Biology revision-Genetic Diversity

What is genetic diversity?
The differences in DNA/ base sequences between individuals within a population
1 of 21
What is allele frequency?
How often a particular allele occurs in a population
2 of 21
How can genetic diversity be increased?
Meiosis: Crossing over/ Independent assortment of chromosomes in metaphase 1 and chromatids in metaphase 2 of meiosis/ Genetic mutations/ Outbreeding
3 of 21
How can genetic diversity be decreased?
Selective breeding- Artificial selection/ Founder effect/ Genetic bottleneck
4 of 21
What is selective breeding/ Artificial selection?
It involves identifying individuals with the desired characteristics and using them to parent the next generation. Offspring that do not exhibit the desired characteristics are killed, or at least prevented from breeding. unwanted alleles are killed.
5 of 21
What is genetic bottlenecks?
When populations of a species suffer a dramatic drop in numbers. The few survivors will possess a much smaller variety of alleles than the original population. e.g the northern elephant seals now are less diverse as they have fewer alleles.
6 of 21
What are the advantages of genetic variation?
Genetic diversity is important in a species for the long term survival of that species, as the greater the genetic diversity, the more likely that the species is able to adapt and to survive changes in the environment.
7 of 21
What is a mutation?
A mutation is a change in the DNA.
8 of 21
What are mutations caused by?
- Natural copying errors (during DNA replication - Mutagens
9 of 21
What is a gene or point mutation?
A change in the base sequence of a gene, which can cause a change in the polypeptide chain. It is caused by errors that occur during DNA replication
10 of 21
What is a chromosome mutation?
A change in the number or structure of the chromosomes. It is caused by errors that occur during cell division
11 of 21
What is cancer?
Cancer is a group of diseases characterized by uncontrolled cell division leading to growth of abnormal tissue
12 of 21
What 2 genes control the rate of cell division?
proto-oncogene- stimulates cell division/ Tumour suppressor gene- slows or inhibits cell division
13 of 21
State 3 reasons why mitosis is important to organisms?
1. Growth 2. Repair 3. Asexual reproduction
14 of 21
What is the role of chiasmata?
Hold homologous chromosomes together as a bivalent/ Separate alleles on same chromosome- increased genetic variation in gametes
15 of 21
What is meant by bivalent?
Bivalent is a pair of homologous chromosomes
16 of 21
What is meant by a chromatid?
A chromatid is each of the 2 thread like strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.
17 of 21
What is a centromere?
The region of a chromosome to which the microtubules of the spindle attach. via the kinetochore, during cell division
18 of 21
What is chiasmata?
The point where 2 homologous non sister chromatids exchange genetic material during chromosomal crossover in meiosis
19 of 21
What are homologous chromosomes?
The cell has 2 sets of each chromosome; one of the pair is derived from the mother and the other from the father. The maternal and paternal chromosomes in a homologous pair have the same genes at the same loci, but possibly different alleles.
20 of 21
What is cytokinesis?
Cytokinesis is the physical process of cell division, which divides the cytoplasm of a parental cell into 2 daughter cells. It occurs concurrently with 2 types of nuclear division called mitosis and meiosis, which occur in animal cells
21 of 21

Other cards in this set

Card 2

Front

What is allele frequency?

Back

How often a particular allele occurs in a population

Card 3

Front

How can genetic diversity be increased?

Back

Preview of the front of card 3

Card 4

Front

How can genetic diversity be decreased?

Back

Preview of the front of card 4

Card 5

Front

What is selective breeding/ Artificial selection?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Genetic Diversity resources »