CBSE 12TH BIOLOGY - Online Test
Q1. Which chromosome of human genome contains least number of genes?
Answer : Option A
Explaination / Solution:
There are 23 pairs of chromosome in human cells. The chromosome Y is the smallest and contain least number of gene (231) and chromosome 1 contain highest number of gene (2968).
Q2. Ovulation occurs on the ------ day of menstrual cycle.
Answer : Option D
Explaination / Solution:
The release of ovum from ovary during menstrual cycle is is called ovulation. Ovulation occurs in the middle of menstrual cycle that is on 14-16th day of start of menstrual cycle.
Q3. Which of the following factors influence the Hardy-Weinberg equilibrium?
i. Gene migration
ii. Genetic drift
iii. Mutation
iv. Reproduction
v. Genetic recombination
i. Gene migration
ii. Genetic drift
iii. Mutation
iv. Reproduction
v. Genetic recombination
Answer : Option B
Explaination / Solution:
The Hardy–Weinberg principle, also known as the Hardy–Weinberg equilibrium, model, theorem, or law, states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
These influences include mutation, selection, genetic drift, gene migration, gene flow, genetic recombination and meiotic drive.
Q4. The method in which male partner withdraw penis from vagina just before the ejaculation is called
Answer : Option D
Explaination / Solution:
The method in which male partner withdraws penis from vagina just before the ejaculation is called coitus interrupts. The meeting of ovum and sperm is avoided as sperms are not released.
Q5. Which one of the following techniques made it possible to genetically engineer living organisms?
Answer : Option B
Explaination / Solution:
Recombinant DNA technology, joining together of DNA molecules from two different species that are inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry.
This technique made it possible to genetically engineer the genome of living organisms.
It involves a number of procedures like identification, separation, cloning and introducing into suitable vector.
Q6. In human beings, fertilization of egg takes place in
Answer : Option D
Explaination / Solution:
Fertilisation of egg in human female takes place in oviduct or fallopian tube at the junction of ampullar-isthamus. Fertilized egg travels towards the uterus after that.
Q7. Hardy-Weinberg principle states that allele frequencies in a population are stable and is
Answer : Option D
Explaination / Solution:
The Hardy–Weinberg principle, also known as the Hardy–Weinberg equilibrium, model, theorem, or law, states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
Q8. The emergency contraceptives used to avoid possible pregnancy due to rape or unprotected intercourse is
Answer : Option A
Explaination / Solution:
The emergency contraceptives used to avoid possible pregnancy due to rape or unprotected sexual intercourse is a combination of progestogen and estrogen within 72 hours of sexual intercourse.
Q9. The methods involved in HGP have two major approaches, one approach focused on identifying all the genes that expressed as RNA called as Expressed sequence tags the other one is
Answer : Option D
Explaination / Solution:
The Human Genome Project (HGP) involved two major approaches; one approach called as Expressed sequence tags the other one is called sequence annotation.
DNA annotation or genome annotation is the process of
- (a) identifying the locations/segments of genes, coding regions and other specific locations that are of imporatance in a DNA sequence or genome and
- (b) associating relevant information with those locations/segments (e.g. determining what the identified genes do).
Q10. Cessation of menstrual cycle in female in female is known as
Answer : Option A
Explaination / Solution:
In female, menstrual cycle stops at about 50 years of age. This is called menopause. It is controlled by hormone released by ovum.
