All Free Biology MCQs with Answers

• A. Molecules of dissolved substance move from left to right
• B. Molecules of dissolved substance move from right to left
• C. Overall, water molecules move from left to right.
• D. Overall, water molecules move from right to left

Explanation: Water molecules move from the left to right as water potential is higher on the left side than the right side.

• A. Right Atrium
• B. Left Atrium
• C. Right Ventricle
• D. Left Ventricle
• E. Aorta

Explanation: The right atrium is the part of the heart that receives deoxygenated blood from the whole body via the superior and inferior vena cava.

• A. A
• B. B
• C. C
• D. Both A and B
• E. Both C and D

Explanation: Option B is the isotonic solution, and option C is the hypotonic solution as it causes the cells to fill with water due to the movement of…

• A. Liver
• B. Intestine
• C. Liver and Intestine
• D. Adipose tissue

Explanation: a) Liver: High-Density Lipoprotein (HDL) is synthesized in the liver. HDL is a type of lipoprotein that plays a crucial role in the…

• A. Both the atria are towards the left side
• B. Both the ventricles are towards the left side
• C. Entire heart is on the left side
• D. The aorta is on the left side

Explanation: Option B: This option is the correct answer. It states that the beating of the heart is heard on the left side because both the ventricles…

• A. Ascent of sap
• B. Plasmolysis
• C. Imbibition
• D. Guttation

Explanation: A hydathode is a type of pore, commonly found in angiosperms, that secretes water through pores in the epidermis of leaf margin through…

• A. Over extension
• B. Abrasion
• C. Physical trauma
• D. Contraction

Explanation: Pericardium prevents the heart from over extension; Pericardial fluid prevents the heart from abrasion and ribcage prevents it from…

• A. Cellulose
• B. Lignin
• C. Pectin
• D. Glucose

Explanation: Answer is "Glucose"Explanation: Glucose is soluble in water because it is a monosaccharide in nature.

• A. Secondary cell wall
• B. Middle lamella
• C. Cell membrane
• D. Primary cell wall

Explanation: The primary cell wall of the plant is composed of cellulose, pectic compounds mostly polysaccharides, and hemicellulose. It lacks lignin.

• A. MC complex
• B. lmmunogen
• C. Mucus
• D. Antibodies

Explanation: An antigen is a foreign substance that can stimulate the production of antibodies by the immune system.

• A. Plasmodcsmala
• B. Cortex
• C. Endodennis
• D. Pith

Explanation: In roots, the apoplast pathway of water is disrupted when water reaches the endodermis.

• A. Erythrocytes
• B. Leukocytes
• C. Neutrophils
• D. Thrombocytes

Explanation: Thrombocytes are called blood platelets.They are minute disc­shaped cell fragments in mammalian blood.

• A. Capillaries
• B. Arteries
• C. Veins
• D. Lymph vessels

Explanation: Yes, the fastest distribution of an injectable material or medicine is achieved by injecting it into the veins.

• A. Atrioventricular bundle
• B. Purkinje system
• C. Sinoatrial node
• D. Atrioventricular node

Explanation: SA (sinoatrial) node is a specialized bundle of neurons located in the upper part of the right atrium of the heart.

• A. Diffusion
• B. Active transport
• C. Osmosis
• D. Facilitated diffusion

Explanation: Answer is "Osmosis"The movement of water molecules from a region of higher water potential to a region of lower water potential through…

• A. Root hairs
• B. Root cells
• C. Underground stem
• D. Leaves

Explanation: Root hairs are specialized structures that extend from the surface of root cells and greatly increase the surface area for water and…

• A. Cisternae
• B. Tonoplast
• C. Cristae
• D. Protoplast

Explanation: The membrane that surrounds the vacuole in plant cells is called the tonoplast.

• A. echinodermata
• B. mollusca
• C. nematoda
• D. arthropoda

Explanation: Arthropods commonly show tagmatization into head, thorax, and abdomen, with jointed appendages and an external exoskeleton.

• A. gastropods
• B. bivalves
• C. arthropods
• D. platyhelminthes

Explanation: Snails are gastropods, a molluscan group characterized by a muscular foot and, in most members, a single coiled shell.

• A. Older sediment layers have equal amount of these reaioactive isotopes as that of the young ones
• B. Older sediment layers have less amount of these reaioactive isotopes as that of the young ones.
• C. Older sediment layers have greater amount of these radioactive isotopes as that of the young ones.
• D. Older sediment layers did not have these radioactive isotopes

Explanation: Radioactive parent isotopes decay into daughter products over time, so an older rock generally contains less of the original radioactive…