CBSE 12TH BIOLOGY - Online Test
Q1. Rate of fluorescence in a titer plate in ELISA is
Answer : Option C
Explaination / Solution:
The rate of fluorescence in a titer plate in ELISA is directly proportional to antigens present in the sample. This indicates presence of pathogen in the sample also.
Q2. In India, medical termination of pregnancy was legalized in ------.
Answer : Option A
Explaination / Solution:
MTP (Medical termination of pregnancy) was legalized in 1971 in India with exception of female feticides after sex determination using Ultrasonography or other means.
Q3. Assertion: Ovule develops into mature seeds and ovary develops into fruits.
Reason: The fruits that develop only from ovary are called true fruits.
Reason: The fruits that develop only from ovary are called true fruits.
Answer : Option A
Explaination / Solution:
Ovule develops to form seeds and mature ovary develops into fruits. The fruits that develop only from ovary are called true fruits and those who contain other parts of flower are called false fruits.
Q4. Negative acceleration phase is caused due to
Answer : Option B
Explaination / Solution:
Negative acceleration phase is caused due to increase in environmental resistance. An environment have limited amount of resources after reaching climax phase negative acceleration occurs.
Q5. Ovary develops into fruit which develops a thick protective wall called
Answer : Option C
Explaination / Solution:
After fertilisation ovule changes into seeds and ovary itself change into fruits. The outer hard integuments of ovary form protective layer of fruit called pericarp followed by mesocarp and endocarp.
Q6. Antigen binding site in an antibody is found between
Answer : Option C
Explaination / Solution:
The antigen-binding (Fab) fragment is a region on an antibody that binds to antigens. It is composed of one constant and one variable domain of each of the heavy and the light chain.
Q7. Signaling between cells usually results in the activation of protein
Answer : Option B
Explaination / Solution:
Signaling between cells for transcription of m-RNA from DNA is controlled by an activation of protein kinases. It is present in cytoplasm of cells.
Q8. Gene banks are part of
Answer : Option C
Explaination / Solution:
Gene banks are part of ex situ conservation of plants or plant parts. In ex situ conservation, plants parts are maintained in laboratory condition. In in situ conservation, plants are kept in natural condition with protection.
Q9.
Most of the alien species do not establish in new areas but some do likely because:
i. they are released from limitations imposed by their native predators and competitors
ii. they might outcompete the native species
Answer : Option C
Explaination / Solution:
Invasive Non- Native Species are accidental or intentional introduction of exotic species to new areas. species that are non-native to a particular area can sometimes spread very quickly. Most do not establish or expand, but some do - likely because they are " released" from limitations imposed by their native predators, parasites, and competitors. in todays globalizing world, invasive species have become perhaps the second- worst threat to native biota. They might outcompete with native species.
Q10. Antrum is the cavity of
Answer : Option A
Explaination / Solution:
Ovary contains large number of Graafian follicle that maturates to produce ovum or egg. A small cavity is present in Graafian follicle called antrum.
