Classification UNIT 2

Question 0

What is involved in taxonomy

Answer 0

Naming and organising organisms into similar groups based on their similarities and differences

Question 1

What is taxonomy

Answer 1

The science of classification

Question 2

Why do scientists classify organisms

Answer 2

To make it easier to identify and study them

Question 3

7 taxonomic stages….

Answer 3

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 4

As you move down the taxonomic groups there are…..

Answer 4

More groups but fewer organisms in each group

Question 5

What is a species

Answer 5

A group of similar organisms able to reproduce to give fertile offspring

Question 6

How are species named

Answer 6

A two-word name in Latin

First word…genus ALWAYS BEGINS WITH A CAPITAL
Second word….species

Question 7

Phylogenetics

Answer 7

Is the study of the evolutionary history of groups of organisms

Question 8

Species can also be classified by….

Answer 8

Comparing their DNA sequence or by looking at their proteins

Question 9

Organisms that are MORE CLOSELY related will have …… ………… DNA and proteins than distantly related organisms

Answer 9

More similar

Question 10

DNA similarity can be measured by looking at……

Answer 10

DNA sequencing or by DNA hybridisation

Question 11

Info on DNA sequencing

Answer 11

The DNA can be directly compared by looking at the order of the bases. Closely related species will have a higher percentage of similarity in their DNA base order .

Question 12

Info on DNA hybridisation

Answer 12

Used to see how similar DNA is without sequencing it.

DNA from 2 different species collected, separated into single strands and mixed together
Where the base sequences of DNA are same on both strands, hydrogen bonds form by specific base pairing. The more bases that hybridise, the more alike the DNA
DNA heated to separate strands. Similar DNA will have more hydrogen bonds holding 2 strands together so higher temp need to separate them

Question 13

2 ways of comparing proteins

Answer 13

Comparing amino acid sequence or immunological comparisons

Question 14

Info on comparing amino acid sequence

Answer 14

The sequence of amino acids in a protein are coded for by the base sequence in DNA. Related organisms have similar DNA sequences and so have similar amino acid sequences in their proteins

Question 15

Info on immunological comparisons

Answer 15

• protiens in serum act as antigens
• inject these antigens into an animal and it will produce antibodys
• these antibodys are extracted and put into a separate sera
• the original animal will have 100% precipitate
• the higher the % precipitate the more closely related the animals are

Question 16

What is meant by a heirarchy

Answer 16

Groups within groups, no overlapping

Question 17

Comparing the base sequence of genes provides more evolutionary info than comparing the structure of proteins. Explain why?

Answer 17

3 bases code for each amino acid so the base sequence is longer than the amino acid sequence. It may also contain introns which makes it even longer. The degenerate nature of the DNA means that one triplet can code for more than one amino acid