Class 12th Biology 2016 Set1 Outside Delhi Board Paper Solution
Taking an example of a small pond, explain how the four components of an ecosystem function as a unit.
The four component in an ecosystem functions as unit as follows:
1) Productivity: This is represented by the autotrophic phytoplanktons same algae and the floating and marginal plants found at the edges.
2) Energy flow: Represented by water in the pond with all the dissolved organic and inorganic substances, the solar energy and other climate conditions that regulate the rate of function of the pond. The consumers are represented by the 200 planktons and bottom dwelling forms.
3) Decompositions: The decomposers are the fungi bacteria and flagellates abundant at the bottom of the pond.
4) Nutrient cycling: The pond ecosystem converts inorganic material into organic material using solar energy by the autotrophs. The autotrophs are eaten up by hetrotrophs, decomposition and mineralisation of dead matter for resuse by autotrophy is done by decomposers.
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:- Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.
- 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.