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Flashcards in 8.1 Deck (15):
1

3 factors needed for a population of organisms to evolve are:

Variation
Heredity
Means of selection

2

What is meant by variation?

there must be differences between the individuals in a population

3

What is meant by heredity?

The differences between organisms must be heritable

4

What is meant by means of selection?

must be a mechanism or pressure that selects some variables for the next generation at the expense of others

5

Genotype is?

The genetic composition of an organism

6

What 2 factors can both determine phenotype?

Genotype
Environment

7

2 causes of genetic variation?

Mutation
Sexual recombination

8

4 factors of mutation for genetic variation:

-Deletion, addition or substitution of nucleotides
-Deletion or translocation of part of a chromosome
-Aneuploidy- loss or gain of whole chromosome set
-Polyploidy - the addition of whole chromosome set

9

What are the 3 factors for sexual recombination in genetic variation:

-Independent assortment of chromosomes (metaphase) in meiosis
-Crossing over during meiosis (prophase)
-Random fertilisation

10

What are the 3 factors for environmental variation:

-Organisms can be affected by the environment
-Food availability
-Can evolve to be flexible to environment

11

In certain environments, individuals that may inherit a mutant allele may be at a selective advantage as they are:

more likely to survive and produce offspring that also carry the mutant allele, this leads to an increase in the frequency of the mutant allele in the population (increasing allele frequency) - population is evolving

12

Gene pool is defined as:

All the genetic information present within a population at a given time

13

Gene pool composition changes from one generation to the next as the...

relative proportions of alleles vary

14

(Gene pool) if there is a consistent change in allele frequency then a population is...

evolving

15

Allele frequency is:

The number or times an allele occurs within the gene pool