What is a stimuli? please give examples?

The changes in the environmental conditions to which the organisms respond are known as stimuli.

For example, living things respond to changes in light, heat, sound, and chemical and mechanical contact.

Explanation:

I hope it'll help you...

A stimulus is anything that can trigger a physical or behavioral changes.

Example:- Of external stimuli is your body responding to a medicine. An example of internal stimuli is your vital signs changing due to a change in the body.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: