Biology - Online Test
Q1. The giant redwood tree is
Answer : Option D
Explaination / Solution:
One of the gymnosperms, Giant sequoias are the world's largest single tree with an average height of 50–85 m (164–279 ft) and 6–8 m (20–26 ft) in diamete
Q2. Elaioplasts belongs to
Answer : Option D
Explaination / Solution:
The leucoplasts are the colourless plastids of varied shapes and sizes with stored nutrients. Leucoplast includes:
a) Amyloplasts storing carbohydrates.
b) Elaioplastsstoring oils and fats and
c) Aleuroplasts storing proteins.
Q3. The region of t-RNA which consists of three bases complementary to a mRNA codon is
Answer : Option B
Explaination / Solution:
An anticodon is a unit made up of three nucleotides that correspond to the three bases of the codon on the mRNA. Each tRNA contains a distinct anticodon triplet sequence that can base-pair to one or more codons for an amino acid.
Q4. Which is the most effective wavelength of light for photosynthesis?
Answer : Option B
Explaination / Solution:
Certain red and blue wavelengths of light are the most effective in photosynthesis because they have exactly the right amount of energy to energize, or excite, chlorophyll electrons and boost them out of their orbits to a higher energy level.
Q5. The solubility of carbon dioxide is
Answer : Option C
Explaination / Solution:
The solubility of carbon dioxide is 20-25 times higher than that of oxygen, the amount of carbon dioxide that can diffuse through the diffusion membrane per unit difference in partial pressure is much higher compared to that of oxygen.
Q6. Agricultural practices of breeding and raising live stock is called
Answer : Option B
Explaination / Solution:
Animal husbandry is the agricultural practice of breeding, feeding and raring of livestock to obtain animals products like milk, eggs etc.
Q7. UNESCO launched biosphere reserve programme under its MAB in :
Answer : Option A
Explaination / Solution:
Launched in 1971, UNESCO's Man and the Biosphere Programme (MAB) is an intergovernmental scientific programme that aims to establish a scientific basis for the improvement of relationships between people and their environment and to protects the endangered species in natural habitat.
Q8.
Secretion of aldosterone is stimulated by :
i. decrease in sodium ion concentration in the plasma.
ii. decrease in potassium ion concentration in the plasma.
iii. decrease in the volume of blood.
Answer : Option C
Explaination / Solution:
If decreased blood pressure is detected, the adrenal gland is stimulated by these stretch receptors to release aldosterone, which increases sodium reabsorption from the urine, sweat, and the gut. This causes increased osmolarity in the extracellular fluid, which will eventually return blood pressure toward normal.
Q9. Which group of chordates possesses sucking and circular mouth without jaws?
Answer : Option C
Explaination / Solution:
The organism beloging to class Cyclostomes have a sucking and circular mouth without jaws.They are primitive vertebrates. The cyclostomes are marine or fresh-water vertebrates.
Q10. The tissues that allow the penis to fill with blood and become erect is called
Answer : Option D
Explaination / Solution:
Large pockets of erectile tissue in the penis allow it to fill with blood and become erect to increase in size and become turgid during copulation.
