CBSE 12TH BIOLOGY - Online Test
Q1. Assertion: Coacervates are believed to be the precursors of life.
Reason: Coacervates were self-duplicating aggregates of proteins surrounded by lipid molecules.
Reason: Coacervates were self-duplicating aggregates of proteins surrounded by lipid molecules.
Answer : Option C
Explaination / Solution:
Coacervates are believed to be the precursors of life. These molecules consists protein along with lipids. They are aggregates of proteins surrounded by lipid but self-duplicating ability were not present in them.
Q2. Which one of the following pairs is wrongly matched
Answer : Option D
Explaination / Solution:
Water hyacinth develops offset for vegetative propagation. Its forms large number of branches in very short interval of time to cover the whole water bodies and depriving other aquatic organisms from oxygen dissolved in water.
Q3. Successive transitional communities will show
Answer : Option D
Explaination / Solution:
During ecological succession, transitional communities or seral communities will show increase in the number of species due to addition of nutrient medium at successive stages of succession.
Q4. An MNC exploiting biological resources (turmeric) of other nation without proper authorization will be called as
Answer : Option C
Explaination / Solution:
Exploiting biological resources of other nation without proper authorization from the country or people concerned without compensatory payment is called biopiracy.
Q5. World population day is celebrated on
Answer : Option B
Explaination / Solution:
World population day is celebrated on 11th July every year world over to create awareness about the ill effect of unchecked population explosion.
Q6. The major approach towards the crop improvement programme is
Answer : Option C
Explaination / Solution:
Crop improvement programme is carried out to obtain crops with desired traits that may be more yields, resistance to disease, higher nutrient value etc. Two plants having desired traits are hybridized to obtain combination of desired traits.
Q7. The birth rate if 7 new plants are added to previous year plant population of 23 Salvinia plants will be
Answer : Option B
Explaination / Solution:
The birth rate of a population =
Here birth rate=
Hence, birth rate of Salvinia plants is equal to 0.3.
Q8. Which plant is responsible for doing hallucination?
Answer : Option C
Explaination / Solution:
Hallucination is a condition in which a person feels pleasure in spite of stress and other mental problems. In this condition, central nervous systems get influenced and reduce the thinking capacity. Datura, Atropa baladona and erythroxylum coca, all cause hallucination.
Q9. Which one of the following pairs is correctly matched with regard to the codon and the amino acid coded by it?
Answer : Option D
Explaination / Solution:
Lysine, encoded by the codons AAA and AAG, is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group, an α-carboxylic acid group, and a side chain lysyl, classifying it as a charged, aliphatic amino acid.
UUA, AUG and CCC do not code for Valine, cysteine and alanine respectively.
Q10. The maintenance of hives of honeybees for the production of honey is
Answer : Option C
Explaination / Solution:
Maintenance of bee hives of honey bees for production of honey is called apiculture. Apiculture can be practiced in any area having pasture of herbs and flowering plants.
