Variations Definition
Structural, functional, or physiological differences between individuals.
Do all variations become adapations?
No, NOT all variations become adaptations.
What determines whether a variable has a positive/negative/no effect on an individuals ability to survive and reproduce? (2 points)
- Individuals possessing a helpful variation are more likely to survive and have a higher chance of passing this variation onto their offspring.
- This will result in variation becoming more frequent, to the point where it becomes a CHARACTERISTIC or TRAIT of the population.
What is an example of variation?
-One example of variation between individuals would be puppies in a litter and kittens in a litter not all looking the same.
Why is there variation in individuals (particularly in the case of puppies in a litter and kittens in a litter)?
They have inherited different parts of the DNA (called Alleles) from their parents.
How is this genetic information expressed in an individual? (2 points)
- Some of this genetic information is expressed in the phenotype of each individual, which includes its physical appearance and behaviour.
- But much of it has no visible effect and remains part of each individual’s genetic make-up and continues to be passed on to next generations.
Genetic Variation Definition
In a population, it results from the variety of genetic information in all individuals of the population.
Mutation Definition
A change in the genetic material (DNA) of an organism.
Mutations are what?…
The only source of new genetic variation when inherited.
What continuously happens in the DNA of all living organisms?
Mutation is continuously happening in the DNA of all living organisms.
How can a Mutation occur?
It can occur spontaneously when DNA is copied.
What can a Mutation be caused by?
It can be caused by ultraviolet radiation (or other environmental agents).
What happens after a Mutation?
-The cell could die.
-The cell could malfunction.
-The cell could multiply more than it should and form a tumour.
In what way can Mutations be harmful?
-Mutations that drastically change the shape or structure of DNA can be harmful to an organism.
Are all Mutations harmful?
No, not all mutations are harmful.
How are Mutations passed on/?
Mutations are only passed on through gametes (sexually reproducing cells), and not somatic cells (which make up most of the cells of your body).
Selective Advantage Definition
A genetic advantage of one organism over its competitors.
What does Selective Advantage cause?
-Selective Advantage causes an organism to be favoured in terms of survival and reproduction.
What is an example of how Selective Advantage causes an organism to be favoured in terms of survival and reproduction?
It helps an organism survive changing environmental conditions and reproduce.
How long does Mutation take?
How long Mutation takes all depends on the organism.
Why does how long Mutation take all depend on the organism? (2 points)
- Those that reproduce quickly and have short generations will be seen to show the passing of traits more quickly (this is why Darwin’s Finches adapted in just a few hundred years and why humans haven’t changed too much in a few thousand years!)
- Insects, bacteria, and viruses are all good examples of organisms that have very short life spans, reproduce and adapt quickly to changing environments
What are the three types of Mutation?
- Beneficial
- Neutral
- Negative
What is a beneficial mutation? (2 points)
- A mutation that has a positive effect on the organism in which it occurs.
-It leads to new versions of proteins that help organisms adapt to changes in their environment.
How does beneficial mutation affect evolution? (2 points)
- Beneficial mutations are essential for evolution to occur.
- They increase an organism’s chances of surviving or reproducing, so they are likely to become more common over time.
