Types of variation 10.5

Question 1

What are variations

Answer 1

The differences in characteristics between organisms

Question 2

What is interspecific variation

Answer 2

The variation that occurs between members of different species

for example a mouse has 4 legs, teeth and fur whereas a bird has 2 legs, a beak and feathers

Question 3

what is infraspecific variation

Answer 3

Differences between organisms within a species

For example, people vary in height, build, hair colour and intelligence

Question 4

what are the 2 factors that cause variation

Answer 4

• an organisms genetic material-differences in the genetic material an organism inherits from its parent leads to genetic variation
• the environment in which the organism lives-this causes environmental variation

Question 5

How can alleles cause genetic variation

Answer 5

• Genes have different alleles (alternative forms).
• different alleles produce different characteristics
• Individuals in a species inherit different alleles of a gene creating genetic variation

Question 6

How can mutation cause genetic variation

Answer 6

• changes to DNA sequence can result in new genes and therefore proteins
  ^can affect features of organism
• if mutation in somatic (body) cells just individual affected
• if occurs in gametes mutation may be passed on to offspring
• Both can result in variation

Question 7

How can meiosis cause variation

Answer 7

Gametes (sex cells) are produced by the processes of meiosis in organisms that reproduced sexually.
Each gamete receives half the genetic content of a parent cell.
Before the nucleus divides and chromatids of a chromosome separate, the genetic material inherited from the 2 parents is ‘mixed up’ by independent assortment and crossing over.
This leads to the gametes of an individual showing variation.

Question 8

How can sexual reproduction cause genetic variation

Answer 8

The offspring produced from 2 individuals inherits genes (alleles) from each of the parent. Each individual produced therefore different from the parent

Question 9

How can chance cause genetic variation

Answer 9

Many different gametes are produced from the paternal genome.
During sexual reproduction it is a result of chance as to which 2 combine (often referred to as random fertilisation).
The individuals produced therefore also differ from their siblings as each contains a unique combination of genetic material

Question 10

what is produced from asexual reproduction and how can genetic variation arise in these

Answer 10

• clones (individuals that are genetically identical to their parents) are produced
• Genetic variation can only be increased in these organisms as a result of mutation

Question 11

How can the environment create variation

Answer 11

All organisms are effected by their environment, Plants may be more affected to a greater degree than animals due to their lack of mobility

For example, 2 rose bushes are planted in different positions in a garden. The one that has greater access to the sun will generally grow larger than one in a shadier position

scars are also an example of environmental variation