What is primary productivity? Why does it vary in different types of ecosystems?
Primary productivity is the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis. Primary productivity varies in different types of ecosystem because it depends on:
a) The plant species inhabiting the area.
b) The variety of environmental factors.
c) The photosynthetic capacity of plants.
d) The availability of nutrients.
Explain Darwinian theory of evolution with the help of one suitable example. State the two key concept of the theory.
Draw a sectional view of human ovary and label the different follicular stages, ovum and Corpus luteum.
Draw a sectional view of human ovary and label the different follicular stages, ovum and Corpus luteum.
Study the graph given below and answer the questions that follow:
(i) Write the status of food and space in the curves (a) and (b).
(ii) In the absence of predators, which one of the two curves would appropriately depict the prey population?
(iii) Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line.
In which phase of the cell cycle does replication occur in Eukaryotes? What would happen if cell-division is not followed after DNA replication?
Mention any three characteristics of Neanderthal man that lived in near east and central Asia.
How is 'oogenesis' markedly different from 'spermatogenesis' with respect to the growth till puberty in the humans?