Biology MCQs

Notes:
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the sub-phylum Medusozoa. Jellyfish do not have specialized systems for osmoregulation, respiration and circulation, and do not have a central nervous system.

Notes:
The Nervous system is made up of two types of cells: Glia, which regulate homeostasis, providing support and protection to the function of neurons and Neurons, which transmit signals between them and from one part of the body to another.

Notes:
The spleen, which is located under the ribcage and above the stomach in the left upper quadrant of the abdomen is the largest organ in the lymphatic system. It is that organ where RBC are selectively destroyed/ recycled by macrophages.

Notes:
The Chlorophyll cells within the plant leaves are perfectly optimized to absorb red and blue waves of the Sun Light. Chlorophyll is concentrated within organisms in structures called chloroplasts.

Notes:
Polymerase enzyme plays an important role in adding the building blocks to the primer in a sequence determined by the DNA template. It synthesizes long chains of polymers or nucleic acids.

Notes:
In some plants such as Cactuses, the stem is flattened and green and carries out the function of the leaf. Such a stem, adapted for the manufacture of food is called phylloclade. The leaves here are reduced or modified into spines to lessen the transpiring surface. Phylloclades are adapted for life in dry and arid regions.

Notes:
Rhizobium is a kind of symbiotic bacteria. Many legumes have root nodules that provide a home for symbiotic nitrogen-fixing bacteria called rhizobia. This relationship is particularly common in nitrogen-limited conditions. The Rhizobia convert nitrogen gas from the atmosphere into ammonia.

Notes:
Cereals which are made with puffed or powdered rice and refined wheat typically contain starch. Starch is the most common form of carbohydrate and typically found in staple grains like rice, wheat, and corn.

Notes:
The hypothalamus in the brain controls body temperature by regulating heat production and loss:
Temperature comparison: The hypothalamus compares the body’s current temperature to the normal temperature of around 37°C.
Heat production: If the body is too cold, the hypothalamus triggers heat production.
Heat loss: If the body is too hot, the hypothalamus triggers heat loss, such as sweating or giving off heat.

Notes:
Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen – “organic” referring to materials produced as a result of the human body – and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.