3.14 Chromosomes

• Chromosomes are the genetic information within a cell. 

• The chromosomes are composed of a molecules called DNA (DeoxyriboNucleic Acid).

• Section of the chromosomes are called genes. 1 chromosones will have many genes.

• Each genes carry the information for the construction of protein.

• protein gives us characteristic association with the gene eg blood.

• Different organism have different amount of chromosomes                                                                                                                 
• Chromosomes operates in pairs = Homologous pairs.

The gene loci = same gene

characteristic has 2 version of each gene = called Alleles

3.1 Sexual and Asexual reproduction

Sexual reproduction

1. organism that show sexual reproduction show sexes, which we can define as male and female
2.they manufacture cells named gametes which take the form in a male as a sperm cell. In the female it takes shape as a egg.
plant ---> sperm cell is called pollen grain
---> egg cell is called ovule
3. the cell division that produces gametes is called meiosis
affect of meiosis is half the total of adult chromosones in the gamete cell.
Humans ---> total number of chromosones in cells is 46
in gametes the total number is 23 and from going to 46 to 23 is happening by the process called meiosis.
4. in sexual reproducing population there is the process called fertilisation, this is when the gametes cell of the male and female fuse together.
5.in the population we find variation (difference), which is broad

asexual reproduction 

1. asexual reproduction have no sexes
2. populations have no gametes
3. no meiosos but there is mitosis in nucaritotic cells and binary fission
in these cells the chromosones remain constantly
4. there are no gametes there is no cell fusing
5.this population shows small amount of variation due to muatation
and if they are identical know as a clone


( Credits to Jesper Kwant Corrected by Numob <3)

4.9 Carbon Cycle

1. Photosynthesis
Co2 + H20  are combine in photosynthese using clhorophyll to trap the light energy to make glucose and oxygen.


Co2 come from atmosphere. 


Photosynthesis when occur is responsible for reducing the atmospheric Co2.


2. Feeding - passage of carbon in the different trophic levels.
 Higher trophic levels will take up the lower trophic levels carbon  and travel through the food chain . Use carbon for growing.
eg. Producer -> Primary consumer -> Secondary 
consumer


3. Respiration - It adds Co2 to the atmosphere.
All organism give off Co2 to the atmosphere by respiration.


4.Decomposition -
All of the organisms will die at some point and the organic molecules are broken down by decomposer organisms (bacteria, fungi) -> carbon dioxide being released back to the atmosphere.


5. Combustion - 

• fossil fuel ( oils and coals) are combusted to release CO2. -> mainly by Industrial and vehicles
•  Environment naturally -> lighting striking plants ->forest fires / grassland

4.14 Enhanced Greenhouse effect

Enhance of greenhouse effect -> produce by pollution ( carbon dioxide, Methane, water vapour). These gasses Increased in their concentration in the upper atmosphere.


Consequences are that infra-red light re-emitted backward to earth. This raise the average global temperature = GLOBAL WARMING. 


Diagram showing the process.
Red = Infra-red light 

Consequences of global warming 

• Melting Ice caps
• Raised Sealevels
• Ocean current
• Winds
• Climate change

Changes distrubution of the Biomes -> " Ecosystem"

4.13 Greenhouse Gases

1. The burning of fossil fuel from factories and vehicles and burning of coals from domestic.


2. Farming - Animals in their digestion of crops -> Cows produce methane gas to the atmosphere ( 9%)


3. Evaporation of water -> form water vapour -> clouds


4. Refrigeration of solvents -> CFC ( combination of chlorine, flurine, and carbon) associate of the absorption of UV light and catalysing the Ozone layer.

4.12 Greenhouse Effect

a) uv-light (sun) short or high energy
b)50% of the light reflect back to space
c) Absorption of earth surface
UV light convert to infra red
d) Infra red light - then reflect backward
e) some of this lost to space - heat
f) Some of the green houses ( water vapour, Co2, Ch4) will re emits the infra red but it re-distrubetes -> some will go down back to earth surface.

 Enhanced greenhouse effects refers to the thickening of the greenhouse gas layer through pollutants such as carbon dioxide, methane which will absorb more infra red which will raise the temperature and can lead to climate change.

CFC - well known on the effect on the ozone layer.

4.11 Gas Pollution

Consequences of pollution
1. Sulphur dioxide
- Is made by the combustion of fossil fuels ( power station) and is also contributed by the Vehicles. In the atmosphere when sulphoric dioxide combines with water ( vapour)(SO2+H2O=>Sulphuric Acid)which forms sulphuric acid where its found in water condense to cloud. When it rains , it is called acid rain. 
Acid rain can cause the plant to 
1.'burn' tree when fallen and the sulphuric acid 
2. causes Calcium and Magnesium to be leached out of the soil, without calcium and magnesium ions in the soil the plants will cause the leaves to turn yellow/wither and the plant can't grow. 
The precipitation will form streams and goes to the lake which will reduce the ph of the lake (because its acidic) the affect is that it brings the release of aluminium ions (Al3+) which causes the thickening of mucus in the fishes gills which reduces the ability of fish to obtain oxygen through water and the fish suffocates and dies.

2. Carbon Monoxide is a gas added to the atmosphere by the combustion of fossil fuels (more particularly coal) burned with insufficient oxygen. Carbon monoxide combines with our haemaglobin inside our blood and blocks haemaglobin from carrying oxygen which reduces oxygen circulation. This is toxic. ( credits to daniel lo)