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11.5 Adaptation and Competition


To survive, organisms require a supply of materials from their surroundings and from the other
living organisms there.

Organisms live, grow and reproduce in places where, and at times when, conditions are suitable.

Physical (abiotic) factors:

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The camel can go without food and water for 3 to 4 days.
Fat stored in their humps provides long term food reserve, and a supply of metabolic water.
The fat is not distributed around the body; this reduces insulation, allowing…

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11.6 Reproduction and Variation

Genetic material

A cell is the basic unit of life; all organisms are made up of cells.
The nucleus is a large organelle found in all cells, that contains the genetic information. (Even
red blood cells once had…

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Humans can carry out various procedures to create clones of plants and animals.
These new individuals (clones) are genetically identical to the parents.

New plants can be produced quickly and cheaply by taking cuttings from older plants.

Tissue culture

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Genetic engineering

Genes from the chromosomes of humans and other organisms can be cut out using enzymes and
transferred to cells of other organisms.

GM = Genetically modified

Examples of uses in food production:
GM soya
GM tomatoes
Enzymes used to make…

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Other uses of genetic engineering

Genes can also be transferred to the cells of animals or plants at an early stage in their development
so that they develop with desired characteristics:
Gene therapy in could be used to insert healthy genes into…

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11.7 Evolution

The theory states that all species of living things which exist today have evolved from simple
life-forms which first developed more than 3 billion years ago.

Origins of life
These first organisms were very simple single-celled organisms, similar to bacteria.…

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Most mutations are harmful or fatal. Occasionally, some mutations are useful.

How do mutations occur?
o Errors occur when the DNA is replicated prior to cell division:
o Errors may occur when chromosomes are separated during cell division:

What do mutations do?…

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11.8 Human's Effect on the Environment

Human Population Explosion

The human population is growing rapidly due to an increase in the standard of living.

Waste Production

Raw materials including non-renewable energy resources are rapidly being used up and
increasingly more waste is…

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Waste may pollute:
water with sewage, fertiliser or toxic chemicals;
air - with smoke and gases such as sulphur dioxide;
Land - with toxic chemicals, such as pesticides and herbicides, which may be washed from
land into water.

Sulphur dioxide contributes…


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