CBSE 12TH BIOLOGY - Online Test
Q1. Phosphorus will not make part of
Answer : Option A
Explaination / Solution:
Phosphorus is not present in amino acids. Nucleic acids, ATP and Teeth contain phosphorus. Amino acids polymerases to form protein.
Q2. The organization set up by Indian government for making decisions regarding validity of GM research is
Answer : Option C
Explaination / Solution:
The Genetic Engineering Appraisal Committee (GEAC) is the apex body constituted in the Ministry of Environment and Forests under 'Rules for Manufacture, Use, Import, Export and Storage of Hazardous Microorganisms/Genetically Engineered Organisms or Cells 1989', under the Environment Protection Act, 1986.
Q3. First human population explosion took place due to
Answer : Option D
Explaination / Solution:
First human population explosion occurred due to agriculture system in which people start living together in colonies. They felt the need for more labour powere to perform different agricultural practices.
Q4. Assertion: The portion of embryonal axis above the level of cotyledon is epicotyl.
Reason: Epicotyl terminates at with lower end in the radicle or root tips.
Reason: Epicotyl terminates at with lower end in the radicle or root tips.
Answer : Option B
Explaination / Solution:
In embryo, the portion of embryonical axis above the level of cotyledon is epicotyl which terminates with Plumule or stem tips above the above the level of cotyledons,
Q5. How will you represent a stable population?
Answer : Option C
Explaination / Solution:
Stable populations are theoretical models widely used by demographers to represent and understand the structure, growth and evolution of human populations. By definition, stable populations have age-specific fertility and mortality rates that remain constant over time.
Age pyramids generally shows age distribution of male and female in combined diagram. The stble population shows a bell shaped polygon.
Q6. Which one of the following is a bridge linking childhood and adulthood?
Answer : Option A
Explaination / Solution:
Adolescence is a bridge linking childhood and adulthood. It is accompanied by several biological and behavioral changes. Thus, it is a very vulnerable phase of mental and psychological development.
Q7. Why are UGA, UAG and UAA called termination codons?
Answer : Option D
Explaination / Solution:
The three codons, UAA known as ochre, UAG as amber and UGA as opal, that do not code for an amino acid but act as signals for the termination of protein synthesis. So they also Known bas termination codon.
They are not represented by any tRNA and termination is catalysed by protein release factors.
Q8. The management of animal for milk and its product for human consumption is called
Answer : Option A
Explaination / Solution:
Dairying or dairy management is the process and system that increase yield and increase the quality of milk. Milk yield is primarily dependent of quality of breeds in the farms.
Q9. Humans have increased extinction rate by a factor of
Answer : Option D
Explaination / Solution:
Various human activities like pollution, deforestation, urbanization, industrialization have increased the extinction rate of various organisms by a factor of 1000.
Q10. Assertion: Fallopian tubes ends in a funnel shaped structure called the infundibulum.
Reason: Infundibulum is covered with small finger like projections called fimbriae.
Answer : Option A
Explaination / Solution:
Fallopian tube extends from the left and right superior corners of the uterus to the edge of the ovaries. It end in a funnel shaped structure called Infundibulum which is covered with small finger like projections called fimbriae.
