CBSE 11TH BIOLOGY - Online Test
Q1. Genetic material for retrovirus is
Answer : Option C
Explaination / Solution:
The virus in which genetic material is RNA are called retrovirus. In this virus reverse transcription takes place to form DNA that synthesis proteins.
Q2. A cell immersed in a solution increase in volume. The solution is
Answer : Option A
Explaination / Solution:
The behaviour of the plant cells (or tissues) with regard to water movement depends on the surrounding solution. If the external solution is more dilute than the cytoplasm, it is hypotonic Cells swell in hypotonic solutions.
Q3. Magnesium is component of
Answer : Option A
Explaination / Solution:
It is absorbed by plants in the form of divalent Mg2+. Magnesium is a constituent of the ring structure of chlorophyll and helps to maintain the ribosome structure.
Q4. ____ from pharynx is conveyed into oesophagus by _____ .
Answer : Option B
Explaination / Solution:
Bolus from pharynx is conveyed into oesophagus by deglutition. Bolus is the semisolid chewed food mixed with saliva in mouth. The food from pharynx passed to oesophagus by swallowing.
Q5. Secondary plant products are of great use in commerce in making
Answer : Option C
Explaination / Solution:
Many secondary plant products are of great use in commerce in making drug and perfumes. The primary product of plants is carbohydrates synthesized during photosynthesis.
Q6. The stacks of closely packed thylakoids is called
Answer : Option D
Explaination / Solution:
Granum : A stacked membranous structure within the chloroplasts of plants and green algae that contains the chlorophyll and is the site of the light reactions of photosynthesis. The saclike membranes that make up grana are known as thylakoids.
Q7. In Molluscs, the rasping feeding organ is
Answer : Option D
Explaination / Solution:
The mouth of molluscs contains a file-like rasping organ for feeding, called radula.
Q8. Astral body are formed of
Answer : Option C
Explaination / Solution:
Astral body are formed of microtubules. Astral bodies are produced by centriolar division proir to start of during cell division and attach with centromere of the chromosome during.
Q9. Living organisms are classified because of
Answer : Option C
Explaination / Solution:
Living organisms are classified according to certain criteria for easy identification and study of organism. As the number of organisms are very large, it is not possible to study about each and every organism without classification.
Q10. The correct order of digestive system of frog is
Answer : Option A
Explaination / Solution:
The digestive system of frog begins from the mouth which opens into the buccal cavity that leads to the oesophagus through pharynx. Oesophagus is a short tube that opens into the stomach which in turn continues as the intestine and then rectum. The rectum finally opens outside by the cloaca through cloacal aperture.
