Biology MCQs

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TB is bacterial disease caused by “Mycobacterium tuberculosis” bacteria that most often affect the lungs. The disease is spread from person to person through the air. It commonly affects the lungs but can also affect other parts of the body. It is the second biggest killer disease worldwide next only to HIV/AIDS. It can be completely cured with proper and regular medication

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“Survival of the fittest” is a phrase that originated from Darwinian evolutionary theory as a way of describing the mechanism of natural selection. The biological concept of fitness is defined as reproductive success.

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Blue whales are the largest animals ever known to have lived on Earth. These magnificent marine mammals rule the oceans at up to 100 feet long and upwards of 200 tons.

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Biogas or Gobar gas is produced by the breakdown of organic matter in the absence of oxygen. It can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste. It is a renewable energy source. It comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes. It is produced by anaerobic digestion.

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Pasteurization is the process of heating milk up and then quickly cooling it down to eliminate certain bacteria and all other microorganisms. More common is heating milk up to at least 161.6 degrees Fahrenheit for 15 seconds. There are following methods that are most commonly used:
• High Temperature, Short Time (HTST) method – This method requires that the milk be held at 161 degrees for 16 seconds.
• Ultra-Pasteurization (UP) – This is the type of pasteurization that you will most commonly see on cartons of milk, half-and-half and heavy cream.

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Any legume plants will help in nitrogen fixation. Beans contain symbiotic bacteria called Rhizobia within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants. When the plant dies, the fixed nitrogen is released, making it available to other plants and this helps to fertilize the soil.

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• If you are colorblind, you have difficulty distinguishing certain colors, such as blue and yellow or red and green. Color blindness is an inherited condition that affects males more frequently than females
• Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern. The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder.
• Sickle cell anemia is inherited as an autosomal recessive condition. This means that the gene can be passed on from a parent carrying it to male and female children.

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Mitochondrion is the organelle in the cell, other than nucleus that contains DNA. Mitochondria are the working organelles that keep the cell full of energy. Mitochondria are small organelles floating free throughout the cell. Some cells have several thousand mitochondria while others have none. Muscle cells need a lot of energy so they have loads of mitochondria.

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The octopus is a soft-bodied, eight-limbed mollusc of the order Octopoda. Around 300 species are recognised, and the order is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids.

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AIDS is a viral disease. In this disease the immune system weakens and the body becomes prone to different type of infection by pathogens. Sweating at night, swollen lymph nodes, loss of memory and loss of weight are also symptoms of AIDS.