Question

(a) Scientists record the mass of each baby at birth in one country.
The results are shown in Fig. 10.1

(i) Complete the sentences about the mass of babies at birth as shown in Fig. 10.1.
The lowest mass at birth was ……………………………………….. g.
The most frequent mass at birth was ……………………………………….. g.
Fig. 10.1 shows that mass of babies at birth is an example of continuous variation.
This is because there is a ……………………………………….. of phenotypes between two extremes.
A phenotype is defined as the ……………………………………….. features of an organism.
(ii) State one other example of continuous variation in humans.

(b) The statements A–E describe stages of natural selection.
They are not in the correct order.
A   There is competition for resources.
B   Those with adaptations best suited to their environment survive and reproduce.
C   This process is repeated over several generations.
D   There is variation in a population.
E   Alleles are passed on to the next generation.
Complete the answer spaces to show the correct order.
One has been done for you.

(c) Alleles are made of DNA.
(i) Define the term allele.
(ii) State where alleles are found in a cell.