Multiple-Choice Questions

Rita suffers from constant headaches and high blood pressure. Her residence is close to an airport. What could be the most likely cause of her condition?

1. Noise pollution
2. Air pollution
3. Nuclear pollution
4. Water pollution

Answer

Noise pollution

Reason — Living close to an airport exposes Rita to constant noise from airplanes taking off and landing, which can lead to noise pollution. Prolonged exposure to high levels of noise can cause stress, increase blood pressure, and result in headaches.

An exo-endocrine gland in the human body is:

1. Pituitary gland
2. Pancreas
3. Salivary gland
4. Adrenal gland

Answer

Pancreas

Reason — The pancreas is an exo-endocrine gland because it has both exocrine and endocrine functions. It secretes digestive enzymes into the small intestine via ducts (exocrine activity) and produces hormones like insulin and glucagon, which are released directly into the bloodstream to regulate blood sugar levels (endocrine activity).

Assertion: If both kidneys fail, urea from the blood is removed by dialysis.

Reason: Accumulation of urea in the human body is toxic.

1. A is True, and R is false.
2. A is False, and R is true.
3. Both A and R are true.
4. Both A and R are false.

Answer

Both A and R are true.

Reason — Dialysis is a medical process used to remove waste products like urea from the blood when the kidneys are not functioning properly. Urea is a waste product produced in the body and its accumulation can lead to toxicity if not removed.

Rajesh was told to buy a blue cloth by his craft teacher. He couldn't differentiate blue colour from green and hence brought a green cloth to class. Which medical reason could have resulted in this?

1. Myopia
2. Cataract
3. Colour blindness
4. Hyperopia

Answer

Colour blindness

Reason — Colour blindness is genetic medical condition in which the patient is not able to differentiate between the colours.

Mary sprinkled 5 kg of common salt on the grass growing on her lawn. After a couple of days, she observed that the grass had wilted and died. This was due to which of the following conditions?

1. Endosmosis
2. Turgidity
3. Deplasmolysis
4. Plasmolysis

Answer

Plasmolysis

Reason — The salt makes the soil solution hypertonic. When cells come in contact with the soil solution, the cell sap comes out by exosmosis resulting in shrinkage of cell known as plasmolysis. Plasmolysis cause wilting of plant.

In cholera, patients suffer from vomiting and watery bowels. They may die due to the:

1. poisoning by the accumulation of high quantities of urea in the body.
2. ability of the intestines to absorb water into the blood.
3. excretion of almost all the water by the kidneys.
4. the failure of the kidneys.

Answer

poisoning by the accumulation of high quantities of urea in the body.

Reason — Due to vomiting and watery bowels, the intestine are unable to absorb water into the blood. Therefore, to maintain the osmotic pressure of blood kidneys reabsorb almost all the water along with urea. This further causes poisoning by the accumulation of high quantities of urea in the body.

The given figures A and B show ............... and ............... stages of cell division.

1. prophase, metaphase
2. telophase, anaphase
3. metaphase, anaphase
4. anaphase, telophase

A

B

Answer

metaphase, anaphase

Reason — During metaphase, the chromosomes align themselves along the equatorial plane of the cell, called the metaphase plate. In anaphase, the sister chromatids of each chromosome are pulled apart by the spindle fibers towards the opposite poles of the cell. The centromeres split, and the chromatids (now individual chromosomes) move away from the center.

A person is suffering from kidney failure. He is put on a dialysis machine by the doctors. The osmotic pressure of dialysis fluid should be:

1. equal to that of blood.
2. more than that of blood.
3. less than that of blood.
4. equal to zero.

Answer

equal to that of blood.

Reason — In dialysis, the osmotic pressure of the dialysis fluid should be equal to that of blood to prevent excessive movement of water either into or out of the blood. This ensures that waste products like urea and excess salts are removed without causing an imbalance in fluid levels or electrolytes in the body.

A squirrel is in a scary situation. The secreted adrenaline prepares the body to meet the situation. Which of the following is NOT TRUE for this situation?

1. Adrenaline prepares the body to fight danger.
2. Extra energy and strength are provided to the body.
3. At the time of the stress, fewer hormones are released into the blood.
4. Adrenaline prepares the body to run away from danger.

Answer

At the time of the stress, fewer hormones are released into the blood.

Reason — In a stressful situation, more hormones, including adrenaline and other stress-related hormones, are released into the bloodstream to help the body cope with the stress.

Assertion (A): The main pulmonary artery pumps oxygenated blood from the right ventricle into the lungs.

Reason (R): Inside the lungs, the artery divides and divides several times to form capillaries around the air sacs.

1. A is True, and R is false.
2. A is False, and R is true.
3. Both A and R are true.
4. Both A and R are false.

Answer

A is False, and R is true

Reason — The pulmonary artery does not pump oxygenated blood. In fact, it pumps deoxygenated blood from the right ventricle to the lungs for oxygenation. After oxygenation, the oxygenated blood returns to the heart through the pulmonary veins.

Given below are some common reflexes in humans.

i. Quick closing of the eyelids when a strong beam of light is flashed across.

ii. Apply brakes to your vehicle if anything suddenly comes in front.

iii. Playing a musical instrument.

iv. Coughing reflex, when the food is swallowed, enters the windpipe.

The conditioned reflexes are:

1. i and ii
2. ii and iii
3. iii and iv
4. i and iv

Answer

ii and iii

Reason — Quick closing of the eyelids when a strong beam of light is flashed across and coughing reflex, when the food is swallowed, enters the windpipe are natural or inborn reflexes. Playing a musical instrument and applying brakes are learnt by practice and thus they are conditioned reflexes.

Electrons released on splitting of water molecules in photosynthesis are used in producing:

1. NADP
2. NADPH
3. ATP
4. O₂

Answer

ATP

Reason — During light dependent phase of photosynthesis, the electrons released on splitting of water molecules are used in converting ADP into ATP by adding one phosphate group.

The four major steps in seeing an object are:

i. interpretation by the brain.

ii. focussing of image.

iii. entry of light rays.

iv. transmission of nerve impulses from the retina & brain.

The correct sequence will be:

1. i, ii, iii, iv
2. ii, iii, iv, i
3. iii, ii, iv, i
4. iv, i, ii, iii

Answer

iii, ii, iv, i

Reason — The four major steps in seeing an object arranged in order are:

entry of light rays → focussing of image → transmission of nerve impulses from the retina & brain. → interpretation by the brain

Based on the given figure, identify the structural as well as the functional unit of kidney:

1. A
2. B
3. C
4. D

Answer

C

Reason — The part C in the picture is a nephron. It is the structural and functional unit of kidney.

Assertion: Seminiferous tubules produce sperms.

Reason: Seminiferous tubules secrete Oxytocin, which aids in the production of sperm.

1. A is True, and R is false.
2. A is False, and R is true.
3. Both A and R are true.
4. Both A and R are false.

Answer

A is True, and R is false.

Reason — The seminiferous tubules, located in the testes, are the site where spermatogenesis (the production of sperm cells) occurs. Oxytocin is not involved in sperm production. It is a hormone primarily known for its role in childbirth and lactation in females.

Assertion: The nerve impulse travels from the axon of a neuron to the axon of another neuron.

Reason: The end portion of the axon has swollen ends, which store neurotransmitters.

1. A is True, and R is false.
2. A is False, and R is true.
3. Both A and R are true.
4. Both A and R are false.

Answer

A is False, and R is true

Reason — The nerve impulse travels from the axon of one neuron to the dendrite or cell body of another neuron across a small gap called as synapse.

Thomas played cricket on a hot summer afternoon. His urine output was much less, though he drank plenty of water. What could be the possible cause?

P - Kidneys reabsorb a lot of water
Q - Sweat glands are active
R - Kidneys absorb less water
S - Sweat glands are inactive

1. R and Q
2. P and Q
3. P and S
4. R and S

Answer

P and Q

Reason — While playing, the player loses most of water through the sweat glands. Therefore, the kidneys reabsorb most of the water back in the blood to maintain the composition and osmotic pressure of blood. This results in less volume of urine.

Acid rain is caused due to polluted gases like CO₂, SO₂, and oxides of nitrogen. The pollution which does not take place immediately after acid rain is:

1. Air pollution
2. Water pollution
3. Soil Pollution
4. Noise Pollution

Answer

Air pollution

Reason — After rainfall the pollutants present in the air are washed away with rain droplets. This clears the air of any pollution.

Surya's father was diagnosed with Diabetes mellitus. The doctor advised him to avoid certain foods. Which are the foods he should avoid eating?

P - Sweets
Q - Leafy vegetables
R - Bananas
S - Pulses

1. P and R
2. Q and S
3. R and S
4. P and Q

Answer

P and R

Reason — For patients of Diabetes mellitus, it is important to control blood sugar levels by avoiding foods that can cause spikes in blood glucose. Sweets and bananas have high sugar content and therefore, they can spike the blood glucose level.

During light adaptation:

1. Rods and cones become active.
2. Rods and cones become inactive.
3. Rods become active and cones inactive.
4. Cones become active and rods inactive.

Answer

Cones become active and rods inactive.

Reason — The rods, which are more sensitive to low light and are responsible for vision in dim conditions, become inactive in bright light. In bright light, the cones, which are responsible for colour vision and sharp vision in bright conditions, become active.

A cell of a leaf of an aquatic plant is kept in a 5% salt solution for some time. The phenomenon which will take place is/are:

1. turgidity
2. plasmolysis
3. turgidity and flaccidity
4. plasmolysis and flaccidity

Answer

plasmolysis and flaccidity

Reason — When a cell of an aquatic plant is placed in a 5% salt solution (which is hypertonic to the cell), water will move out of the cell due to osmosis. This causes the cell membrane to shrink away from the cell wall, leading to plasmolysis. As a result, the cell will lose its firmness, becoming flaccid. Therefore, both plasmolysis and flaccidity will occur.