B5.2 Natural Selection and Classification

Question 1

What is evolution?

Answer 1

Evolution is the gradual change of a species over time. The theory goes that life began as unicellular organisms in the sea 3 billion years ago and then evolved.

Question 2

What is natural selection?

Answer 2

Natural selection is a way that organisms evolve. Genetic variation occurs through mutation for some animals in a species. The variants that gain the most advantageous mutations are more adapted to their environment and the ones that aren’t adapted die out. The successful genes are passed on to the offspring and gradually the whole species has the same characteristic

Question 3

What are fossils?

Answer 3

Fossils are animal and plant remains preserved in rocks. The fossils found in different layers are different generations, eg the highest layer is the most recent

Question 4

How do fossils provide evidence for evolution?

Answer 4

• Fossils Show That the simplest organisms are found in the loswerft layer of rock. More complex forms are found in recent rock. This supports the theory of evolution
• Plant fossils appear before animals
• Related organisms have similar anatomy, bone structure and DNA to ancestors
• Rapid change in a species, eg bacterial resistance
• DNA comparison - scientists look at the order of amino acids in a protein. Those that are closely related have similar dna

Question 5

What is classification?

Answer 5

The process of sorting organisms into groups with similar features, evolutionary links and characteristics

Question 6

What are the 7 taxonomic levels?

Answer 6

King prawn curry or fat greasy sausages

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 7

What are the 5 kingdoms?

Answer 7

Plants
Animals
Fungi
Protoctista
Prokaryotes

Question 8

What is natural classification?

Answer 8

Classification based on evolutionary links and common ancestry.

Scientists use DNA sequencing to find these links

Question 9

What are Phylogenie links?

Answer 9

Phylogeny is the study of evolutionary links.

Phylogenie links are found by studying similarities and differences in DNA within a species. The more similar they are, the more closely related they are.

Question 10

What artificial classification?

Answer 10

Artificial classification groups organisms together using visible features. This form is highly inaccurate

Question 11

What further evidence allows links of ancestry to be made?

Answer 11

Similarities of intermediate species’ DNA