Altitude sickness is an example of:

Phenotypic variants formed in a population due to change in environment are called

Which of the following areas are used as habitats by organisms?
$I -$ Scorching deserts
$II -$ Rain-soaked rainforests
$III -$ Rushing streams
$IV -$ Deep ocean trenches
$V -$ Polar regions
$VI -$ High mountain tops
$VII -$ Thermal springs
$VIII -$ Stinking compost pits
$IX -$ Our intestine

$Niche$ is:

When an organism moves away temporarily from a stressful habitat to a more hospitable area and returns when the stressful period is over,what is this process called?

$A$ person moves from Delhi to Shimla during the hot summer days. This is an example of which of the following?