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They are produced by meiosis
Non - identical
It involves the fusion of the male and female gametes. This process is called fertilisation
They are mixed around recieveing information from male and female parents
It allow for variation as each gamete is different form one another
No gametes involved
Genetic information is not mixed
Offspring is genetically identical to the parent.
There is only one parent
Only in reproductive organs
In the first tage all the chromosomes are copied in a cell in the human reproductive organ.
The cell then divides into two, then these cells divide again forming 4 non identical gametes cells
The new cell begins to divide by mitosis producing a clump of identical cells called an embryo
As the cells develops the cells differentiate into different cell types such as blood cells and nerve cells
Inside chromosomes
It contains 2 strands each one being a polymer
They wrap around each other forming a double helix
It is a small section of DNA on a chromosome
They code for a specific sequence of amino acids to create a specific protein
It is the entire genetic material of an organism
A different version of the same gene
It tells us the allele that codes for the specific characteristic
Homozygous is when a person has 2 copies of the same gene
This is when a person has 2 different versions of the same gene
It tells us the characteristics expressed caused by the a persons alleles
An allele that is always expressed even if one copy of it is present
An allele that is only expressed when 2 copies of it are present
It is a disorder of the cell membrane. It is a recessive genteic disease
It causes extra fingers or toes. This is a dominant genetic disease
Embryos are tested to see if they have alleles for inherited disorders
Embryos without the inherited disorder are implanted into the woman which develop into healthy offspring
Embryo screening is expensive
Large number of embryo produced but only are implanted. The rest are destroyed causing this to be unethical
Male - XY chromosome
Female - XX chromosome
The difference in characteristics of different individuals inside a population
1. Alleles - genetic cause
2. Environment
3. combination of 1 and 2
It is a random change in the dna
3 billion years ago
When members of a speices have alleles that are better suited for survival than others they will be more likely to survive and reproduce to create offspring who also have that allele. e.g rabbits with thicker fur are better in the cold environment then rabbits with smaller fur
The change in inherited characteristics over time through the process of natural selection
Get a population of an animal and choose the one most fitting to what you desire. Breed them so they can reproduce and bring offspring. Choose the offspring that is the most fitting and carry it out again until all offspring fit the desire
Inbreeding - some breeds may be prone to disease or inherited disorders
When genes from one organism are cut out and transferred to another
Could be bad for insects and plants
Not enough research done on the effects on health
When scientists attemp to use genetic modification as an attempt to treat inherited disorders in humans
Identify the gene you want to transfer. Use enzymes to isolated these genes and transfer it to a small circle of DNA known as a plasmid. The desired gene is then transferred to the target organism. Make sure that this is done at a very early stage of the organisms developkment to ensure that all the cells have the desired gene
Remains of an organism from millions of years ago that are found in rocks
- When parts of the organism has not decayed. This could be because some of the conditions for decay are absent such as no oxygen
- Can form when parts of the organism are replaced by minerals during the decaying process
- Can be traces of organisms such as footprints and burrows and plants can leave preserved spoaces where the roots one were
- Catastrophic events
- Environmental changes
- Disease
- New predator
- New competition
When anit-biotics are used in high amounts some bacteria might undergo a mutation causing it to be resistent toit. This bacteria will reproduce and create many antibiotic bacterium
- Not prescribing inappropriately such as using it for a virus
- Patients make sure to complete course to ensure all bacteria is killed
- Restrict the use of antibiotics in farming
Kingdom
Phylum
Class
Order
Family
Genus
Species
Naming organisms based on their genus and species names
Developed by Carl Woese comparing biochemistry of different organisms
The regulation of internal conditions of a cell or an organism to maintain optimum conditions for a function in response to internal and external exchanges
- Blood glucose concentration
- Body temp
- Water levels
Stimulus is detected by receptor cells, sent to brain to process the info and sends instruction to the effector which is a muscle or a gland to carry out the resposne
The stimulus is detected by the recepter cells and an alectrical impulse is sent to the relay neuron. to reach the relay neuron a chemical is ejecvted and crosses the synapse through diffusion and reaches the relay neuron. The information is processed into an instruction and then sent across to the motor neuron. This motor neuron sends the electrical impulse into the effector which is a muscle or a gland and the response is carried out
A stimulus such as high heat are detected by receptor cells. An electrical impulse then travels across the sensory neuron to pass the synapse a chemical is released and it diffuses to the relay neuron. However it doesnt go to the brain but passes it. Once the synapse is reached again a chemical is released and the impulse travels to the motor neuron and then the effector in this case is a muscle and the reaqaction is carried out
A number of glands that release hormones to regulate internal condititons
Pancreas
Ovary/testes
Thyroid - located in the throat
Adrenal glands - on top of the kidneys
pituartary gland - Master gland, releases a number of diff hormones into the blood depending on the conditions
Example, after a meal with losts of carbs blood glucose level can increase, insulin reduces the suger lvls in the blood by storing it in the muscle and the liver cells as glycogen.
Pancreas does not produce enough insulin
Body does not react to the insulin produced in the pancreas
Obesity
It is release by the pancreaas when blood sugar concentration is too low. It triggers for the stored glycogen in the liver and muscle cells to be converted back into glucose and is released into the blood.
- FSH causes an egg to mature inside the ovary. Triggers the release of oestrogen
- Oestrogen causes the lining of the uterus to become thick in preperation of the arrival of the egg. Inhibits the release of FSH triggers the release of LH
- LH triggers ovulation/ the release of the mature egg Once the ovary has released the egg progesterone is produced
- Pregesterone maintains the uterus lining - Inhibits the release of FSH and LH
The different wways fertalisation can be prevented
Oral pills - contain hormones that prevent the body from producing FSH Highly effective however it must be taken everyday. Can lead to breast cancer or blood clots
Progesterone Injection - Stops eggs from maturing or being released. Last for long time. Dont protect against sexually transmitted diseases
Barrier method (condomn or diaphram)- Trap sperm and use a spermicide to kill the sperm Howevery they can slipp or break off
FSH and LH are injected into the woman causing the women to ovulate more then usual increasing her chances of becoming pregnant through sexual intercourse
The mother is first treated with FSH and LH which causes several eggs to mature. These eggs are then collected by mother. Sperm from the father is collected and used to fertilise the eggs in the laboratory. The fertilise eggs then develop into embryos and are inserted back into the mothers uterus
Low sucess rate
Emotionally stressful
Physically demanding on the mother
Can lead to unwanted multiple births
Expensive
Some embryos destroyed
Released in time of fear amd stress into the blopodstream
- Increases heart rate more oxygen and glucose transported to muscle cells and the brain preparing for a fight or flight response htrough aerobic respiration
Simulates the bodies basal metabolic rate (Metabolism is the sum off all the reactions that take place in the body)
- Important in growth and development
The level of thyroxine in the blood is monitored by the brain. When the thyroxine level falls the pituatary gland stimulates the release of TSH into the bloodstream. Triggers the thyroid release more thyroxine. The increase in thyroxine is detected by the brain and then it inhibits the release of TSH
the action taken by the body to return something to a normal optimum level following a deviation from that level
The environment in which an organism lives
The total number of the same species living in the same geographical area
biotic - living
abiotic - non living
It is the biotic and abiotic parts of the environment and how they interact
Light
Space
Water
Mineral ions
Food
Teritory
Mates
Water
- Availability of food - less food reduction in organisms
- New predators - creates competition
- Competition - species can be outcompeted
- Disease - can spread and kill all
- Light intensity - photosynthesis
- Temperature
- Water lvls
- Ph level of soil
- Mineral lvl in soil
- Wind intensity
- CO2 and oxygen
Organisms that live in very extreme conditions
They synthesise complex molecules - These are called biomass
A create a grid with coordinates. Use a random number generator to generate the coordinates. Place the quadrat in the coordinated location. Then count all organisms in the quadrat. Do this multiple times for higher valididty
CO2 starts in the atmosphere and is absorbed by plants to use for photosynthesis. Carbon is used to make carbs fats and proteins. Plants and algae alson respire so some CO2 is returned to the atmosphere. Once animals feed on the plant and then an animal feeds on that animal the CO2 in the plant passes through the animals. Animals aerobically respire to release C02 into the atmosphere. Animals release waste products and dead remains. Then decomposers decompose the waste and dead remeains. Whwn they respire C02 is released back into the atmosphere. The carbon in the waste is also returned
The variety of all species living in an area
High biodiversity means there are alot of species so that means that the ecosystem is less dependednt on one species so if the population of one speceies falls it is less liekly to affect the entire ecosystem
For rice fields or grazing cattle. Can be used for growing biofuels
By sewage and fertilisers when it rains, toxic chemicals killing animals in the river
Certain chemicals can produce acid rain smoke can kill animals
Land fills - Can destroy habitats, Toxic chemicals can leach out and effect nearby soil
Houses
Airports
Factories
Farms
Landfills
They contain large amounts of dead plant material conditions in the peat reduce the rate of decay making them huge carbon sinks as they trap carbon alot howvever they are being destrpyed
As compost
As biofuel to produce energy - This reduces biodiversity via the destruction of habitats