B2.8 Speciation Flashcards Preview

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Flashcards in B2.8 Speciation Deck (15)
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1
Q

State speciation

A

Speciation - new species develop

2
Q

Define a fossil

A

The preserved remains of organisms

3
Q

Define extinction

A

The permanent loss of all members of a species

4
Q

Define endangered

A

When the species is near extinction

5
Q

What are the reasons for extinction

A
Introduction of NEW diseases
Introduction of NEW competitors
Introduction of NEW predators
Lack of nutrients
Environmental change
6
Q

How are fossils made?

A

Ice
Amber
Sedimentation
pH conditions

7
Q

Define species

A

A group of similar organisms that can interbreed

8
Q

What is speciation?

A
Separation
Genetic variation
Natural selection 
Alleles passed on
Species can no longer interbreed
9
Q

What are the limitations of the fossil record?

A

Early organisms were soft-bodied
Fossils can get damaged e.g. by geological activity
There are often gaps in fossil records

10
Q

How can fossils give evidence for evolution?

A

Fossils show change over time

11
Q

Why are scientists not sure of what the skin of extinct organisms were like?

A

The skin decays

12
Q

What can we learn by studying fossils?

A

Evolution
The age of the fossil
Habitats

13
Q

When answering a 4 mark question for speciation what are your four steps?

A
  1. State how species can be geographically isolated.
  2. Describe what is meant by variation + explain what it’s caused by.
  3. Describe what natural selection is.
  4. Describe what is meant by speciation.
14
Q

Define natural selection

A

Natural selection - when a organism adapts to an environment better than another organism

15
Q

Define genetic variation

A

A difference in a gene.