Variation: แบบฝึกหัด

A group of students measured the height of 100 pea plants grown from seeds of the same parent plant. They found that the heights ranged from 15 cm to 45 cm, with plants at every height in between.
Which of the following statements correctly identifies the type of variation and its cause?

Differences in the characteristics of individuals of the same kind can be due to various causes. According to the syllabus, which of the following best explains the origin of genetic variation within a population?

In a population of rabbits, most individuals have brown fur, but a small number are born with white fur due to a mutation in a single gene.
Which process is most likely to lead to a change in the proportion of white-furred rabbits in the population over many generations?

Differences in the characteristics of individuals of the same kind can be caused by genes, the environment, or both. Which of the following describes variation caused solely by genetic factors?

A scientist collects data on the blood groups (A, B, AB, and O) of a population and displays the results in a bar chart. Which type of variation is shown by this data?

What is meant by environmental variation in organisms?

State two distinct causes of genetic variation within a population of the same species.

Explain the steps by which geographical isolation leads to speciation, and state the criteria used to determine when two populations have officially become separate species.

The characteristics of an individual can be influenced by their genes, their environment, or a combination of both.
a) Define environmental variation and provide one specific example of this in a species of plant.
b) Explain how genetic factors and environmental factors (such as diet or disease) might interact to determine the final adult height of a human.
c) Classify 'blood group' as either continuous or discontinuous variation and justify your choice by describing the typical distribution of such a trait.