• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

Card Range To Study



Play button


Play button




Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

29 Cards in this Set

  • Front
  • Back
A method, used by biologists, that reflects on an evolutionary history, grouping closely related organisms together...
Phylogenetic method
On a phylogenetic tree if organisms are grouped closely or have many similar characteristics, this shows they have...
A common recent ancestor.
What is classification?
The placing of organisms into groups.
What is a hierarchy?
A system of ranking in which small groups are nested components of larger groups.

Hierarchy of Biological classification from largest taxon to smallest.

(Do Keep Ponds Clean Or Fish Get Sick)









Why do we need a classification system.

- If a new animal is discovered, we can predict some of it's other characteristics, based on our general understanding of other animals.

- When we communicate it is quicker to say 'bird' instead' listing all its characteristics.

- A phylogenetic classification system allows

us to infer evolutionary relationships. ( if 2 organisms in the same taxon, we can infer they are closely related).

- More useful to count families rather than species when describing the health of an ecosystem or rate of extinction.

What are the 3 domains in the 3 Domain System?

Domains defined on similarities in DNA base sequence.

1. Eubacteria

- Prokaryotes (E.coli & Salmonella)

2. Archaea

- Bacteria with unusual metabolism (also a prokaryote).

-Live in marine habitats.

-Have a cell wall (no chitin & no cellulose - sometime peptidoglycan).

3. Eukaryota

- All eukaryotic cells containing a membrane bound nucleus.

What are the 5 Kingdoms?

1. Prokaryota

- Unicellular

- All bacteria & cyanobacteria (blue-green algae).

- No membrane-bound organelles.

- Saprophytic, parasitic or autotrophic.

2. Protoctista

- Unicellular

- Has a nucleus

-Some form colonies of identical cells.

-Amoeba have animal like cells while Euglena have cells like plants and animals.

- Heterotrophic

3. Fungi

- Yeast are unicellular.

- Moulds & mushrooms are multicellular.

- have hyphae that weave together to form the body of the fungus.

- Septa sub-divide the hyphae.

-Heterotrophic & Saprophytic

4. Animalia

- 35 animal phyla

- Show nervous co-ordination

- Most are motile at some stage of their life.

- Heterotrophic

5. Plantae

- Simple reproduce with spores (mosses & ferns).

- Complex reproduce with gametes ( flowering plants & conifers).

- Autotrophic.

What does heterotrophic mean?
Eats other organisms

What does autotrophic mean?

Produces its own food.

What does saprophytic mean?
Secretes enzymes which digest the food outside the cell which then get reabsorbed.

What is a phylum?

A sub-group of a kingdom.

- Members of each phylum have a distinct body plan, e.g

Annelida - soft bodies & segmented

Arthropoda - chitinous exoskeleton & jointed limbs

Chordata - contains the vertebrates

What is a class?

A sub-group of a phylum.

E.g Mammalia - in Animalia

insecta - in Arthropoda

What is a order?

Sub-group of class

E.g Lepidoptera containing butterflies in the class insecta

What is a family?

A group within an order.

E.g rose family Rosaceae

What is a genus?
A group of similar organisms such as the genus Panthera containing lions & tigers.
What is a species?
A group of organisms sharing a large number of physical features that are able to interbreed to produce fertile offspring.
What is taxonomy & what does it allow?

The identification & naming of organisms.

It allows us to:

- Discover & describe biological diversity

-Investigate he evolutionary relationship between organisms.

- Classify organisms to reflect their evolutionary reltionships.

3 advantages of the binomial system?

1. Unambiguous naming

2. Based on Latin, a scholarly language that can be used all over the world.

3. Implies that 2 species sharing part of their name are closely related.

What are homologous structures?

-Structures that have different functions but have a similar form of developmental origin.

- Indicates a more recent common ancestor.

E.g Pentadactyl limb

What is divergent evolution?

Where a common ancestral structure has evolved to perform many different functions

E.g Homologous Structures.

What are analogous structures?

-2 animals look similar but may not be closely related.

-Don't have a common ancestor but have survived in the same conditions.

E.G whales & dolphins / Butterflies & Bats

What is convergent evolution?

Where structures have similar properties but different developmental origins.

E.G Analogous Structures

5 Techniques for analysing relationships using genetic evidence

1. DNA Sequences

2. DNA Hybridisation

3. Gel Electrophoresis

4. Amino Acid Sequences

5. Immunology

Discuss DNA Sequences as a technique for analysing relationships.

The more closely related species are the more similarities shown in their base sequence.

- This technique has confirmed relationships & corrected mistakes.

Discuss DNA Hybridisation as a technique for analysing relationships.

-DNA is extracted from both species, separated & cut into fragments.

-Fragments from 2 species are mixed & hybridise where base sequences are complimentary.

- The new DNA is heated, the higher the temp. needed to break the H bonds the more closely related species are.

Discuss Gel Electrophoresis as a technique for analysing relationships.

This measures the proportion of DNA & proteins shared between species to estimate the relatedness.

(Looks like chromatography)

Discuss Amino Acid as a technique for analysing relationships.
The more closely species are the more similarities (& less differences) found in their amino acid sequences.
Discuss Immunology as a technique for analysing relationships.

-If you mix the antigens, with specific antibodies of another species, a precipitate will form.

-The closer evolutionary relationship between 2 species the more precipitate formed (more antibody & antigen react).