Answer:
Darwin proposed the theory of natural selection to explain the process of evolution. According to Darwin’s theory of natural selection, all organisms have the potential to reproduce limitlessly irrespective of the fact that each species maintain a constant density over time. However, the struggle for existence, i.e. the competition among individuals for available resources to survive and reproduce, put a check on species density (D) and maintains it at a constant level (B). Survival of fittest is unequal ability of individuals to survive and reproduce based on suitability of their inherited characters to prevailing environmental conditions (A). It imparts the reproductive advantage to certain organisms which account for major part of the gene pool of the species. Thus, natural selection favors the individual with survival and/or reproductive advantage over others under existing environmental condition (E). Thus, the correct answer is option C.
Evolution of a species acts on the population of the species
Trees are very important natural resources. They are the source of food, shelter and habitat. We get various woods, timber , fodder from the forest. Trees hold the soil firmly. Forests helps in conducting water cycle. If trees are cut down then environmental pollution will increase because trees purify the Air. Land pollution , air pollution , water pollution may increase. Biodiversity can be affected.
The right answer is A. lens
The eye-lens is a natural convergent lens of the eye.
The eye has two natural convergent lenses: the cornea, located at the entrance of the eye, and the crystalline, biconvex lens located behind the iris and connected to the envelopes of the eye by the ciliary body. These two lenses focus the light rays on the retina, which acts as a screen in the back of the eye.
Answer: Option D) All living things are made up of cells
Explanation:
The cell theory states that:
- the cell is the structural and functional unit of life
- all living organisms are made of cells
- all cells come from previously existing cells
- there is no life apart from the life of cells
- all living things are either single cells (unicellular) or group of cells (multicellular)
