Class 12th Biology 2017 Set2 Delhi Board Paper Solution
Name the hormones secreted and write their functions :
(i) By corpus luteum and placenta (any two).
(ii) During follicular phase and parturition
(i) Hormones secreted by corpus luteum
â Progesterone It converts the endometrium to its secretory stage and prepares the uterus for implantation.
â Oestradiol It acts as a growth hormone for tissue of the reproductive organs, supporting the vaginal lining, endometrium, etc. Hormones secreted by placenta â hCG Human Chorionic Gonadotropin. It stimulates and maintains the corpus luteum to secrete progesterone until the end of pregnancy.
â hCS Human Chorionic Somatomammotropin. It stimulates the growth of mammary glands during pregnancy.
(ii) Hormone secreted during follicular phase
â FSH Follicular Stimulating Hormone. It stimulates the ovarian follicles to secrete oestrogen. Hormone secreted during parturition
â Relaxin It increases the flexibility of pubis symphysis and helps in the dilation of uterine cervix during labour
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:- Explain the Law of Dominance using a monohybrid cross.
- 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?