inserted into the gap in the plasmid. This plasmid is now genetically modified. The genetically modified plasmid is introduced into a new bacteria or yeast cell. This cell then divides rapidly and starts making insulin.

The anther is a terminal bilobed structure and the wall of the anther consist of the following layers:

Endothecium: The cell of the endothecium layer has α-cellulosic fibrous bands arising from the inner tangential wall which help in the dehiscence of anther due to its hygroscopic nature. They are absent in hydrophytes.

Epidermis: It is the outermost, singled layered and protective function. The epidermis of Arceuthobium(parasite) develops some fibrous thickenings and is called exothecium.

Middle layer: Cells of this layer are ephemeral and are 1 to 3 layered, which degenerate at maturity.

Tapetum: It is the innermost layer of the anther wall which surrounds the sporogenous tissue. It nourishes the developing pollen grains. The cell of this layer possess dense cytoplasm and generally have more than 1 nucleus and show an increase in DNA content.

Collagen is the main structural protein of the various connective tissues in animals. These are secreted by fibroblast cells. It appears, in the form of elongated fibrils and is mostly found in fibrous tissues, such as tendons, ligaments and skin. The fibroblast is the most common cell that creates collagen.

Cuboidal epithelium with brush border of microvilli is found in proximal convoluted tubule (PCT) of nephron.

A brush border is the microvilli-covered surface of simple cuboidal epithelium and simple columnar epithelium cells found in certain locations of the body. The brush borders of the small intestinal lining are the site of absorption.

Different types of population fluctuation are:

• Flat type
• Cyclic type
• Seasonal type
• Annual type

In population ecology: Population fluctuation.  populations rarely grow smoothly up to the carrying capacity and then remain there. Instead, fluctuations in population numbers, abundance, or density from one time step to the next are the norm. Population cycles make up a special type of population.

Abducentis not considered as the purely afferent nerve.

Cranial nerves Olfactory, Optic and Vestibulocochlear are considered purely afferent in the nervous system.Abducent is the 6th cranial nerve which is considered as purely efferent nerve.The afferent nerves receive signal from a sensory organ and sent it to CNS for processing.

To produce enzyme in large quantity equipment required are bioreactors, that is large scale production involves use of bioreactors.

Bioreactor systems are a vital component in the process of 3D tissue engineering and the formation of tissue constructs. Bioreactors are used to provide a tissue-specific physiological in vitro environment during tissue maturation. Based on the bioreactor technology, various tissue systems can be incubated in vitro.

Mitochondria storage energy in the form of ATP molecules & also responsible for cellular respiration.

Mitochondrion, membrane-bound organelle found in the cytoplasm of almost all eukaryotic cells (cells with clearly defined nuclei), the primary function of which is to generate large quantities of energy in the form of adenosine triphosphate (ATP). Mitochondria are typically round to oval in shape and range in size from 0.5 to 10 μm. In addition to producing energy, mitochondria store calcium for cell signaling activities, generate heat, and mediate cell growth and death.

This cell organelle is known as the “Power House of The Cell”. The main functions of cellular respiration are storge energy in the form of ATP molecules.