Biology MCQs

Notes:
Lymphocytes are a type of white blood cell that are part of the immune system. Their main function is to produce antibodies that protect the body from foreign invaders, such as viruses, bacteria, and toxins. These antibodies help the body respond to and eliminate foreign invaders, which provides protection against infectious diseases.
Lymphocytes also help the body’s immune system remember every antigen it comes in contact with. After an encounter, some lymphocytes turn into memory cells.
There are two main types of lymphocytes: B cells and T cells. B cells produce antibodies that attack invading bacteria, viruses, and toxins. T cells destroy the body’s own cells that have been taken over.
If you have low numbers of lymphocytes (lymphopenia), you are at higher risk of infection. Symptoms can range from mild to serious and are correlated to the severity of the lymphopenia as well as its duration. Some people have no symptoms.

Notes:
Chlorophyll, the photosynthetic pigment that gives plants their green color, is present in Algae, Ferns and Mosses, thus enabling them to convert sunlight to chemical energy through photosynthesis. Although fungi are a group of organisms often thought to be plants, they lack chlorophyll, and hence, they are non-photosynthetic, surviving instead on organic matter.

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Fructose is a form of carbohydrate synthesized in plants. It becomes table sugar by combining with glucose. It is a simple ketonic monosaccharide found in many plants.

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Rafflesia is a genus of parasitic flowering plants in the family Rafflesiaceae. It is the plant with largest flowers and found in many parts of the South East Asia.

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Ribulose-1,5-bisphosphate carboxylase oxygenase first enzyme of Calvin Cycle of Carbon Fixation

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Thymine is the nitrogenous base that is present in DNA but not in RNA. Thymine is a pyrimidine base that pairs with adenine through hydrogen bonding in DNA. In RNA, thymine is replaced with uracil, which pairs with adenine.
The four nitrogenous bases in DNA are adenine, guanine, cytosine, and thymine. The four nitrogenous bases in RNA are adenine, cytosine, guanine, and uracil.

Notes:
Birds evolved from theropod dinosaurs during the Jurassic around 165–150 million years ago. Birds aren’t just closely related to dinosaurs, they really are dinosaurs! This is what most people mean when they say that birds are reptiles, although technically according to the phylogenetic system mammals are also reptiles.

Notes:
Identical twins form when one egg has been fertilised by one sperm and the zygote splits into two. This happens at the very earliest stage of development, when the zygote is no more than a cluster of a few cells.  If this egg then splits into two, an identical twin pregnancy can result.

Notes:
The genus of the human being today is called Homo and the man today is called as Homo sapiens. From simple life forms that were unicellular to the development of multicellular organisms gave rise to the vertebrates. The family to which human beings belong is called Hominidae. It was in the Miocene age that the family Hominidae split from the Pongidae(apes) family.

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Mammology is a branch of biology that deals with the study of mammals.