All Free Biology MCQs with Answers

• A. Sarcoplasm
• B. Sarcolemma
• C. Sarcomere
• D. Myofibrils

Explanation: The sarcolemma is the specialized cell membrane of muscle cells, also known as muscle fibers.

• A. Voluntary
• B. Branched
• C. Uninucleate
• D. Striated appearance

Explanation: Muscles that are uni-nucleate, meaning they contain a single nucleus per cell, primarily include cardiac muscle and smooth muscle.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Explanation:When the neuron is under action potential, the charges on the membrane are reversed.

• A. Serotonin
• B. Acetylcholine
• C. Dopamine
• D. Adrenaline

Explanation: Explanation:The neurotransmitter that lies outside the central nervous system is Acetylcholine, it is only present in the PNS.

• A. Is more positive outside than inside
• B. Is more negative outside than inside
• C. Has no charge on either side
• D. Has an equal charge on either side

Explanation: Option [A] A typical neuron is more positive outside than inside due to the presence of Na+ K+ pump which countertransports 3Na+ outside…

• A. Resting membrane potential
• B. Saltatory nerve impulse
• C. Threshold stimulus
• D. Initial nerve impulse

Explanation: Saltatory conduction describes how an electrical impulse skips from node to node down the full length of an axon, speeding the arrival of…

• A. Sensory nerve fibres
• B. Myelinated nerve fibres
• C. Motor nerve fibres
• D. Mixed nerve fibres

Explanation: White matter is found in the deeper tissues of the brain (subcortical).

• A. Auxins.
• B. Gibberellins.
• C. Abscisic acid.
• D. Ethane.

Explanation: Gibberellins promote leaf and fruit growths.

• A. Nastic.
• B. Growth.
• C. Turgor.
• D. Tactic.

Explanation: Nastic movements are a type of paratonic movement.

• A. Synchronizes.
• B. Promotes.
• C. Inhibits.
• D. Does not affect.

Explanation: It has been found that red light Inhibits flowering the short day plants but promotes flowering in long day plants.

• A. Enhancement of cell differentiation
• B. Maturation of the cells
• C. Elongation of cells
• D. Enhancement of cell division

Explanation: Explanation:Red light favours elongation of cells and blue light enhances cell division but retards cell enlargement.When red light can…

• A. Carbon dioxide.
• B. Water.
• C. Hormones.
• D. Nutrition.

Explanation: Environmental factors that affect plant growth include light, temperature, water, and humidity.

• A. Infestation.
• B. Exudation.
• C. Bleeding.
• D. Imbibition.

Explanation: Closely associated with root pressure is a phenomenon called guttation or exudation.

• A. Yellow.
• B. Violet-blue.
• C. Green.
• D. Indigo.

Explanation: All plants have chlorophyll a which absorbs most strongly at ~450 nm, or a bright blue color.

• A. Both B, D.
• B. Hydrophytes
• C. None of B, D.
• D. Xerophytes.

Explanation: Xerophytes are plants adapted to arid or dry environments. They have adaptations to conserve water and tolerate drought conditions.

• A. NO2
• B. Calcium
• C. Gypsum
• D. Nitrogen

Explanation: d) Nitrogen: This is the correct option. Nitrogen is necessary for the development of leaves and is a critical component of chlorophyll…

• A. Golgi Bodies
• B. Mitochondria
• C. Glyoxysome
• D. Peroxisome

Explanation: Explanation:In the Peroxisomes, glycolate is oxidized with O2 uptake to glyoxylate by glycolate oxidase, and the glyoxylate is converted…

• A. 6 - 200 g per acre
• B. 4-40 g per acre
• C. 6 - 200 kg per acre
• D. 4 - 40 kg per acre

Explanation: Explanation:Micronutrients are required in quantity ranging from 6-200 grams per acre.

• A. Mango
• B. Tobacco
• C. Wheat
• D. Rice

Explanation: Explanation:Potassium fertilizers are especially useful for tobacco, coffee, potato, and corn.This option is not correct.

• A. Leaves
• B. Fruits
• C. Root hairs
• D. Branches

Explanation: A is incorrect as the growth of the leaves is dependent on nitrogen.B is incorrect as the development of fruit depends on phosphorous.C is…