The diagram shows a process used in agriculture - HSC - SSCE Biology - Question 34 - 2016 - Paper 1

1. This area occurs because the cloning process ensures that only chromosomes from the donor organism are present, resulting in genetically identical offspring.
2. It provides for the maintenance of specific desirable traits by ensuring that the offspring stay true to the genetic makeup of the parent.

Selective breeding is the process of choosing specific parents with desirable traits to breed with one another. Over generations, this practice leads to a population that exhibits these chosen traits more prominently. For example, consider modern agro-crops like wheat. Farmers select for high yield and disease resistance, allowing those traits to become prevalent within the population. This, in turn, increases productivity and sustainability, as the newly bred varieties can outcompete pests and adapt better to the growing conditions compared to their predecessors.

In humans, the ABO blood group system exemplifies multiple allelism with three alleles: A, B, and O. In Drosophila (fruit flies), multiple alleles controlling traits such as eye color include several variations, resulting in a range of eye colors from red to white.

A suitable sketch would display a bell-shaped curve illustrating the variation in height within a human population. The x-axis represents height in centimeters, while the y-axis shows the number of individuals. This graph demonstrates continuous variation, characteristic of polygenic traits, indicating that height results from the combined effect of multiple genes.