What is named by $ICBN$?

Into how many groups did Theophrastus classify plants based on their habitat?

Practice drawing various animals and plants.

$Nicotiana \ sylvestris$ flowers only during long days and $N. \ tabacum$ flowers only during short days. If raised in the laboratory under different photoperiods,they can be induced to flower at the same time and can be cross-fertilized to produce self-fertile offspring. What is the best reason for considering $N. \ sylvestris$ and $N. \ tabacum$ to be separate species?

$ICBN$ stands for

Living organisms vary in which of the following aspects?