Biology Quiz 7

There are 23 chromosomes in a human ovum and 23 chromosomes in human sperm. Healthy humans have 23 pairs of chromosomes in which 22 pairs are autosomes and 2 are sex chromosomes. The ovum (female gamete) is formed by the meiosis due to which they have only the half number of chromosomes, which means 22 autosomes (11 pairs) and 1 sex chromosome.

Bullets contain lead, and once in the body, it can cause lead poisoning. Most pistol bullets are made of a lead-antimony alloy encased in a soft brass or copper-plated soft steel jacket. In rifle and machine-gun bullets, a soft core of lead is encased in a harder jacket of steel or cupronickel.

The medical term used for sleeplessness is Insomnia. It is a common sleep disorder that can make it hard to fall asleep, hard to stay asleep or cause to wake up too early and not be able to get back to sleep.

Physical exercise is one of the most effective tools for strengthening the heart muscle, keeping weight under control and warding off the artery damage from high cholesterol, high blood sugar and high blood pressure that can lead to heart attack or stroke.

Sunlight is not required for seed germination. Light isn't strictly necessary for germination in most plant species. All seeds need water, oxygen and suitable temperature to germinate.

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.

Trypanosomiasis, also known as sleeping sickness, is caused by microscopic parasites of the species Trypanosoma brucei.

Hypothalamus is the gland that holds the body's thermostat. It is involved in different daily activities like eating or drinking, in the control of the body's temperature and energy maintenance, and in the process of memorizing and in stress control. It acts as the body's smart control coordinating centre.

Cytology is the study of cells as fundamental units of living things. A cytology test is used to look closely at cells and body fluids.

Vitamin E is particularly important for the normal activity of sex glands as it improves blood flow and oxygen to sexual organs. It is an antioxidant that helps to maintain healthy skin, eyes and hormonal balance. It also enhances immune function and prevents clots from forming in heart arteries.