Biology MCQs

Notes:
A neuron or nerve cell is a cell that carries electrical impulses. Neurons are the basic units of the nervous system. Every neuron is made of a cell body (also called a soma), dendrites and an axon. Dendrites and axons are nerve fibers. It is the longest cell of human body.

Notes:
Biological sex is determined by a pair of sex chromosomes: XY in males and XX in females. Genes on the X chromosome are said to be X-linked. X-linked genes have distinctive inheritance patterns because they are present in different numbers in females (XX) and males (XY).Thus usually occurs as soon as conception takes place.

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The word latex means only natural rubber. Natural rubber is made from the white sap of some trees such as the Hevea brasiliensis (Euphorbiaceae). Other elastomers, called synthetic rubbers, are made by chemical processes.

Notes:
Adipose tissue that’s fat cells which are under the skin act as barrier to loss of the heat from the body and it protects the skin from entering of highly reactive UV rays of the sun. Fat present below the skin surface in our body, act as an insulator against loss of heat from the body. The deposited fat works as barrier, which prevents loss of heat.

Notes:
The clavicle or collarbone is a long bone that serves as a strut between the shoulder blade and the sternum or breastbone. There are two clavicles, one on the left and one on the right. The clavicle is the only long bone in the body that lies horizontally.
The patella, also known as the kneecap, is a flat, circular-triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint.
The scapula, or shoulder blade, is a large triangular-shaped bone that lies in the upper back.
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury.

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Insulin is a protein chain or peptide hormone. There are 51 amino acids in an insulin molecule. It has a molecular weight of 5808 Da. Insulin is produced in the islets of Langerhans in the pancreas.

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The single most factor responsible for the cpolour of the skin is the pigment melanin. It is secreted by the melanocytes within the skin.

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Inputs of photosynthesis are carbon dioxide and water and outputs are glucose and oxygen. Photosynthesis occurs in the presence of sunlight.

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Phloem, also called bast, are tissues in plants that conduct foods made in the leaves to all other parts of the plant. This transport process is called translocation. Phloem is composed of various specialized cells called sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells.

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Virology, the branch of microbiology that deals with the study of viruses.