4.2.2: Classification And Evolution

Question 1

What is the term for differences between members of different species?

Answer 1

Interspecific variation

Interspecific variation is the widest type of variation and can include differences in feeding mechanisms, number of legs, and fur or hair.

Question 2

What is the term for differences between members of the same species?

Answer 2

Intraspecific variation

Intraspecific variation occurs despite members of the same species having the same genes, due to different versions (alleles) resulting from genetic variation.

Question 3

What introduces genetic variation within the same species?

Answer 3

• Mutations
• Crossing over
• Independent assortment in meiosis
• Sexual reproduction
• Random fertilisation

These processes contribute to the genetic diversity observed within a species.

Question 4

How does the environment impact variation in plants compared to animals?

Answer 4

Environmental factors have a greater impact on plants because they cannot move and are always exposed to environmental conditions

Conditions include precipitation, wind, sunlight, and soil nutrients.

Question 5

What are some examples of variation in humans created solely by environmental factors?

Answer 5

• Tattoos
• Piercings
• Scars

These examples illustrate how environmental factors can lead to variation in individuals.

Question 6

What is continuous variation?

Answer 6

Traits controlled by many genes where the environment can have an impact

Continuous variation is graphically represented using a histogram.

Question 7

What is discontinuous variation?

Answer 7

Traits controlled by a single gene with no environmental impact

Discontinuous variation results in individuals fitting into particular categories and is represented with a bar chart.