CBSE 11TH BIOLOGY - Online Test
Q1.
Water breathing is more problematic than air breathing because :
i. water is 800 times more dense and hence holds much more oxygen than air does.
ii. since oxygen dissolved in water diffuses far more slowly than air therefore large quantity of water is required to be passed over the gills.
Answer : Option A
Explaination / Solution:
Water breathing is more problematic than air breathing because oxygen dissolved in water diffuses far more slowly than air therefore large quantity of water is required to be passed over the gills.
Q2. Oral contraceptive pills contain estrogen and progesterone, that prevent
Answer : Option B
Explaination / Solution:
Oral contraceptive pill contain estrogen and progesterone that prevents the release of secondary oocyte from ovary. The secondary oocyte develops to female egg or ovum. Use of these pills prevents the ovum formation.
Q3. 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.
Q4. 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.
Q5. 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.
Q6. 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.
Q7. 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.
Q8. 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.
Q9. Select the mismatched pair of the following :
Answer : Option D
Explaination / Solution:
Cortical nephron is about 25% of total nephrons. Glomerular filtration rate is 180 litre per day. Juxtamedullary nephron makes about 15% of total nephrons but lung do not removes 180 L of carbon dioxide per day.
Q10. Which of the following do not undergo any secondary growth?
Answer : Option B
Explaination / Solution:
Secondary growth in monocotyledonous roots is not observed as cambium is absent between xylem and phloem in a vascular bundle.
