Biology - Online Test
Q1. Which phylum has bioluminescence as its well- marked feature?
Answer : Option B
Explaination / Solution:
The property of a living organism to emit light is known as bioluminescence and is well-marked in ctenophores.
Q2. The actual covering of testis is a dense, bluish white fibrous connective tissue sheath called
Answer : Option C
Explaination / Solution:
The covering of testis is a bluish white fibrous tissue sheath called tunica albuginea. Tunica albuginea also projects inside testis to form a thick incomplete vertical column called mediastinum.
Q3. Element located in centre of pophyrin ring of chlorophyll is
Answer : Option C
Explaination / Solution:
Chlorophyll molecule consists of a porphyrin ring and a long tail like chain of carbon and hydrogen. The centre of pophyrin ring is occupied by Mg ions.
Q4. Inheritance of skin colour in humans is an example of
Answer : Option C
Explaination / Solution:
Skin colour in human being is an example of polygenic inheritance. Eight different genes are involved in deciding the skin colour ranging between white to black.
Q5. Which of the following organisms not fix atmospheric nitrogen
Answer : Option C
Explaination / Solution:
Spirogyra is a filamentous alga. This alga does not fix atmospheric nitrogen. Anabaena, Nostoc and Oscillatoria can heterocyst that can fix atmospheric nitrogen.
Q6. In the human heart :
i. The valve between right atrium and right ventricle is tricuspid while valve between left atrium and left ventricle is mitral valve.
ii. Openings of the right and the left ventricles into the pulmonary artery and the aorta are guarded by semilunar valves.
iii. ‘Lub’ the first sound which is low pitched is caused by the closure of semilunar valves while ‘Dub’ the second sound which is high pitched is caused by the closure of bicuspid and tricuspid valves.
i. The valve between right atrium and right ventricle is tricuspid while valve between left atrium and left ventricle is mitral valve.
ii. Openings of the right and the left ventricles into the pulmonary artery and the aorta are guarded by semilunar valves.
iii. ‘Lub’ the first sound which is low pitched is caused by the closure of semilunar valves while ‘Dub’ the second sound which is high pitched is caused by the closure of bicuspid and tricuspid valves.
Answer : Option A
Explaination / Solution:
The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves whereas the second heart sound (dub) is associated with the closure of the semilunar valves.
Q7. The complex V is also known as
Answer : Option B
Explaination / Solution:
complex V or ATP synthase can be separated into 2 parts:
Fo - the portion embedded in the inner mitochondrial membrane and
F1-ATPase — the portion projecting into the matrix of the mitochondrion. This
is why the intact ATP synthase is also called the FoF1-ATPase.
Q8. Spraying of DDT produces pollution of
Answer : Option C
Explaination / Solution:
Spraying of DDT produces pollution of air, water and soil. DDT is used as pesticides in agricultural field. It is non-biodegradable and reach to water bodies to pollute it. Some DDT also remains present in air as mist.
Q9. Ancestors of mammals belongs to
Answer : Option A
Explaination / Solution:
The ancestor of mammals belongs to class Therapsida.Therapsida is a group of synapsids that includes mammals and their ancestors.
Q10. The complex formed by a pair of synapsed homologous chromosomes is called
Answer : Option D
Explaination / Solution:
The complex formed by a pair of synapsed homologous chromosomes is called a bivalentor a tetrad. However, these are more clearly visible at the Prophase1 of Meiosis-1.
