Explain how a sudden and drastic envi- ronmental change might lead to the
extinction of a species.

Name the plastid and pigment likely to be found in the cells of (a) petals of sunflower (b) ripe tomato.

What is the main difference between the central nervous system (cns) and the peripheral nervous system (pns)? .the cns involves the brain and spinal cord, and the pns involves the body nerves. the cns involves the body nerves, and the pns involves the brain and spinal cord. the cns involves sensory neurons, and the pns involves motor neurons. the cns involves motor neurons, and the pns involves sensory neurons.

Which of the following explains why a tree is often used as a model to represent the principle of common descent