Biology - Online Test
Q1. Bat and whales have ----- chambered heart.
Answer : Option D
Explaination / Solution:
Bat and whales have four chambered heart. Upper two chambers are called atrium and lower two chambers are called ventricle. All mammals have four chambered heart.
Q2. Conversion of spematid into a spermatozoan is called
Answer : Option B
Explaination / Solution:
Each spermatid undergoes metamorphosis to develop into spermatozoa or sperms having head, neck and tail. Acrosome is present at the tip of head that contain enzyme for hydrolysis of wall of ovum during fertilisation.
Q3. DNA differ from RNA in having
Answer : Option A
Explaination / Solution:
DNA differ from RNA in having Thymine. Thymine is absent in RNA. RNA contain uracil in place of thymine.
Q4. Female hetrogamety is present in
Answer : Option A
Explaination / Solution:
Female heterogamety is the formation of different types of gametes in female. Although male produce same types of gametes. In birds the female have ZW sex chromosome and male have ZZ sex chromosome.
Q5. Bacterial leaf blight of rice is caused by a species of
Answer : Option A
Explaination / Solution:
Bacterial leaf blight of rice is caused by bacterium Xanthomonas. The bacteria reduce the photosynthetic area of leaf and finally yield of rice is affected considerably.
Q6.
Match the following:
Animal
a) Paramecium
b) Pila
c) Scypha
d) Pheretima
circulation method
i) water canal system
ii) cyclosis
iii) blood flowing through vessels
iv) blood passing through sinuses
Answer : Option D
Explaination / Solution:
In Paramecium oxygen is carried by cyclosis, in Pila blood passing through sinuses carries oxygen, in Scypha water canal system is present and in Pheretima (earthworm) respiration is carried by blood flowing through vessels.
Q7. Earth is protected from ultra-violet radiations by means of
Answer : Option C
Explaination / Solution:
Ozone layer (stratospheric ozone) is a high concentration of ozone molecules about 30 to 50 km altitude (stratosphere). The main function of the ozone layer is to absorb the Sun's ultraviolet radiation, hence protecting the Earth from its harmful effects.
Q8. Lactic acid produced in muscle is sent to --------------------- to regenerate glucose.
Answer : Option A
Explaination / Solution:
Lactic acid is produced in muscle during insufficient oxygen in muscle cells. Lactic acid produced in muscle is sent to regenerate glucose during rest in presence of sufficient oxygen.
Q9. A cell divides every minute. It will fill a 100 ml beaker in one hour. How much time would it take to fill 50 ml beaker.
Answer : Option B
Explaination / Solution:
If a cell divide every minute, the number of cells get doubled at the end of each minutes. If a 100 ml beaker is filled in one hour, it will take 59 minute to fill 50 ml beaker.
Q10. Transfer of DNA into bacteria by phage is called as
Answer : Option C
Explaination / Solution:
Transfer of DNA into bacterial cell by phage or virus is called transformation. Phage kills the bacterium so called bacteriophage.
