CBSE 12TH BIOLOGY - Online Test
Q1. Flagellated, motile asexual reproductive structure are called
Answer : Option A
Explaination / Solution:
A number of simple organism produce single or multi-flagellated spores called zoospores. Water is essential for this mode of reproduction. Aplanospores are non-flagellated spores.
Q2. AIDS can be detected by
Answer : Option B
Explaination / Solution:
A series of blood screenings are performed to test for HIV. The enzyme-linked immunosorbent assay (ELISA), also known as an enzyme immunoassay (EIA), is the first test that your healthcare provider will order to screen for HIV. ELISA, like the Western blot test, detects HIV antibodies in your blood.
Q3. Name the fluid from which foetal cells are obtained for chromosomal analysis.
Answer : Option A
Explaination / Solution:
Amniotic fluid is used to obtain foetal cells for chromosomal analysis. This method is misuse as it can determine the sex of foetus. The fluid is collected form the surrounding of growing foetus.
Q4. Exponential growth pattern in a population results into
Answer : Option D
Explaination / Solution:
Exponential growth pattern in population results into j-shaped curve. During exponential growth faster growth occurs and j-shaped curve is formed when time v/s growth is drawn.
Q5. Where memory cells are formed?
Answer : Option D
Explaination / Solution:
Memory cells are formed in lymphocytes of WBC. Immunization against the particular disease based on the function of memory cell induced due to mild, heat killed pathogen administrated during immunization.
Q6. What does A & B represent?
Answer : Option C
Explaination / Solution:
In figure above, A represent helicase and B represents single strand binding protein. These structures are formed during semi-conservative replication of DNA.
Q7. Conditions favouring decomposition are
Answer : Option C
Explaination / Solution:
Decomposition rate accelerate at high temperature and high humidity. At higher temperature and high humidity number of decomposer increases substantially that accelerate the decomposition.
Q8. Which one of the following is commonly used in transfer of foreign DNA into crop plants?
Answer : Option B
Explaination / Solution:
Genetically modified foreign DNA is transferred into crops plants through a vector. Agrobacterium tumefaciens is most common bacterium used for this purpose.
Q9. Identify the odd combination of the habitat and the particular animal concerned
Answer : Option D
Explaination / Solution:
Dachigam National Park is located 22 kilometers from Srinagar, Jammu and Kashmir. It covers an area of 141 km. The name of the park literally stands for "ten villages" which could be in memory of the ten villages that were relocated for its formation.
The main animal species that Dachigam is known for is the hangul, or the Kashmir stag.
Q10. Bidder’s canal is meant for the passage of
Answer : Option C
Explaination / Solution:
Bidder’s canal is present in male reproductive system. It is meant for passage of sperms during coitus.
