Class 12th Biology 2016 Set1 Outside Delhi Board Paper Solution
Why is the coding sequence of an enzyme ( β -galactosidase) a preferred selectable marker in comparison to the ones named above ?
Alternative selectable marker which differentiate recombinants from non-recombinants on the basis of their ability to produce colour in the presence of a chromogenic substrate. In this , a recombinant DNA is . inserted within the coding sequence of an enzyme, b galactosidase, which results into activation of the enzyme referred as insertional inactivation coding sequence for the enzyme b-galactosidase is preferred over antibiotic resistance genes because recombinants can be easily visualised.
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:- Do you think that reproductive health in our country has improved in the past 50 years? If yes, mention some such areas of improvement.
- Q:- Differentiate between gametogenesis from embryogenesis.
- Q:- Define ecological pyramids and describe with examples, pyramids of number and biomass.
- Q:- Suggest some methods to assist infertile couples to have children.
- Q:- Explain why meiosis and gametogenesis are always interlinked?
- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- How do ecologists estimate the total number of species present in the world?
- Q:- Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?
- Q:- What would be the molar concentration of human DNA in a human cell? Consult your teacher.
- Q:- Which is a better mode of reproduction sexual or asexual? Why?