CBSE 12TH BIOLOGY - Online Test
Q1. The value of ecosystem services of biodiversity is
Answer : Option D
Explaination / Solution:
The value of ecosystem services of biodiversity is difficult to determine as it includes services like cultural and spiritual value along with life saving services for all organisms.
Q2. Human protein α-1-antitrypsin is used to treat
Answer : Option D
Explaination / Solution:
Transgenic organisms produce useful biological products. Augmentation therapy is the use of alpha-1 antitrypsin protein (AAT) from the blood plasma of healthy human donors to augment (increase) the alpha-1 levels circulating in the blood and lungs of Alphas diagnosed with emphysema.
Human protein α-1-antitrypsin is used to treat emphysema is also obtained from transgenic animal.
Q3. The period between entry of pathogen into the body and appearance of first symptom is called
Answer : Option A
Explaination / Solution:
The period between entry of pathogen into the body and appearance of first symptom is called incubation period. It varies from a few days up to 7 years as in case of AIDS.
Q4. If an endosperm cell of angiosperm contain 24 chromosome, the number of chromosome in each cell of root is
Answer : Option C
Explaination / Solution:
Endosperm cells are triploid as they are formed by triple fission of two polar nuclei and one male gamete. So, haploid cell will contain 8 chromosomes only. Root cells are diploid. Hence root cell will contain 16 chromosomes.
Q5. An example of predation is
Answer : Option C
Explaination / Solution:
Biological control method adopted in agricultural pest control are based on the ability of predator to regulate prey population.
Q6. AIDS can be transmitted by
Answer : Option C
Explaination / Solution:
AIDS can be transmitted from infected person to healthy person through blood transfusion. The most common way of transmission of AIDS is during sexual intercourse with multiple partners without protection.
Q7. Protein synthesis occurs over
Answer : Option B
Explaination / Solution:
Protein synthesis occurs over ribosomes which are also called protein factories of cell. Each ribosomes have two parts 40S and 60S in eukaryotes and 30S and 50S in prokaryotes.
Q8. Norin-10 gene is famous for
Answer : Option B
Explaination / Solution:
Norin-10 gene is used to obtain dwarf varieties of crops like rice and wheat. This gene is introduced in crop plants by using technique of genetic engineering.
Q9. A network of tubules present inside the testis to store the sperm is called
Answer : Option C
Explaination / Solution:
Seminiferous tubules of testis open into the vasa efferentia through rete testis. Rete testis is network of tubules inside the testis to store the sperm temporarily.
Q10. Chromosomal theory of inheritance was experimentally verified by T.H.Morgan and his colleagues working with tiny flies
Answer : Option D
Explaination / Solution:
T.H.Morgan worked on the tiny fruit fly called Drosophila melanogaster. This tiny fly shows variation in eye colour and can be easily crossed with other to show the flow trait.
