Question

Refer to the given dichotomous key.
I. (a) Fibre obtained from natural resources - Go to II
(b) Fibre obtained from chemicals - P
II. (a) Plant fibre - Go to III
(b) Animal fibre - Go to IV
III. (a) Fibre obtained from seeds of plants - Q
(b) Fibre obtained from stem of plants - R
IV. (a) Fibre obtained from mammal - S
(b) Fibre obtained from insect - T
Which of the following is incorrect regarding $P,Q,R,S$ and $T$?

• A. $P$ is a petroleum based fibre which does not absorb water readily
• B. Both fibres $Q$ and $S$ are obtained from their source organisms without harming them
• C. $Q$ is separated from seeds by retting whereas $R$ is separated from stems by ginning
• D. $S$ can be obtained from the same animal again and again whereas $T$ can be obtained from an animal only once in its lifetime

Answer 1

The correct option is C $Q$ is separated from seeds by retting whereas $R$ is separated from stems by ginning

In the given dichotomous key $P,Q,R,S$ and $T$ represent synthetic fibres (rayon, nylon, polyester), cotton, jute or flax, wool and silk respectively. Cotton $\left(Q\right)$ is separated from seeds by ginning while jute $\left(R\right)$ is separated from stems by retting.