The method of growing or producing thousands of plants through tissue culture is called

What is done during the process of hardening?

$A:$ In plant tissue culture,the nutrients in the medium decrease.
$R:$ In this method,the biomass of cells or tissues increases.

Assertion $A$: Growth is faster in suspension culture compared to callus culture.
Reason $R$: Agitating the culture in the medium using a rotary shaker facilitates the mixing of nutrients and gas exchange.

In which method is a group of cells suspended in a liquid medium?

Which method is used to develop new plant species in botanical gardens?