CBSE 11TH BIOLOGY - Online Test
Q1. The organism that completely lack a cell wall and are smallest living cell know, can survive without oxygen is
Answer : Option D
Explaination / Solution:
Mycoplasmas are group of organism that lack cell wall and are smallest living organisms. They can survive without oxygen. Mycoplasmas are also called as PPLO (pleuro pneumonia like organism).
Q2. In animal cells, Cytokinesis takes place by furrow deepening centripetally and formation of two daughter cells. This method is known as
Answer : Option D
Explaination / Solution:
In animal cell, cytokinesis takes place by furrow which appears at the margins of plasma membrane and gradually deepens towards the central part of the cell. Ultimately the furrow divides the cell into two halves. This method of cytokinesis is known as cleavage cytokinesis.
Q3. Plant and animal specimens may also be preserved as dry specimens in
Answer : Option A
Explaination / Solution:
Plant and animal specimens may also be preserved as dry specimens in museums. Hence, the correct option is Museum.
Q4. Blood plasma contains ----------------- % water.
Answer : Option B
Explaination / Solution:
Blood consists of blood plasma, formed cells ( RBC, WBC, Platelets) along with sugar, proteins etc. Blood plasma contains about 90% water with a number of salts and few circulating hormones.
Q5. An alkaloid widely used in plant breeding for doubling the chromosome number also known as ‘mitotic poison’ is
Answer : Option C
Explaination / Solution:
Colchicine is an alkaloid used in plant breeding for doubling of chromosomes by inhibiting cytokinesis. It is also called as mitotic poison. It is extracted from the bark of plant belonging to genus Colchicum.
Q6. Which serve as quick referral systems in taxonomical studies?
Answer : Option A
Explaination / Solution:
Museums have collections of preserved plant and animal specimens for study and reference. Manuals are useful in providing information for identification of names of species found in an area. Monographs contain information on any one taxon. Hence, the correct option is Herbarium.
Q7. Material used for study of mitotic cell division in class room is
Answer : Option A
Explaination / Solution:
The most common material used for study of mitosis cell division in class room is onion root and broad bean root tip. They can be grown quickly and in all seasons. Also they are esier to handle with and divisional stages are completed quickly.
Q8. A grown up cell divides when a maximum size is attained and which disturb the
Answer : Option B
Explaination / Solution:
A disturbance in the nucleoplasmic ratio will cause the cell to divide and attain stable ration which is 1. If it is less or more than 1 the cell becomes unstable and divides agin.
Q9. Specimens are preserved in the containers or jars in preservative solutions in
Answer : Option A
Explaination / Solution:
Specimens are preserved in the containers or jars in preservative solutions in museum.
Q10. Which type of cell division helps in regeneration?
Answer : Option A
Explaination / Solution:
Regeneration is the ability of organism to regain its lost body parts. Regeneration is achieved by mitotic cell division to maintain same number of chromosomes in the cell.
