3.15 Genes

• A gene is a section of a molecule of DNA
• Genes are located in the nucleus
• A double helix shaped gene carries information of the characteristic of the organism
• Information of the gene is passed to the cytoplasm.
• After passing into the cytoplasm the gene is then turned into a protein
• Protein controls the characteristic of the gene.

3.14 Chromosomes

• A chromosome is the genetic information inside a cell. 
• Genes control the production of protein which controls a characteristic.  
• The DNA forms a shape called "the double helix"
• There are 1000's of genes in a chromosome
• Each different species have different amount of chromosomes. 
• Chromosomes operate in pairs which are based on length.

3.1 Describe the differences between sexual and asexual reproduction

4.14 enhanced greenhouse gases

- when gases increase in concentration
- the UV rays are increasingly re-emitted, warming the earth
- this is global warming
- this can lead to: melting ice caps, raising sea levels. This causes many floods in low lying countries
- climate change happens can cause change in sea level temeperature causing coral bleaching

4.13 greenhouse gases

- burning of fossil fuels = CO2, NO2, SO2
- farming- cows emitt methane (from farting)
- evaporation of water- clouds contribute to greenhouse effect
- canned sprays- CFC's break down the ozone layer

4.12 greenhouse effect

- UV light comes from the sun
- 50% of this is reflected
- UV light is is converted as infrared and absorbed
- infrared gets emitted back out
- greenhouse gases re-emitts and re-distributes infrared
- more greenhouse gases = more heat
- CFC's break down the ozone layer

4.11 gas pollution

- burning of fossil fuels results in sulphur dioxide gas
- this comes from factories and cars
- SO2 + H2O = sulphuric acid = acid rain
- acid rain can kill fish in the lakes and rivers
- carbon monoxide - fossil fuels are burned without oxygen
- blocks haemogloblin from carrying oxygen
- can lead to light headedness, a headache and in worst case death. This is caused by not having enough oxygen. In your body