B3 - Living and growing

A section of a chromosome made of DNA

A trouser made of denim

The characteristics expressed by an individual

It codes for a particular protein

It allows protein synthesis to occur outside of the nucleus

Growth

To make gametes

Repair

Sexual reproduction

Asexual reproduction

1. A double helix unzips to form two single strands of DNA

1. It pairs up with another strand of DNA

1. Half of the bases are removed from the DNA

2. New complementary base pairs join up with the existing ones

2. The two strands wind back together but in a different order

you can grow larger

it allows cell differentiation

organisms can become more complex

you have spares in case some cells die

communication systems between cells

a system to supply cells with nutrients

a system to control exchanges between cells

a larger surface area

people think it's wrong to interfere with nature

cloning animals will cause mutants that revolt against humans, e.g. the wererabbit

Cloning people will make someone that is not a real individual and that is wrong

People are worried about the health risks of genetically engineered food

People are worried that genetically engineered food wont taste nice

People are worried that genetically modified plants/animals will disrupt the natural ecosystems

Some people think it's morally wrong to create new life forms or move genes between species

Some people are worried that the animal will lose connections with its friends if it is genetically modified and its friends aren't

Mass producing animals with desired characteristics, e.g. cows that produce a lot of milk

Producing lots of animals that have been genetically modified to provide human products

producing human embryos to provide stem cells for research and therapy

It allows blood to be pumped at a higher pressure

Blood can be pumped faster

The blood doesn't have to travel as far

Plant cells retain the ability to differentiate

Plants can keep growing forever

Animals can keep growing forever

Plant cells mainly grow by enlarging whereas humans grow by cell division