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

Chp18Variation+Evo

QuestionAnswer
variation means that there are differences between the members of a species
mutation a change in the amount of structure of DNA
mutagen a mutation causing agent
gene mutations aka point mutation: changes in a single gene
chromosome mutations a large change in the structure or number of one or more organisms
evolution the way in which organisms change genetically to produce new forms of life over long periods of time
natural selection the process by which those organisms with the genetically controlled characteristics that allow them to be well adapted to their environments will survive to pass on their genes to the following generations
causes of variation sexual reproduction and mutations
why are mutations rare? 1 because cells contain enzymes that repair damaged DNA 2 the dominant allele on the second homologous chromosome still works
causes of mutations mutagens and spontaneous mutations
spontaneous mutation when DNA doesnt produce exact copies of itself / fails to repair properly
Mutagens Tobacco smoke , ionizing radiation - xrays and gamma rays, dioxins
Sickle Cell anemia - what happens? 1haemoglobin produced with incorrect amino acid 2forming insoluble haemoglobin 3causing sickle shape RBC 4which clumps the blood 5leading to paleness weakness pain and heart failure
Down's Syndrome Caused by the presence of an extra chromosome 21- happens when the egg gamete has two copies and the sperm adds another Causes a range of physical and mental features
Why is there a struggle for existence? Over-breeding and constant population numbers
Evidence for evolution the study of fossils- paelaeontology
What does the study of fossils reveal? 1 Fossils can be aged and compared to a time scale 2Fossils discovered can how changes when compared to modern organisms 3More modern fossils show increased complexity 4Fossils evidence can be linked to environmental change
Created by: serrraphina
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