Biology- Variation and selection

  • Created by: Kitsune
  • Created on: 05-03-17 03:11
What is variation?
The difference between individuals of the same species
1 of 33
What two types of variation are there?
Continuous and discontinuous
2 of 33
Describe continuous variation
Characteristic has a range, quantitive, is affected by genes and environment
3 of 33
Give examples of continuous variation
Height, body mass
4 of 33
Describe discontinuous variation
You either have it or not, cannot be a measured, result of genes only
5 of 33
Give examples of discontinuous variation
blood group, gender
6 of 33
Give examples of both continuous and discontinuous variation.
Hair and eye color
7 of 33
What 3 things can cause mutation?
Uneven distribution of chromosomes during division, damage to DNA, mistake in copying DNA
8 of 33
What is gene mutation?
A change in the base sequence of DNA
9 of 33
What are the symptoms of sickle cell anaemia?
Weakness, poor blood circulation, aching joints
10 of 33
What gene is mutated in sickle cell anaemia?
11 of 33
How is faulty hemoglobin made?
Faulty mRNA is made because the hemoglobin gene is mutated
12 of 33
Mutation is the way in which new....
alleles are formed
13 of 33
What are factors of mutation called?
14 of 33
What increases the rate of mutation?
Ionising radiation and some chemicals
15 of 33
What is cancer?
Uncontrollable cell division
16 of 33
What are the mutagens that cause cancer called?
17 of 33
What are adaptive features?
Inherited functional features of an organism that increase its fitness
18 of 33
What is fitness?
Probability that an organism will survive and reproduce in its environment
19 of 33
What is the result of more successful individuals breeding?
Their alleles will be passed in to successive generations
20 of 33
What is evolution?
A change in adaptive features of a population over time as a result of natural selection
21 of 33
What is selection pressure?
When food resources become available only to some so only those with adaptation features survive
22 of 33
What is the process of adaptation?
Process, resulting from natural selection, by which populations become more suited to their environment over many years
23 of 33
What is artificial selection?
Selecting those individuals that have the most useful characteristics and allowing only these individuals to breed
24 of 33
What is another name for artificial selection?
Selective breeding
25 of 33
Describe artificial insemination.
Desired males are stimulated to ejaculate. Their sperm is collect and frozen. It is taken to many farms to inseminate females
26 of 33
Describe plant breeding.
Pollen is transferred form stamen of one flower to the stigma of another and after a plant with desirable characteristics is obtained it is multiplied by asexual reproduction.
27 of 33
Who are the agents of selection in artificial selection? Natural selection?
Humans. Environment
28 of 33
Is artificial selection after than natural?
29 of 33
Artificial selection ........ to an organism in its natural environment
offers no advantage
30 of 33
By what process are strains of antibiotic resistant bacteria formed?
Artificial selection
31 of 33
Describe how a whole population of bacteria can become resistant
Mutation results in one resistant cell in the population. This cell survives and reproduces, giving rise to a resistant population.
32 of 33
How can development of resistant bacteria be minimized?
By using antibiotics only when essential and ensuring complete treatment
33 of 33

Other cards in this set

Card 2


What two types of variation are there?


Continuous and discontinuous

Card 3


Describe continuous variation


Preview of the front of card 3

Card 4


Give examples of continuous variation


Preview of the front of card 4

Card 5


Describe discontinuous variation


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Variation and selection resources »