Class 7 Science Chapter 7 MCQ

The urine formed in kidneys goes into the urinary bladder through the tubes called ureters. The urine collected in bladder passed out from the body at regular intervals through the opening at the end of a tube called urethra.

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

Plasma is a pale yellow, sticky liquid. Plasma is 90% water and 3.5% common salt.

Anemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body’s tissues.

White blood cells main chemicals known as antibodies to fight against infection.

In a tall tree, suction force is generated by continuous evaporation of water or transpiration, that pulls up water and minerals absorbed by the roots from the soil to reach the leaves.

Here, all the statements are correct. Hence, your answer will be option [D].

The “left ventricle” pumps oxygenated blood in to main artery for taking it to all the body organs, except lungs. The “right ventricle” pumps deoxygenated blood into pulmonary artery for taking it to lungs.

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

The arteries lie quite deep under our skin and hence they are not seen easily. The veins are less deep than arteries and hence can be seen easily.

Veins have valves in them which allow the blood in them to flow in one direction which is only towards the heart.

The way in which waste product are excreted from the body of an animal depends on the availability of water to it. Aquatic animals live in water, so they excrete cell waste in gaseous form as ammonia which directly dissolves in water.

The top side of left atrium is connected to pulmonary vein which brings oxygenated blood into to heart from the lungs. The left ventricle pumps oxygenated blood in to main artery for taking it to all the body organs, except lungs. The top side of right atrium is connected to main vein called vena-cava, which brings deoxygenated blood into heart from all the body organs, except lungs. The right ventricle pumps deoxygenated blood into pulmonary artery for taking it to lungs. In the rhythmic contraction of heart where valves prevents the backflow of blood inside the heart during contraction.

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

The arteries have thick and elastic walls because blood flows through them at high pressure. The thick and elastic walls of arteries can withstand the high pressure of blood flowing through them. Veins have valves in them which allow the blood in them to flow in one direction only that is towards the heart.

Each kidney contains thousands of tiny filters called nephrons.

Urine contains 88 % of excreted nitrogen (N), 67 % of excreted phosphorous (P) and 73% of excreted potassium (K),“the remainder is in the faeces”. An adult excretes on average 500 liters (0.8-1.5 L per day in 4-5 times) of urine and 50 liters of faeces per year. Children urinates about half of the adult’s amount.

Sweat glands are absent in lips. These glands produce a liquid waste called sweat that contains water, salts and little urea. These are found over most of the body part.

Veins normally carry deoxygenated blood or rich in carbon dioxide from the body organs. One vein that is “Pulmonary vein” carries oxygenated blood or rich in oxygen from the lungs to the heart.

The excretory system of human beings consists of the following organs as two kidneys, two ureters, a bladder and a urethra. Every person has two kidneys. The function of kidney is to filter the blood to remove urea. Each kidney contains thousands of tiny filters called “Nephron”.

Capillaries are the extremely thin blood vessels where exchange of substances and absorption of nutrients takes place. Their thin walls facilitated the exchange. They connect arteries (carry oxygenated blood from the heart) to veins (carry deoxygenated blood from all the parts of the body to the heart).