BY2.1

Question 1

Where does the highest and lowest biodiversity exist?

Answer 1

Highest = equator (rainforest=terrestrial, coral reefs=aquatic)

Lowest = poles

Question 2

What is the mechanism that new species arise from?

Answer 2

Natural selection from a common ancestor

Question 3

Name the animal used to show natural selection from a common ancestor

Answer 3

Finches from South America to the Galápagos Islands

Question 4

Describe the process of natural selection

Answer 4

• within the common ancestor species genetic variation exists due to mutation
• there is an overproduction of offspring within a population e.g. Common ancestor finches arrive on the one island and interbreed
• however the population level remains constant due to a high mortality rate
• the overproduction if offspring leads to increased competition, therefore only certain individuals will have beneficial characteristics with give them a selective advantage to the main selection pressure
• these are more likely to survive and reproduce, therefore their offspring are more likely to inherit the beneficial characteristic
• if this process continues from generation to generation the beneficial characteristic frequency will increase in the population

Question 5

Name the 2 main ways organisms are classified (classification systems) and describe each

Answer 5

Taxonomic system - uses the principle of hierarchy. Take a large group of organisms and divide them into smaller groups, and each member of each group shares common features/characteristics/traits e.g genes/proteins/morphology. There can be no overlap i.e. 1 organism can be placed into 1 group

Phylogenetic system - the system allows us to see the points of divergence from the common ancestor group, and it allows us to see how closely related groups are because of their points of divergence.

                 \_\_\_\_\_ amphibians 
Fish\_\_\_\_\_/ 
              / 
            /
Common ancestor

Question 6

Name the different stages of the taxonomic model and the way to remember it

Answer 6

Kids Play Carelessly Over Farmer Giles Styles

Kingdom (Anamalia)
Phylum (Chordata)
Class (Mammalia)
Order (Primates)
Family (Hominidae)
Genus (Homo)
Species (sapiens)

Question 7

How do we name organisms?

Answer 7

Binomial system
Uses the Genus and Species Taxa
E.g. Homo sapiens = humans
This system avoids confusion of dealing with local names and different languages

Question 8

What are the 2 main sources of evidence to support evolution

Answer 8

Fossil record morphology and Biochemical Analysis

Question 9

We can only use certain fossil record morphology data to support evolution if they have….?

Answer 9

Homologous structures

Question 10

Example of a homologous structure

Answer 10

Pentadactyl limb
E.g. Seal flipper = swimming
Bird wing = flying

Question 11

What is a pentadactyl limb

Answer 11

Same structure, different functions

This is an example of divergent evolution from a common ancestor

Question 12

What is an analogous structure

Answer 12

Different structure, same function
E.g. Bird wing and insect wing
Example of convergent evolution and CANNOT be used as evidence of evolution from a common ancestor

Question 13

Describe biochemical analysis

Answer 13

Involves comparing the DNA base sequence (DNA fingerprinting), or amino acid sequence (in a protein) the more similar the sequence (DNA base/ Amino acid) the more closely related the species are
Most accurate way of determining relatedness

Question 14

Which 3 phyla Taxa must we be familiar with

Answer 14

Chordata, Arthropoda, Annelida

Question 15

What is the gas exchange surface, habitat and body covering of fish

Answer 15

Gills
Water
Scales

Question 16

What is the gas exchange surface, habitat, body covering of amphibians

Answer 16

Soft moist skin and simple lungs
Land but need water for life cycle
Soft moist skin

Question 17

What is the gas exchange surface, habitat, body covering and gestation of reptiles

Answer 17

Simple lungs
Land
Dry scaly skin
Lay eggs with leathery shells

Question 18

What is the gas exchange surface, body covering, gestation and other characteristics of birds

Answer 18

Lungs
Feathers
Eggs with hard shells
Forelimbs modified for flight, endothermic

Question 19

What is the gas exchange surface, body covering, gestation and other characteristics of mammals

Answer 19

Lungs
Hair
Internal gestation
Endothermic, double circulation, mammary glands, sweat glands

Question 20

What are the 5 classes of the phylum Chordata

Answer 20

Amphibians, reptiles, birds, mammals, fish

Question 21

What is the one class of arthopoda we need to know

Answer 21

Insects

Question 22

What are the 2 important characteristics of Arthropoda and why are they important

Answer 22

Jointed legs - modified to perform a variety of functions, including walking, swimming, jumping, feeding and reproduction
Exoskeleton - the outermost layer of cells of the body secretes a thick wax cuticle, which consists mainly of chitin. This performs several functions
• in the most terrestrial Arthropods the exoskeleton is covered with a layer of wax (chitin) which reduces water loss
• protection of internal organs and from predators
• provides a point of attachment for muscles

Question 23

What is the main disadvantage of the arthropods exoskeleton

Answer 23

It’s fixed in size and doesn’t grow with the animal. In order to grow an arthropod must periodically shed its exoskeleton (ecdysis). This leaves the animal especially vulnerable as the new exoskeleton hardens

Question 24

What is the body structure, circulatory system, nervous system, gas exchange surface and locomotion of Annelida

Answer 24

• Segmented body, divided internally by partitions (septa)
• Closed circulatory system containing oxygen carrying pigment e.g. Haemoglobin
• nervous system with a primitive brain
• thin, permeable, moist skin
• hydrostatic skeleton

Question 25

What is the body structure, circulatory system, nervous system, gas exchange surface, and locomotion of Arthropoda

Answer 25

• segmented body. Further divided into head, thorax, and abdomen. Hard outer exoskeleton made of chitin (water proof)
• open circulatory system, made up of a cavity which surrounds the body organs called haemocoel
• nervous system with a well developed brain
• tracheole tubes
• paired jointed legs

Question 26

What are the 4 main characteristics of the insect class of Arthropoda

Answer 26

Antenna, compound eyes, wings (x2), 3 pairs of jointed legs

Question 27

What is biodiversity?

Answer 27

A measure of the different organisms present in a habitat/planet