Class 12th Biology 2015 Set2 Delhi Board Paper Solution
A teacher wants his/her students to find the genotype of pea plants bearing purple coloured flowers in their school garden. Name and explain the cross that will make it possible.
Purple colour of flowers is a dominant phenotype in pea plants. The genotype of such plants can be determined by a test cross.
Test Cross
When an F1 hybrid is crossed with its homozygous recessive parent, it is known as test cross.
Test cross determines whether the dominant character is coming from homozygous dominant genotype or heterozygous genotype, e.g. purple flower coming from PP or Pw.
In this cross, plant with purple-coloured flowers is crossed with plant with white-coloured flowers, which will always have homozygous recessive genotype.
Thus, the genotype of pea plant bearing purple-coloured flowers in the school garden can be Pw or PP.
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?