Biology Test - 26

Small pox diseases first successful vaccination was devloped (it is caused by Variola virus).

The smallpox vaccine, introduced by Edward Jenner in \(1796\) , was the first successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox did not catch smallpox and showed that inoculated vaccinia protected against inoculated variola virus.

The hormone released from testes is Testosterone. Testosterone is the male sex hormone. It plays a key role in the development of male reproductive tissues such as the testis and prostate. It also increases the growth of body hair.

Breakdown of complex molecules to yield energy takes place in Cytoplasm and mitochondria.

All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm. The portion of the cytoplasm that is not contained in the organelles is called the cytosol. Although cytoplasm may appear to have no form or structure, it is actually highly organized.

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).

Lysosomes is Referred to as “Suicidal Bags” of the Cell.

Lysosomes are sphere-shaped sacs filled with hydrolytic enzymes that have the capability to break down many types of biomolecules. Lysosomes are known as suicide bags of the cell because they contain lytic enzymes capable of digesting cells and unwanted materials. autolysis and burst open when the cell is damaged. This causes the hydrolytic enzymes to be released. The released enzymes then digest their own cell, causing the cell to die. As a result, they’re known as cell suicide bags.

Tendon is a strong, dense inextensible connective tissue with parallel collagen fibres that connect a muscle with bone.

Tendons are formed by thick bundles of collagen fibers running parallel to each other. So, they are called dense regular connective tissue. The fibrocytes are arranged in neat rows. The parallel arrangement is such that it runs along the lines of stress. They are strong but not very flexible. Tendons join the skeletal muscles to the bones.

Statements a, b and c are correct.

Most of the fishing grounds occur in areas where the continental shelf is wide.Fishing activity is well developed in warm tropical waters since the availability of nutrients.Mixing of warm and cold currents brings plant nutrients for fish.Thus, statement a,b and c are correct.

Marine fisheries are more significant than other types in India.Therefore, statement d is not correct.

Increased number of number mitosis may be present in the following tissue except nails.

An increased number of cells in mitosis means that the cells are dividing faster than cells in roots with a lower number of cells. This is because, with an increased number of cells, there is more activity at a more rapid rate.

The correct matching codes are: a - 1, b - 3, c - 2

• Plasma cells are differentiated B-lymphocyte white blood cells capable of secreting immunoglobulin, or antibody. These cells play a significant role in the adaptive immune response, namely, being the main cells responsible for humoral immunity.
• In immunology, a memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system. These cells develop within germinal centers of the secondary lymphoid organs. 
• After activation by antigens, the B cells divide rapidly, with the same binding site as the starting B cell. The activated B cells differentiate into plasma B cells, which have a powerful ability to secrete antibody.

Androgens and Oestrogen are shormones control the sexual behaviour.

Androgenis the anabolic steroidresponsible for the embryonic development of male sexual organs and secondary sexual characteristics at puberty(Male sex hormone).

• Androgen primarily is a male sex hormone but females also have androgen at a lower limit.
• Androgen is primarily produced in the testes, adrenal cortex, and ovaries.
• There are several types of androgen-like DHEA, A4, A5 and DHT.

Oestrogenis the female sex hormone responsible for the development and regulation of female sex organs and secondary sex characteristics.

• It is the primary female sex hormone but is minimally observed in males.
• Oestrogens levels are at their peak in women in their reproductive age.
• The primary production sites of estrogen during pregnancy are the ovaries and the placenta.

Hotspots are areas with high density of biodiversity or mega diversity which are also the most threatened ones. Ecologically hotspots are determined by four factors - number of species/ species diversity, degree of endemism, degree of threat to habitat due to its degradation and fragmentation, and degree of exploitation. India has three hotspots : Indo-Burma, Himalayas and Western Ghats - Sri Lanka. India is even otherwise a country of mega diversity with 2.4% of land area and having 8.1% of global diversity. Major centres of biodiversity are Agasthyamalai hills, Silent valley and Amambalam reserve. There is high degree of endemism as well as richness of species of flowering plants, amphibians, reptiles, some mammals and butterflies.