CBSE 12TH BIOLOGY - Online Test
Q1. “In Competition, the superior competitor eliminates the inferior one”, this statement is called:
Answer : Option B
Explaination / Solution:
In competition, superior competitor eliminates the inferior one. This statement is called Gause’s competitive exclusion principle. Two closely related competing for same resources cannot co-exist indefinitely and inferior will be eliminated.
Q2. AIDS day is
Answer : Option B
Explaination / Solution:
World AIDS Day, designated on 1 December every year since 1988, is dedicated to raising awareness of the AIDS pandemic caused by the spread of HIV infection, and mourning those who have died of the disease.
Q3. Codon is made up of
Answer : Option A
Explaination / Solution:
A codon is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis. A codon is a triplet.
Q4. Which of the following fungi is used as food
Answer : Option A
Explaination / Solution:
Mushrooms are eaten by many people and large scale mushroom culture is a growing industry. It is a rich source of protein and other micronutrients.
Q5. Read the following statements :
a) India is considered as one of the 12 mega diversitycenters of the world.
b) India contributes to a high percentage of global species diversity.
a) India is considered as one of the 12 mega diversitycenters of the world.
b) India contributes to a high percentage of global species diversity.
Answer : Option D
Explaination / Solution:
The megadiverse countries are a group of countries that harbor the majority of Earth's species and high numbers of endemic species. Conservation International identified 17 megadiverse countries in 1998.
India is one of the twelvemega diversity countries of the world with bio-diversity hot spots such as Eastern Himalayaand the Western Ghats,
With only 2.4% of world's land area, India accounts for 7-8% of recorded species of the world. In terms of species richness, India ranks seventh in mammals, ninth in birds and fifth in reptiles.
Q6. Endometrium is the lining of
Answer : Option B
Explaination / Solution:
The inner lining of uterus is called endometrium. It gets ruptured at the beginning of menstrual cycle and comes out through vagina along with blood vessels. It is formed in expectation of pregnancy every month.
Q7. In humans, height shows a lot of variation. It is an example of
Answer : Option D
Explaination / Solution:
Height of human being is not controlled by single pair of gene. A number of genes participate to form growth hormone that actually triggers the height of individual.
Q8. Use of biocontrol measures will greatly reduce our dependence on
Answer : Option B
Explaination / Solution:
The use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides. Insects and pests are not killed in this method but kept undercontrol.
Q9. Mass destruction of aquatic life will be caused by:
Answer : Option D
Explaination / Solution:
Mass destruction of aquatic life will be caused by broad spectrum pesticides. Broad spectrum pesticides are effective against large number of pests whether useful or harmful. These pesticides reaches to water bodies along with rain water.
Q10. Overhangs produced by restriction enzymes are called as
Answer : Option D
Explaination / Solution:
Longer overhangs are called cohesive ends or sticky ends. They are most often created by restriction endonucleases when they cut DNA.
