CBSE 12TH BIOLOGY - Online Test
Q1. Golden rice is enriched in
Answer : Option A
Explaination / Solution:
Golden rice is a form of rice with biosynthesis of beta-carotene (a form of vitamin A). In other words, golden rice is produced through genetic engineering. Beta-carotene gives golden rice its “golden” or “yellow” coloring.
Golden rice is rich in beta-carotene. It is also easily processed by your digestive system.
Q2. Reproductive health includes
Answer : Option A
Explaination / Solution:
The different aspects of reproductive phase that includes knowledge and precaution against STds, different available contraceptive methods as well as assisted reproductive technologies for infertile couples.
Q3. Select the mismatched pair out:
Answer : Option B
Explaination / Solution:
The term ecology, silent spring and ecosystem were coined by Haeckel, Carson and Tansley respectively. The term biome was not coined by Hutchinson.
Biome, as coined and applied by Clements, was not the ecosystem.
Q4. Pathogenic bacterium that cause typhoid fever in human being is
Answer : Option B
Explaination / Solution:
Typhoid fever in human being is caused by Salmonella typhi. The pathogen enters to small intestine through food and contaminated water and migrates to other organs through blood.
Q5. By which bonds the purine & pyrimidine pairs of Complementary Strands of DNA held together?
Answer : Option D
Explaination / Solution:
Three hydrogen bonds form between guanine and cytosine. Two hydrogen bonds form between adenine and thymine or adenine and uracil. Complementary pairs always involve one purine and one pyrimidine base.
Q6. Producers in the aquatic ecosystem are :
Answer : Option A
Explaination / Solution:
Phytoplanktons are small floating photosynthetic unicellular plant. In the aquatic ecosystem phytoplankton are producers that fix solar energy by the process of photosynthesis.
Q7. Cloning is not meant for
Answer : Option C
Explaination / Solution:
Cloning is the method of increasing the number of individual having similar genetic organization. It is not a means of reproduction or production of the organism.
Q8. Biological diversity level that doesn’t exist is:
Answer : Option C
Explaination / Solution:
Biological diversity level is classified as alpha, beta and gamma. Delta is not a biological diversity level.
The terms alpha, beta, and gamma diversity were all introduced by R. H. Whittaker to describe the spatial component of biodiversity. Imagine that you have a landscape containing of a number of separate sites and habitats. Alpha diversity is just the diversity of each site (local species pool). Beta diversity represents the differences in species composition among sites. Gamma diversity is the diversity of the entire landscape (regional species pool).
Q9. The flower which possesses both androecium and gynoecium is called perfect or:-
Answer : Option D
Explaination / Solution:
Bisexual flower conation both male and female reproductive parts i.e. sepals and petals. These flowers are also called as monoecious or hermaphrodite.
Q10. External genitalia of human female is called as
Answer : Option D
Explaination / Solution:
The external genitalia of human female is called vulva. Vulva includes mons pubis, labia majora, labia minora, hymen and clitoris.
