Evolution

Question 1

What is a species?

Answer 1

A species is a group of organisms that are capable of interbreeding to produce fertile offspring.

Question 2

What is mass extinction?

Answer 2

A period in time where the extinction rate has increased dramatically.

Question 3

What are the binomial systems in order?

Answer 3

Species
Genus
Family
Order
Class 
Phylum
Kingdom

Question 4

What are homologous structures?

Answer 4

Homologous structures are structures that have been modified through evolution and adaption for different structures - provide evidence for common ancestry.
An example of this is the bones found in the pentadactyl limbs of vertebrates.
This is called divergent evolution.

Question 5

What are analogous structures?

Answer 5

Different organisms with similar features can be the result of very different evolutionary pathways.
An example is a wind of a bird and insect.
These organisms have developed similar body shapes and adaptions to their environment through the process of convergent evolution.

Question 6

What biological techniques are there for determining evolutionary relationships? (3)

Answer 6

> Comparisons of amino acid sequences in proteins
DNA Hybridisation - comparisons of base sequences in genes (sections of DNA)
Biochemical methods can reduce the mistakes made in classification due to convergent evolution

Question 7

What kingdoms are there? (5)

Answer 7

Prokaryote, Protoctista, Fungi, Plantae and Animalia.

Question 8

What phylums do you need to know? (3)

Answer 8

Annelida, Chordata and Arthropoda.

Question 9

What classes do you need to know? (4)

Answer 9

Insecta, Arachnida, Crustacea and Myriapods.

Question 10

What is the prokaryote Kingdom? (3)

Answer 10

> Contains bacteria and blue-green algae
Unicellular and possess no membrane bound organelles
Cell wall made of murein or peptidoglycan

Question 11

What is the Protoctista kingdom? (2)

Answer 11

> Mostly small eukaryotic organisms

>Kingdom includes Protozoa like amoeba, slime moulds and algae.

Question 12

What is the Kingdom Fungi? (3)

Answer 12

> Eukaryotic organisms composed of a network of threads called HYPHAE
Cannot photosynthesise and are heterotrophic, either saprophytic or parasitic
Cell wall made of chitin

Question 13

What is the Kingdom Plantae? (3)

Answer 13

> Multicellular eukaryotic organisms
Possess chloroplasts which carry out photosynthesis, and so are autotrophic
Cell walls made of cellulose

Question 14

What is the definition of biodiversity?

Answer 14

Biodiversity refers to the number of species on a planet.

Question 15

What is the Kingdom Animalia? (3)

Answer 15

> Multicellular eukaryotic organisms
Lack cell walls and feed heterotrophically
Animals show nervous co-ordinations

Question 16

Describe the phylum Annelida? (5)

Answer 16

> Long, thin, segmented body for a large surface area
Hydrostatic skeleton so they’re fluid under high pressure
Thin, permeable skin across which has exchange takes place
Closed circulatory system so all blood is enclosed in blood vessels
Blood contains a respiratory pigment to carry oxygen

Question 17

Describe the phylum Chordata. (5)

Answer 17

>Vertebrate column/backbone
>Well developed brain enclosed in a cranium
>Closed circulatory system
>Blood contains a respiratory pigment - haemoglobin 
>5 Classes:
-Fish
-Amphibians 
-Reptiles
-Birds
-Mammals

Question 18

Describe the phylum Arthropoda (7)

Answer 18

> Largest phylum in animal kingdom in terms of number of species
Body divided into segments
Well developed brain
Open circulatory system so blood is all over body
Support and protection provided by hard exoskeleton made of chitin, often covered in a wax layer to reduce water loss
Pairs of jointed legs
4 Classes
-Insects
-Arachnids
-Myriapods
-Crustacea

Question 19

Describe the class Insecta. (2)

Answer 19

> 3 pairs of legs

>Gas exchange by gills in aquatic insects and by trachea in terrestrial species

Question 20

Describe the class Crustacea
(2)

Answer 20

> Between 5 and 10 pairs of legs

>Includes crabs, lobsters and woodlice

Question 21

Describe the class Arachnida (2)

Answer 21

> 4 pairs of legs

>Includes spiders and scorpions

Question 22

Describe the class Myriapods (3)

Answer 22

> Body split into many segments
1 or 2 pairs of legs per segment
Includes centipedes and millipedes