Class 12th Biology 2016 Set3 Delhi Board Paper Solution
Question 17
Give an example of an autosomal recessive trait in humans. Explain its pattern of inheritance with the help of a cross.
Answer
Sickle Cell Anaemia is an autosomal recessive trait in humans. The genes responsible for this disease are located in autosomes. The disease being recessive the trait should be present in homozygous condition, for it to express.
People who carry a single copy of the gene are clinically normal but are carriers of the disease and can pass on the defective gene to their subsequent generation.
Popular Questions of Class 12th biology
- Q:- What is spermatogenesis? Briefly describe the process of spermatogenesis.
- Q:- Why is reproduction essential for organisms? Answer
- Q:- Write a short note on
(a) Adaptations of desert plants and animals
(b) Adaptations of plants to water scarcity
(c) Behavioural adaptations in animals
(d) Importance of light to plants
(e) Effect of temperature or water scarcity and the adaptations of animals. - Q:- With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.
- Q:- What is DNA fingerprinting? Mention its application.
- Q:- Describe the structure of a seminiferous tubule.
- Q:- What is oogenesis? Give a brief account of oogenesis.
- Q:- What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
- Q:- With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
- Q:- Explain the Law of Dominance using a monohybrid cross.
Recently Viewed Questions of Class 12th biology
- Q:- In the medium where E. coli was growing, lactose was added, which induced the lac operon. Then, why does lac operon shut down some time after addition of lactose in the medium?
- Q:- Draw a labeled diagram of male reproductive system.
- Q:- What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
- Q:- What is oogenesis? Give a brief account of oogenesis.
- Q:- Identify each part in a flowering plant and write whether it is haploid (n) or diploid (2n).
(a) Ovary _______________
(b) Anther _______________
(c) Egg _________________
(d) Pollen__________________
(e) Male gamete _______________
(f ) Zygote ___________________ - Q:- Write a short note on
(a) Adaptations of desert plants and animals
(b) Adaptations of plants to water scarcity
(c) Behavioural adaptations in animals
(d) Importance of light to plants
(e) Effect of temperature or water scarcity and the adaptations of animals. - Q:- Is sex education necessary in schools? Why?
- Q:- The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?
- Q:- What are sacred groves? What is their role in conservation?
- Q:- How is biodiversity important for ecosystem functioning?