Biology Quiz 4

The kidney is the organ that excretes water, fat and various catabolic wastes. The kidneys remove waste products called urea from the blood through tiny filtering units called nephrons. There are about one million nephrons in each kidney.

The approximate time required for a heartbeat is 0.8 second. A normal resting heart rate for adults ranges from 60 to 100 (for children- 70 to 100) beats per minute. (Approximate time required for a heartbeat = 60 second ÷ average heart rate ≈ 0.8 second).

Lichen that grows on the bark is said to be Corticolous. If it is found attached to a rock, it is saxicolous, and if it is found on the ground or soil, it is terricolous.

Green plants are the largest fixator of solar energy. All green plants generate and transfer energy through the processes of photosynthesis and respiration.

Vertebrae is a series of bones that form the spinal column (backbone) of all vertebrates. The average person is born with 33 vertebrae that interact and connect with each other through flexible joints called facets. By the time a person becomes an adult most have only 24-26 vertebrae because some vertebrae at the bottom end of the spine fuse together during normal growth and development.

Barr body is the inactive X-chromosome in the somatic cells of mammalian females. Human females have two X chromosomes, while males have one X and one Y. In all of the female somatic cells, which don't take part in sexual reproduction, one of the X chromosomes is active, and the other is inactivated in a process called lyonization, becoming the Barr body.

BCG (Bacille Calmette-Guerin) is a vaccine for tuberculosis (also known as TB) disease. TB is a serious infection that affects the lungs and sometimes other parts of the body, such as the brain (meningitis), bones, joints and kidneys.

Corpus luteum (CL) is a yellow hormone-secreting body in the female reproductive system which secretes progesterone. It is a completely normal cyst that forms on the ovary every single month in women of childbearing age. This cyst is actually a group of cells inside ovaries that forms during each menstrual cycle. It appears right after an egg leaves the ovary (ovulation).

Kidney can be taken from a dying person who has the cessation of neurological function only. Tissues such as cornea, heart valves, skin, and bone can be donated in case of natural death but vital organs such as heart, liver, kidneys, intestines, lungs, and pancreas can be donated only in the case of 'brain death'.

The human body is home to millions of microorganisms (microbes). Some microbes make us sick, others are important for our health. The most common types are bacteria, viruses, protozoa and fungi. Viruses are the most adaptable and versatile microorganisms. Viruses can do nothing until they enter a living cell but when enter a living cell they would be able to multiply.