CBSE 11TH BIOLOGY - Online Test
Q1. Sneha ceased to get smell of a perfume applied to her clothes but her friend Reema who passed by complimented her for the noticeable fragrance. This is an example of :
Answer : Option C
Explaination / Solution:
The sensory organs detect all types of changes in the environment and send appropriate signals to the CNS, where all the inputs are processed and analysed.
Q2. Bryophytes flourish is moist and shady environments because
Answer : Option D
Explaination / Solution:
These plants can live in soil but are dependent on water for sexual reproduction as they release antherozoids into water where they come in contact with archegonium to produce zygote. They usually occur in damp, humid and shaded localities.
Q3. The eukaryotic ribosomes are of
Answer : Option D
Explaination / Solution:
The eukaryotic ribosomes are 80S while the prokaryotic ribosomes are 70S. Here ‘S’ stands for the sedimentation coefficient; it indirectly is a measure of density and size.
Q4. In PSI, the reaction centre the chlorophyll a has an absorption peak at
Answer : Option B
Explaination / Solution:
In PS I the reaction centre chlorophyll a has an absorption peak at 700 nm, hence is called P700.
Q5.
Read the following statements :
i. The affinity of Hb for CO is 200 to 250 times more than its affinity for oxygen therefore CO competes with oxygen for binding to Hb.
ii. The result of this binding are a shift of oxygen-hemoglobin dissociation curve to the left and its alteration to a more hyperbolic shape.
Answer : Option C
Explaination / Solution:
The affinity of Haemoglobin is 200 to 250 times more than that of Oxygen, therefore, CO competes with Oxygen for binding to Hb. Due to this binding a shift of oxygen-hemoglobin dissociation curve to left and its alteration to a more hyperbolic shape.
Q6. The Prolactin inhibiting neurohormone is :
Answer : Option C
Explaination / Solution:
The Prolactin inhibiting neurohormone is dopamine. Dopamine is a neurotransmitter that helps control the brain’s reward and pleasure centers.
Q7. What is common among Liver fluke, Planarians and Tape worm?
Answer : Option B
Explaination / Solution:
All of them belong to Phylum Platyhelminthes and hence have dorso-ventrally flattened body and so, are called flatworms.
Q8. No cell could live without
Answer : Option B
Explaination / Solution:
Enzymes are bio-catalyst. All the metabolic biochemical reactions are carried out with the help of enzyme. No cell could survive without enzyme.
Q9.
Look at the following ECGs:
Answer : Option B
Explaination / Solution:
Both electro cardiogram (ECG) represents myocardial infarction in which heart do not receive the sufficient oxygen due to blockage of coronary artery.
Q10. Arrange the following in descending order based upon number of carbon atoms in Kreb cycle a) α-ketoglutaric acid b) citric acid c) Acetyl coA d) Succinic acid
Answer : Option C
Explaination / Solution:
In kerb cycle citric acid consists of 6C atoms ,α-ketoglutaric acid consist of 5C atoms, succinic acid consists of 4 C atoms and Acetyl co A consists of 2C atoms,
