Class 12th Biology 2018 Set1 Delhi Board Paper Solution
Explain the role of the ‘first trophic level’ in an ecosystem.
Ecological pyramid is given by Charles Elton in 1927 which is the graphical representation of the numbers or biomass and accumulated energy at each trophic level in the food chain. The base of the each pyramid represents the producers or first trophic level while the apex represents the next trophic levels like tertiary or high level consumers and other consumer trophic levels in between them.
first trophic level is the producer level like green plants (grasses) in the ecosystem which makes food on their own by the help of photosynthesis process. Producer level is important to because it is the key to the further trophic levels. The upper trophic levels are dependent on the first trophic level for the food and energy. Like Herbivores are the second trophic level which feeds on grasses (first trophic level) and then herbivores are eaten by the further trophic level organisms like carnivores and so on. So, they are interconnected.
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:- What is oogenesis? Give a brief account of oogenesis.
- Q:- Describe the structure of a seminiferous tubule.
- 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:- List two essential roles of ribosome during translation.
- Q:-
Practise drawing various animals and plants.
- Q:- Using a Punnett square, work out the distribution of phenotypic features in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.
- Q:- What initiatives were taken for reducing vehicular air pollution in Delhi? Has air quality improved in Delhi?
- Q:- Distinguish between
(a) Grazing food chain and detritus food chain
(b) Production and decomposition
(c) Upright and inverted pyramid
(d) Food chain and Food web
(e) Litter and detritus
(f) Primary and secondary productivity - Q:- What is apiculture? How is it important in our lives?
- Q:-
Why is the Human Genome project called a mega project?
- Q:- Which one of the following has the largest population in a food chain?
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers - Q:- Do you think microbes can also be used as source of energy? If yes, how?
- Q:- How do ecologists estimate the total number of species present in the world?