Variation and Evolution

Question 1

What are the types of reproduction?

Answer 1

Sexual reproduction and asexual reproduction

Question 2

What are the traits of sexual reproduction?

Answer 2

Two parents.
Gametes produced with 1/2 of the genetic code each.
Combining gametes at fertilisation produces new offspring.
Genetic variation of offspring, higher survival rate in sudden environmental changes.

Question 3

What are the traits of asexual reproduction?

Answer 3

One parent.
No energy wasted producing gametes or mating.
Lots of offspring quick.
No genetic variation (Clones).

Question 4

Define variation.

Answer 4

Differences between members of the same species.

Question 5

Define genetic factors.

Answer 5

Characteristics caused by genes inherited from parent’s DNA

Question 6

Define enviromental factors.

Answer 6

Characteristics that change due to environment.

Question 7

What is most variation caused by?

Answer 7

Groups of genes, or combinations of genetic and environmental factors.

Question 8

What is continuous variation, and how does it look on a graph?

Answer 8

Infinite possibilities.
Controlled by genes and environmental factors
Graph is bell curve, touching bars.

Question 9

What is discontinuous variation, and how does it look on a graph?

Answer 9

Finite possibilities, fit into discrete groups.
Usually controlled by one gene.
Graph is a histogram.

Question 10

Define mutation

Answer 10

A change in a gene.
Random, rate increased by ionising radiation.
Some are inherited and cause disease.

Question 11

What is cystic fibrosis?

Answer 11

A genetically inherited disease causing thick, sticky mucus that blocks bronchioles in the lungs.

Question 12

How can cystic fibrosis be treated?

Answer 12

Gene therapy.

Question 13

What is gene therapy?

Answer 13

An inhaler is used to get the right gene into lung cells, but it isn’t copied into new cells, so its a treatment, not a cure.

Question 14

What is the basis of evolution?

Answer 14

Inheritable evolution.

Question 15

Who worked on the theory of evolution?

Answer 15

Charles Darwin and Alfred Russel Wallace.

Question 15

Define mutation.

Answer 15

Random changes in genes cause variation in species

Question 16

Define variation.

Answer 16

Small differences within a species make some individuals better adapted to the environment.

Question 17

Define competition

Answer 17

Organisms compete for survival, some may have a gene allowing resistance to a toxin, for example.

Question 18

Define survival of the fittest

Answer 18

Those with advantageous genes have a selective advantage over others.
Can compete between for resources or survival an antibiotic/pesticide/other toxin that kills others of that species.

Question 19

Breeding in terms of evolution

Answer 19

Two organism that survive can breed, passing on advantageous genes to children.

Question 20

What happens if the environment changes too quickly?

Answer 20

Extinction due to changes too quick for adaptation through natural selection.

Question 21

How can natural selection be proved?

Answer 21

Through a model that proves better camouflaged organism have an advantage against predators.

Question 22

How can we model natural selection?

Answer 22

Arrange plain + patterned card on a plain background.
Use forceps as predator + record how many of each it picked in 15 seconds.

Question 23

What does the natural selection model show?

Answer 23

Prey that is easily seen/less camouflaged is at a higher risk of predation.

Question 24

What does predation of less camouflaged organisms mean?

Answer 24

Better camouflaged organisms are able to breed and pass on their genes

Question 25

What are the limitations of the natural selection model?

Answer 25

Prey doesn’t move.
Background flat, not textured.

Question 26

What is the purpose of studying human DNA?

Answer 26

Development of new ways to treat, cure, or prevent disease.