CBSE 12TH BIOLOGY - Online Test
Q1. The superiority of the hybrid over either parent in one or more traits is
Answer : Option D
Explaination / Solution:
Heterosis, hybrid vigor, or outbreeding enhancement, is the improved or increased function of any biological quality in a hybrid offspring. The adjective derived from heterosis is heterotic
Hybrid obtained from two different plants have one or more traits superior than either of parents.
Q2. Biodiversity is most frequently quantified as
Answer : Option D
Explaination / Solution:
Biodiversity is the presence of diverse kinds of living organisms in a particular habitat. It is most frequently quantified as number of species in particular geographical region.
Q3. In some plants anther and stigma mature at same time this condition is called
Answer : Option D
Explaination / Solution:
Homogamy – In this case the anther and stigmas of a bisexual flower mature simultaneously. The pollen grains reach the mature stigma either by contact, wind, gravity, rain drop or even insects. Self pollination brought about by contact is called direct autogamy and remaining agencies perform indirect autogamy.
Q4. Seminal plasma in human males is rich in
Answer : Option C
Explaination / Solution:
Seminal plasma along with sperms forms the semen. The seminal plasma provides nourishment to sperms and rich in fructose and calcium ions.
Q5. Monohybrid ratio is
Answer : Option D
Explaination / Solution:
Monohybrid ratio is the ratio of different phenotypic traits obtained on hybridizing single pair of trait. It is 3:1. When tall pea plant is crossed with dwarf, the offspring obtained are in 3/4 tall and 1/4 dwarf.
Q6. Ethanol is commercially produced through a particular species of
Answer : Option A
Explaination / Solution:
Saccharomyces is an yeast which is used to ferment sugar to produce ethanol in absence of oxygen or by anaerobic respiration.
Q7. A sure indicator of air pollution is
Answer : Option A
Explaination / Solution:
Bioindicators are living organisms that respond in an especially clear way to a change in the environment.
The lichens are useful bioindicators for air pollution, espeially sulfur dioxide pollution, since they derive their water and essential nutrients mainly from the atmosphere rather than from the soil.
The polluted air have very less or no lichens.
Q8. The period of pregnancy is known as
Answer : Option B
Explaination / Solution:
The duration from implantation of fertilised eggs to uterus till birth of well-developed baby is called gestation period. It is about nine months in human beings.
Q9. Protein encoding gene expressed in heterologous host is called as
Answer : Option C
Explaination / Solution:
Recombinant Protein is a protein encoded by a gene — recombinant DNA — that has been cloned in a system that supports expression of the gene and translation of messenger RNA (see expression system). Modification of the gene by recombinant DNA technology can lead to expression of a mutant protein. Protein encoding genes are commonly described as structural or regulatory. Structural gene encodes enzymes and structural protein.
Q10. Which theory explains the origin of universe
Answer : Option A
Explaination / Solution:
Origin of universe is explained by big bang theory. According to this theory, whole universe was concentrated into single sphere. Due to same unknown reason, there was explosion in it that forms different galaxies still moving away from each other.
