CBSE 12TH BIOLOGY - Online Test
Q1. Biotic components of a habitat includes
Answer : Option B
Explaination / Solution:
Biotic components include all living organisms present in an ecosystem. Competitors and predators are biotic components of habitat.
Q2. The disease causing microorganisms are called
Answer : Option A
Explaination / Solution:
A number of bacteria, fungi, virus etc. cause disease in human beings. These disease causing microbes are called pathogens.
Q3. Genetic information is carried out by long chain molecule made up of
Answer : Option C
Explaination / Solution:
Genetic information is carried out by DNA and RNA. Both DNA and RNA are called genetic material, made up of long chain of nucleotide having- nitrogenous base, sugar and phosphate ions.
Q4. Flow of energy in our ecosystem takes place
Answer : Option A
Explaination / Solution:
In ecosystem, flow of energy takes place in only one direction. The flow of energy takes place from producers to final consumers. Energy present in one trophic levels nevers return back to producer.
Q5. Best method to increase crop yield is
Answer : Option D
Explaination / Solution:
Crop production can be increased by adopting a number of methods like using seeds of improved varieties, using modern method of agriculture, using fertilizers and pesticides. An improved seed variety is most important for better yield.
Q6. Speciation maintains biodiversity
Answer : Option C
Explaination / Solution:
Speciation, the formation of new and distinct species in the course of evolution. Speciation involves the splitting of a single evolutionary lineage into two or more genetically independent lineages.
Speciation maintains biodiversity both at species level and community level. New species develop from older species due to variation having more adaptive in changed habitat.
Add image here
Q7. Flower is the site of
Answer : Option A
Explaination / Solution:
Sexual reproduction in flowering plants centres around the flower. Within a flower, there are usually structures that produce both male gametes and female gametes.
Q8. Which of the following is a primary sex organ of female?
Answer : Option C
Explaination / Solution:
Ovary is the primary sex organ of female reproductive system in human beings. Egg is released from one of the ovary each month. It also release hormone.
Q9. The innate tendency of offspring to resemble their parents is called
Answer : Option D
Explaination / Solution:
The innate tendency of offspring to resemble their parents is called heredity. The offspring resembles to parent due to same genetic combination inherited from parents.
Q10. Micro-organisms that grow in milk and convert it to curd is commonly called
Answer : Option A
Explaination / Solution:
The micro-organisms that grow in milk and convert it to curd is commonly called lactic acid bacteria. Micro-organism such as Lactobacillus and others commonly called as lactic acid bacteria (LAB).
