Zoology - Online Test
Q1. 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.
Q2. Genetic drift is found in
Answer : Option B
Explaination / Solution:
Genetic drift is found in small population with or without mutated genes. Loss of some member of species having small population leads to decrease in variation called genetic drift.
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. Natural method of birth control in which the couples avoid from coitus from day 10 to 17 of menstrual cycle is called
Answer : Option C
Explaination / Solution:
periodic abstinence is a natural method of birth control in which the couples avoid from sexual intercourse form day 10 to 17 of menstrual cycle during which ovulation takes place in female.
Q5. 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.
Q6. What does "lac" refer to in what we call the lac operon?
Answer : Option D
Explaination / Solution:
The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available.
Q7. Egg released by the Graafian follicle is surrounded by
Answer : Option A
Explaination / Solution:
One of the two ovary release one egg by the Graafian follicle. The egg released is surrounded by two layers called zonapellucida and Vitelline membrane as protective layer.
Q8. Floods can be checked by
Answer : Option B
Explaination / Solution:
Floods can be checked by reforestation. The roots of plants binds the soil and act as barrier in flow of flood water to reduce its current speed.
Q9. 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.
Q10. Which one of the followings is incorrect about genetic drift?
Answer : Option B
Explaination / Solution:
Genetic drift is significant only in small population. Larger population has more variation and more species. Loss of some member of that species does not reduce variation essential for evolution.
