The test-tings

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Good luck... you have exam you should be on tumblr.

i dont know why i am.

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the reasons for the conservation of animal and plant species, with reference to economic,

Economic

Growth of timber, food and fuel

Sources of new medicines

Ecotourism

Ecological

Regulation of atmosphere and climate

Photosynthesis removes CO2 and replaces it with O2

Purification and retention of fresh water

Formation and fertilization of soil

Without soil, we couldn't grow crops

Detoxification and recycling of wastes

Crop pollination

Ethical

All living organisms have the right to survive and live in the way in which they have become adapted. 

The loss of habitats and biodiversity can prevent many organisms from living where they should

Aesthetic

Studies have shown that patients recover more rapidly from stress and injury when they are exposed to pleasing natural environmental conditions

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EVOLUTION: outline the behavioural, physiological and structural adaptations of organisms t

Behavioural

An aspect of behaviour of an organism that helps it to survive the conditions it lives in. An earthworm withdraws into a burrow when touched to avoid being eaten

  Physiological/biochemical

An adaption that ensures correct functioning of cell processes. Yeast can produce enzymes to respire different sugars that are present

  Anatomical

A structure that enhances the survival of the organism. Bacteria have flagellae to enable them to move independently

[geneticist]

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EVOLUTION: explain both genetic and environmental causes of variation

Genetic

Our genes define our characteristics, and the combination of alleles that we inherit from our parents is unique. Unless a person has an identical twin, there is little chance of 2 people having the same combination of alleles, so everyone’s characteristics are unique

Environmental

Many characteristics can be affected by the environment- if a tree that would normally grow to 6m was planted where there was little soil or water, e.g. a rock crevice, it might only grow to 1.5m. If a pet was overfed, it would become obese

[geneticist]

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Insect wings (source)

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EVOLUTION: describe the differences between continuous and discontinuous variation

Continuous variation is where there are two extremes and a full range of values in the middle. Most individuals are close to the mean, but there is a minority at each extreme. Characteristic is coded for by multiple genes and environment has a large effect on it

Height in humans

Length of leaves on a tree

Length of stalk of a toadstool

Discontinuous variation is where there are distinct categories and no intermediate values. There may be an equal spread between the categories, or there might be more of one type than another. Characteristic coded for by one gene which the environment has no effect on

Sex

Male or female in mammals, male, female or hermaphrodite in plants

Human blood groups A, B, AB or O

Some bacteria have flagella, others do not

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EVOLUTION: discuss the fact that variation occurs within as well as between species

Variation occurs within a species- eye colour, hair colour, height- as well as between species, which are obvious differences; birds fly whereas dogs do not.

[forestsonriverdaughter]

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EVOLUTION: define the term variation

Differences within or between species

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Uses of collagen

found in the walls of the arteries preventing arteries from bursting as a result of high blood pressure being pumped from the heart.

form tendons connecting bones to skeletal muscle to allow movement.

bones are formed from collagen reinfoced by calcium phospate

cartilage and connective tissue formed from collagen

collagen is injected into lips to make the fuller.

[mariennesilverleaf]

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Collagen lip injection

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collagen structure

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collagen is a fibrous protein.

made of 3 helical polypeptide chains, each about 1000 amino acids long, wound around each other (like a plat) and held together by hydrogen bonds. Every 3rd amino acid is glycine allows the 3 polypetide chains to be held closer toger.

Each triple helix is covalently bond bonded to adjecent triple helices. The covalent bond are known as cross links. These cross links are staggered

to make the molecule stronger.

Collagen is strong and flexible but does not stretch.

[likeafieldmouse-deactivated2015]