Save
Busy. Please wait.
Log in with Clever
or
show password
Forgot Password?
Don't have an account?  Sign up 
Sign up using Clever
or
Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account. Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't Know
Remaining cards (0)
Know
0:00
edit
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

changes in the gene

as part of 91157

TermDefinition
Allele frequency The proportion of an allele in the gene pool. Calculated as: number of that allele รท total number of all alleles for that gene in the gene pool.
population bottleneck A population is suddenly reduced due to a catastrophic event to a few individuals and then recovers with low genetic diversity.
Founder effect A new population is established by a small number of individuals from an existing (ancestral) population, with lower genetic diversity.
Genetic variation The range of all the alleles in a population; the greater the number of different alleles present, the greater this is.
genetic drift The change in allele frequencies in populations due to chance events (not selection). It may include the loss of alleles from a gene pool. The effects are greatest in small populations.
Natural selection Phenotypes which are best suited to the environment have the greatest reproductive success. This changes the allele frequencies in the gene pool.
selection pressure Anything that affects the survival and reproductive success of an individual
artificial selection When humans select for alleles that are favourable to them and not necessarily the organism. This can artificially alter the alleles frequency in the gene pool and can reduce the ability of the organism to survive in nature.
Disruptive selection Occurs in a population when phenotypes at the extremes have higher fitness than intermediate phenotypes.
Directional selection Occurs in a population when intermediate and phenotypes at one extreme have higher fitness than phenotype at the other extreme.
Stabilising selection Occurs in a population when intermediate phenotypes have higher fitness than phenotypes at the either extreme.
Immigration Individuals coming into the gene pool. Increases allele frequency and can introduce new alleles.
Emmigration Individuals leaving the gene pool. decreases allele frequency and can reduce genetic diversity.
Created by: NZARoberts
Popular Genetics sets

 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
Retries:
restart all cards