Evolution, fossils, speciation & classification

Question 1

What is the theory of evolution

Answer 1

All of todays species have evolved from simple life forms that first started to develop over 3 billion years ago

Question 2

What are the 4 steps of natural selection

Answer 2

1. All of the individuals in a species show a wide range of variation for a particular characteristic
2. Because of this range in variation, some of these individuals are better suited to the environment than others.
3. The individuals who are most suited to the environment are more likely to survive, and therefore more likely to breed successfully.
4. The useful characteristicwill be passed onto the offspring.

Question 3

How have scientists developed the theory of evolution and what are the 3 steps

Answer 3

1. Individuals within a species show wide variation in thir characteristics because of the mix of genetic variants present in the population.
2. Some genetic variants give rise to characteristics that are better suited to the environment. Organisms with these characteristics have a better chance of survival and so are more likely to breed succesfully.
3. So, the genetic variants that are responsible for the useful characteristics are more likely to be passed onto the next generation.

Question 4

What is speciation

Answer 4

Over a long period of time, the phenotype of organisms can change so much because of natural selection that a completely new species is formed.

Question 5

when does speciation happen

Answer 5

when populations of the same species change enough to become reproductively isolated, meaning that they can no longer reproduce succesfully and produce fertile offspring.

Question 6

3 reasons extinction can occur

Answer 6

Environment changes too quickly
A new disease kills them all
Cant compete with another species for food.

Question 7

What are fossils

Answer 7

Remains of organisms from many years ago which are found in rocks

Question 8

What 3 ways can fossils form

Answer 8

From gradual replacement by minerals
From casts and impressions
From preservation in places where no decay happens.

Question 9

Whats isolation

Answer 9

where populations of a species are seperated, this can happen due to a physical barrier

Question 10

How does natural selection occur when species are isolated

Answer 10

Each population shows genetic variation because they have a wide range of alleles.

In each population, individuals with characteristics that make them better adapted to their environment have a better chance of survival and so are more likely to breed successfully.

So the alleles that control the beneficial characteristics are more likely to be passed onto the next generation

Question 11

What are the 7 groups in the linnaean system

Answer 11

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 12

What are the members of the three domain system

Answer 12

Archea
Bacteria
Eukaryota

Question 13

What organisms are in the eukaryota

Answer 13

fungi
plants
animals
protists

Question 14

What organisms are in bacteria

Answer 14

E. coli
Staphylococcus

Question 15

Where can archaea be found

Answer 15

In hot springs and salt lakes.