CBSE 12TH BIOLOGY - Online Test
Q1. Human genome project was 13 year project co-ordinated by
Answer : Option A
Explaination / Solution:
The Human Genome Project was a 13-year-long, publicly funded project initiated in 1990 with the objective of determining the DNA sequence of the entire euchromatic human genome within 15 years.
It was co-ordinated by U. S. Department of energy and National institute of health.
At any given time, approximately 200 labs in the United States were funded by either the National Institutes of Health or the U.S. Department of Energy to support these efforts.
Later on, Welcome trust of U.K becomes the major partner of this project.
Q2. The cellular layer that disintegrates and regenerates again and again is
Answer : Option B
Explaination / Solution:
Endometrium is the inner lining of uterus which disintegrates and regenerates again and again during menstrual cycle.
Q3. Which of the following is a source of variation in a population?
Answer : Option D
Explaination / Solution:
The source of variation includes the mutation, crossing over during cell division and inherited genetic traits may also change due to mutation to create variation.
Q4. In IVF technique, fusion of ovum and sperm take place in
Answer : Option C
Explaination / Solution:
In vitro fertilisation technique involves fertilisation outside the body in culture media followed by embryo transfer in fallopian tube or uterus.
Q5. In human genome project, which chromosome was sequenced at last?
Answer : Option B
Explaination / Solution:
Chromosome 1 is the final one to be mapped out in Human Genome Project. The chromosome carries an estimated 3,141 genes that manufacture proteins, making it one of the most gene-rich chromosomes.
Chromosome 1 is the largest human chromosome, containing about 8% of the entire genome. That's six times longer than its smallest sibling, chromosome 21. Work on this monster started a couple of years after researchers cracked into some of the other chromosomes. It was completed on may 2006.
Q6. Testosterone is secreted by
Answer : Option D
Explaination / Solution:
Testosterone hormone help in release of sperm from testis. This hormone is released by leydig cells present in between seminiferous tubules of testis.
Q7. Phenomenon of “Industrial melanism” demonstrates
Answer : Option C
Explaination / Solution:
The organism surviving in industrial area having polluted soil, air and water undergo changes in skin colour and other traits to adjust in given surroundings. This is a type of natural selection.
Q8. Surgical method of contraception
Answer : Option A
Explaination / Solution:
In surgical method fallopian tubes of female and vas deference of male is cut and tide to prevents insemination and ovulation.
Q9. The international rice genome sequencing project begin in
Answer : Option B
Explaination / Solution:
The International Rice Genome Sequencing Project (IRGSP) began in September 1997, at a workshop held in conjunction with the International Symposium on Plant Molecular Biology in Singapore. Scientists from many nations attended the workshop and agreed to an international collaboration to sequence the rice genome.
Q10. Menstrual cycle is repeated at an average interval of
Answer : Option C
Explaination / Solution:
In human female menstrual cycle is repeated at the interval of 28/29 days from menarche to menopause. Menstrual cycle gets stopped during pregnancy.
