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

Evolution

QuestionAnswer
What is evolution? The changes in organisms over generations as a result of genomic variations.
What is natural selection? The non-random increase in frequency of DNA sequences that increase survival and the non-random reduction in the frequency of deleterious sequences.
Which three types of selection can result in a change of phenotype frequency? Stabilising, directional and disruptive selection.
What are the effects of stabilising selection? An average phenotype is selected for and extremes of the phenotype range are selected against.
What are the effects of directional selection? one extreme of the phenotype range is selected for.
What are the effects of disruptive selection? two or more phenotypes are selected for.
What is horizontal gene transfer? When genes are transferred between individuals in the same generation.
What is vertical gene transfer? When genes are transferred from parent to offspring as a result of sexual or asexual reproduction.
Why can prokaryotes evolve quicker than eukaryotes? Because they can transfer genetic material horizontally.
What is speciation? The generation of new biological species by evolution as a result of isolation, mutation and selection.
What is a species? A group of organisms capable of interbreeding and producing fertile offspring, and which does not normally breed with other groups.
What is the significance of isolating barriers? They prevent gene flow between sub-populations during speciation.
What are the three types of isolating barriers? Geographical, ecological, behavioural.
What is allopatric speciation? Speciation which occurs as a result of a geographical barrier.
What is sympatric speciation? Speciation which occurs as a result of a behavioural or ecological barrier.
Summarise the events in speciation. Isolating barrier, mutations, natural selection, many generations, two new species formed
Created by: MISSCBIO
Popular Biology 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