LEARNOGRAPHY

  1. Add a short note on Pyramid of biomass , energy and number . Ans:-         The relationship between numbers, biomass, energy or bio productivity of different trophic levels in an ecosystem can be represented by a pyramid known as the ecological pyramid or Eltonian pyramid. The ecological pyramids show the energy flow in the system . A biomass pyramid is the representation of total living biomass or organic matter present at different trophic levels in an ecosystem. Biomass is calculated as the mass of living organisms present at each trophic level in a given sample size. It can be represented as dry weight in grams or calories per unit area. A bomb calorimeter is used to measure biomass. Trophic level is the specific place that a living organism occupies in a food chain. In a biomass pyramid, producers (1 st  trophic level) are at the base, followed by herbivores (primary consumers) and then carnivores (secondary and tertiary consumers) at the top...

 ● Ecosystem is the interaction of living things among themselves and with their surrounding environment. ● There are two basic ecosystems − terrestrial and aquatic. Structure of Ecosystem ● The interactions between the various biotic and abiotic factors of an ecosystem lead to the maintenance of the ecosystem. ● Stratification is the vertical distribution of the different species occupying the different levels. For example, trees occur at a higher level then shrubs. ● The various aspects taken into consideration to study the functioning of ecosystem are: ○ Productivity ○ Decomposition ○ Energy flow ○ Nutrient cycling Productivity ● A constant supply of sunlight is required for the proper functioning of any ecosystem. ● The amount of biomass produced per unit area over a time period by plants during photosynthesis is defined as the primary productivity​. ● It is expressed as weight (g −2) or energy (Kcal m−2). ● Productivity can be mainly divided into gross primary productivity (GP...

  Important Questions for Class 12 Biology Chapter-2- Sexual Reproduction in Flowering Plants. Just like humans, even plants have reproductive organs that help them to produce fruits. Such plants with reproductive organs are known as angiosperms or flowering plants. Sexual reproduction in flowering plants involves an important phenomenon called pollination. The pollen grains from the male flower are transferred to the stigma of the female flower. These pollens then travel through the pollen tube into the female reproductive tract and release the pollens, thereby, proceeding the reproduction process. Mentioned below are the important questions on sexual reproduction in flowering plants for Class 12. The answers are also provided for reference. Very Short Answer Type Questions Q.1. What are the component cells of the egg apparatus in an embryo sac? A.1.  An egg apparatus consists of: One egg cell Two synergids Q.2. Which part of gynoecium determines the compatible nature of poll...