CSS MPT Everyday Science Practice Set — 1000 Advanced Booklet (Q201–250) — Solved One-Liners with Answers Solved MCQs

Correct Answer: Skin

The skin is the largest organ of the human body, covering about 2 square metres in an adult.

Correct Answer: Liver

The liver is the largest internal organ of the human body, weighing about 1.5 kg in an adult.

Correct Answer: Stapes (ear bone)

The stapes, one of the three tiny ossicles of the middle ear, is the smallest bone in the human body, about 3 mm long.

Correct Answer: Femur (thigh bone)

The femur, the thigh bone, is the longest and strongest bone in the human body.

Correct Answer: 206

The adult human skeleton normally has 206 bones.

Correct Answer: 270

A newborn baby has about 270 bones; many are separate pieces of cartilage that fuse as the child grows, leaving 206 in the adult.

Correct Answer: 24 (12 pairs)

The human rib cage normally has 24 ribs, 12 pairs attached to the thoracic vertebrae.

Correct Answer: 33

The human spine has 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused) and 4 coccygeal (fused).

Correct Answer: 46 (23 pairs)

A normal human cell has 46 chromosomes in 23 pairs: 22 pairs of autosomes plus one pair of sex chromosomes.

Correct Answer: 22

The human skull has 22 bones: 8 cranial bones and 14 facial bones (excluding the 6 ear ossicles).

Correct Answer: Plasma

Plasma is the straw-coloured fluid part of blood, about 55% of blood volume, carrying cells, nutrients and hormones.

Correct Answer: Hemoglobin

Hemoglobin, the iron-containing pigment in red blood cells, binds oxygen and gives blood its red colour.

Correct Answer: Leukocytes

White blood cells are called leukocytes; they defend the body against infection (erythrocytes are red cells, thrombocytes are platelets).

Correct Answer: Blood clotting

Platelets (thrombocytes) are cell fragments that clump and trigger clotting to stop bleeding.

Correct Answer: 7.35–7.45

Normal human blood pH is slightly alkaline, 7.35–7.45; values outside this range are clinically abnormal.

Correct Answer: 5–6 liters

An average adult has about 5–6 litres of blood, roughly 7–8% of body weight.

Correct Answer: O Negative

O Negative blood lacks A, B and Rh antigens, so it can be given to recipients of any blood group in emergencies.

Correct Answer: AB Positive

AB Positive recipients have no anti-A or anti-B antibodies and are Rh positive, so they can receive blood of any group.

Correct Answer: 37°C (98.6°F)

Normal human body temperature is about 37°C (98.6°F), with small variation through the day.

Correct Answer: Aorta

The aorta, which carries oxygenated blood from the left ventricle to the body, is the largest artery.

Correct Answer: Inferior Vena Cava

The inferior vena cava, which returns blood from the lower body to the right atrium, is the largest vein.

Correct Answer: 4

The human heart has four chambers: two atria and two ventricles.

Correct Answer: 72 beats per minute

The average resting heart rate in adults is about 72 beats per minute (the normal resting range is roughly 60–100).

Correct Answer: SA Node

The sinoatrial (SA) node in the right atrium generates the electrical impulses that set the heart's rhythm, so it is called the natural pacemaker.

Correct Answer: Vitamin K

Vitamin K is needed to make clotting factors (including prothrombin) in the liver; without it, blood does not clot properly.

Correct Answer: Night Blindness

Vitamin A deficiency first impairs vision in dim light (night blindness) and can progress to xerophthalmia.

Correct Answer: Beriberi

Vitamin B1 (thiamine) deficiency causes beriberi, affecting the nerves, heart and muscles.

Correct Answer: Pernicious Anemia

Vitamin B12 deficiency impairs red blood cell formation and causes pernicious (megaloblastic) anemia.

Correct Answer: Scurvy

Vitamin C deficiency causes scurvy: bleeding gums, weak connective tissue and poor wound healing.

Correct Answer: Rickets

Vitamin D deficiency in children causes rickets, soft and weakened bones; in adults the equivalent is osteomalacia.

Correct Answer: Infertility

Vitamin E deficiency is classically linked in textbook one-liners to reproductive failure (sterility).

Correct Answer: Hemorrhage

Vitamin K deficiency impairs clotting, so bleeding (hemorrhage) does not stop normally.

Correct Answer: Vitamin A

Vitamin A (retinol) is essential for vision: it forms rhodopsin, the light-sensitive pigment of the retina.

Correct Answer: Vitamin D

Vitamin D promotes calcium absorption from the gut, which is essential for strong bones.

Correct Answer: Vitamin C

Vitamin C is chemically ascorbic acid, a water-soluble antioxidant.

Correct Answer: Vitamin B2

Riboflavin is vitamin B2, needed for energy metabolism and healthy skin and eyes.

Correct Answer: Vitamin B3

Niacin is vitamin B3, needed for energy metabolism; its deficiency causes pellagra.

Correct Answer: Vitamin B9

Folic acid (folate) is vitamin B9, essential for DNA synthesis and for preventing neural tube defects in pregnancy.

Correct Answer: Vitamin B12

Cobalamin is vitamin B12, needed for red blood cell formation and nerve function.

Correct Answer: Amla (Gooseberry)

Amla (Indian gooseberry) is exceptionally rich in vitamin C, containing far more per 100 g than oranges or lemons.

Correct Answer: Sunlight exposure

Sunlight is the main source of vitamin D: ultraviolet light on the skin synthesises vitamin D, which food alone rarely supplies in full.

Correct Answer: Carrots

Carrots are the conventional one-liner answer for the richest source of vitamin A, as a rich source of beta-carotene, which the body converts to vitamin A.

Correct Answer: Vegetable oils

Vegetable oils (especially wheat germ, sunflower and safflower oils) are rich sources of vitamin E.

Correct Answer: Green leafy vegetables

Green leafy vegetables such as spinach, kale and cabbage are rich sources of vitamin K.

Correct Answer: Liver

The liver is the largest gland in the human body, weighing about 1.5 kg; it secretes bile and performs hundreds of metabolic functions.

Correct Answer: Pineal gland

The pineal gland, about 5–8 mm long in the brain, is the smallest gland in the human body, smaller than the pea-sized pituitary gland.

Correct Answer: Pituitary gland

The pituitary gland is called the master gland because its hormones control several other endocrine glands.

Correct Answer: Pancreas

Insulin is secreted by the beta cells of the islets of Langerhans in the pancreas.

Correct Answer: Adrenaline

Adrenaline (epinephrine), released by the adrenal medulla, prepares the body for fight or flight: faster heartbeat, raised blood pressure and blood sugar.

Correct Answer: Insulin

Insulin lowers blood sugar by helping cells take up glucose; glucagon acts in the opposite direction, raising it.