9.2 Evidence Use In Classification

Question 0

Anatomical:

Answer 0

Classification related to the anatomy and structure and function of organisms and their parts

Question 1

Biochemical:

Answer 1

Characterised by, produced by or involving chemical reactions in living organisms - usually DNA and proteins are compared

Question 2

Embryological:

Answer 2

Classification related to embryo development

Question 3

Immunological:

Answer 3

Classification related to the body’s natural defences or immunity against disease (immune response)

Question 4

Behavioural:

Answer 4

Classification related to behavioural interactions

Question 5

How does biochemical evidence help in classification:

Answer 5

• Enables scientists to confirm phylogenies and disprove others
• Can date each split in the lineage
• DNA-DNA hybridisation compares the total genomes of different species (measuring the degree of genetic similarity - determines genetic distance, more similarity in genomes=less time for mutation)
• Protein sequencing establishes homologies
• Amount of molecular change a protein shows can be used as a molecular clock to date evolutionary events

Question 6

Example of biochemical =

Answer 6

Sequence homologous of cytochrome c used to construct a phylogenetic tree for species across a wide range of taxa

Question 7

How does anatomical help in classification?

Answer 7

• Determine relationships between organisms based on overall degree of similarity or by tracing the appearance of key characteristics
• Homologies suggest that they all descended from a common ancestor with that feature

Question 8

Examples of anatomical:

Answer 8

-Bones of the forelimb of air-breathing vertebrates are composed of similar bones arranged in a comparable pattern - common ancestry

Question 9

How does embryological help in the classification?

Answer 9

-Early embryos look very similar; it is only in the later stages of development that the embryos look different - evolved from a common ancestor

Question 10

Example of embryological:

Answer 10

All vertebrate embryos have a tail-like structure early in their development, but only some of them have a tail in the later stages