Explain the relationship between the environment, variation, and selection. changing can cause certain traits to be favored through . this can lead to changes in .

The relationship between environment, variation and selection lay the foundation for natural selection and evolution.

Genetic variations are present among species due to number of reasons like recombination or crossing over during meiosis, mutations, random fertilization etc. These factors bring changes among the members of a species. Some of the species become better adapted to survive in a particular environment whereas some are not better adapted and become extinct over a period of time. The environment selects the organisms that are best adapted to survive and hence lead to variations.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.