CBSE 12TH BIOLOGY - Online Test
Q1. What is not true for genetic code?
Answer : Option B
Explaination / Solution:
Genetic code is unambiguous, universal and degenerate. Codon in mRNA is read in contiguous fashion without any gap. There are no punctuations during reading of Codon.
Q2. “Blue revolution” is related to
Answer : Option D
Explaination / Solution:
Blue revolution is related to fish production. This revolution is brought about by using aquaculture and pisciculture on the line of green revolution for wheat production.
Q3. The newest addition to India’s national parks is:
Answer : Option D
Explaination / Solution:
Located in the Himalayan foothills, it is contiguous with the Royal Manas National Park in Bhutan. The park is known for its rare and endangered endemic wildlife such as the Assam roofed turtle, hispid hare, golden langur and pygmy hog. It is established in 1990.
Q4. Urethra is an 8 to 10 inch long muscular tube. The urethra passes through the prostate glands and end at the
Answer : Option C
Explaination / Solution:
Semen passes from the ejaculatory duct to the exterior of the body via urethra. The urethra passes through the prostate glands and ends at the external urethral orifice.
Q5. A somatic cell in human male contains
Answer : Option B
Explaination / Solution:
Somatic cells in human male contain 22 pairs of autosomes and 1 pair (XY) of sex chromosome. Y chromosome is smaller in size and do not have allelomorphic pair of X chromosome. So, only one sex-linked gene is available for each character.
Q6. Agriculture by using only biofertilizers is called
Answer : Option C
Explaination / Solution:
Organic farming is the practice of agriculture in which no chemical substance is used as fertilizers, pesticides or insecticides. Biofertilizers are used to provide nutrient.
Q7. The metal which is inert and when swallowed remains non-toxic but becomes severely toxic when inhaled in volatile form:
Answer : Option A
Explaination / Solution:
Mercury is inert and when swallowed remain non-toxic but becomes severely toxic when inhaled in volatile form. It enters the respiratory system and riches to lungs to cause lung cancer.
Q8. The particles used to coat with DNA in Biolistic gun is of
Answer : Option B
Explaination / Solution:
DNA is coated with tungsten before used in biolistic gun for inserting the DNA directly into target cells for obtaining particular protein.
Q9. What was the mixture of gases used in chamber marked A?
Answer : Option C
Explaination / Solution:
The gases used in Urey and Miller experiment in chamber marked A are Methane , ammonia , hydrogen , and water
Q10. Somaclonal variation appears in plants
Answer : Option D
Explaination / Solution:
Tissue culture is mode of vitro propagation of large number of plantlets in short interval of time. During tissue culture, plants parts are kept in nutrient medium along with required hormones. Some variation arises in plants body although having same genetic traits.
