Biodiversity over time

Question 1

What is extinction and how is it caused

Answer 1

When a species no longer exists therefore the alleles for the species have been eradicated.

• A change in the environment so rapid that the course evolution couldn’t occur
• small interbreeding populations with little variation suffer the adverse effects of a changed selection pressures
• action of humans

Question 2

The idea of evolution

Answer 2

is based on the theory that populations of organisms go thru periods of change over long periods of time

Question 3

different between micro and macro evolution

and what does macro include

Answer 3

micro - small scale changes within gene pools over generations
macro - its the term used to describe large scale changes in form as viewed in the fossil record , involving whole groups of species and generations

includes adaptive radiation of groups of species into diff environments
evolutionary novelties - wings and feathers

Question 4

Evidence for evolution

Answer 4

palaeontology
Embryology 
compartive anatomy
biogeography 
artificial slectuon 
biochemistry
molecular genetics

Question 5

Steps to fossil formation

Answer 5

1- dead remains of organism may fall into lake or sea and become buried in silt/sand in low temp condition ( anaerobic )
2- HARD PARTS of Skelton may persist and become impreganted
3- remains hardened in this way become compressed
4-

Question 6

Interpretaion of rock layers containing fossils

Answer 6

allows us to arrange the fossils in chronological order but doesn’t give their absolute date

Question 7

radioisotopic dating what is it

Whats the process

Answer 7

is a method to calculate the absolute age of fossils.

Its the process based on the idea that naturally occurring isotopes will breakdown (decay ) at a known rate.

Question 8

Breaking down at a known rate is …..

Answer 8

isotopic half life

Question 9

In livening organsims their is both C12 and C14 what happen when organism dies
how many years does it take

Answer 9

C12 stays the same , however C14 changes to Nitrogen

5730

Question 10

what is geological time scale

Answer 10

fossile and the dating of evidence and dating fossils brings about the possibility to put all fossils in an order of time

Question 11

Homologus structures

Answer 11

Structure in diff organism that have similar base pattern , thru common evolutionary origin.Even tho they may serve a diff function

Question 12

Analogus structures

Answer 12

Not all similarities between species are inherited from common ancestors.They may indicate convergence

Question 13

Convergence

Answer 13

the tendency of unrelated animals and plants to evolve superficially conditions

Question 14

Vestigal structures

Answer 14

Many transitional fossils have structures that are no longer used.EG the reduced hip + leg bones found in modern whales

Question 15

DNA hybridization
how does it occur
what is it
how is work

Answer 15

DNA is isolated from blood samples from each species
The greater the attracration the. stronger the two strands are to seperate
DNA from other species is unzipped and recombined to form hybrid DNA
- heat can be used to seperate the hyridzied strands

Question 16

Whats the effect of the amount of heat used on DNA hybridisation

Answer 16

the amount of heat required to seperate is a manger of how similar the 2 DNA strands are ( % bonding )

Question 17

Amino Acid sequencing

- Closely related

Answer 17

• have proteins with similar amino acid seq

- The degree of sim of these proteins is determine by the no. of mutations that have occurred

Question 18

Divergent

Answer 18

An interbreeding population or species separates into 2 or more descendant species resulting in similar species becoming more and more dissimilar