Biology Unit 1 Flashcards
What are the 2 ways that organisms can be related?
Evolutionary relationships (evolved from the same common ancestor)
Ecological relationships (different species have similar characteristics because they are competing
What were the 3 reasons that many people didn’t believe Darwin’s theory at the time?
It went against religious beliefs because his theory gave an explanation that didn’t need a “creator”
He didn’t know about genes and mutations so he couldn’t explain why new characteristics appeared or how they were passed on to offspring
There wasn’t enough evidence to convince many scientists because not many studies had taken place that supported his theory
What is the theory of evolution?
More than 3 billion years ago, life on Earth began as simple organisms from which all the more complex organisms evolved
What was Lamarck’s theory of evolution?
If a characteristic was used a lot by an organism, it would become more developed through its lifetime
This would then be passed on to the next generation
What is a mutation?
A change in an organism’s DNA
What were the 2 reasons that Darwin’s theory was accepted more than Lamarck’s theory as time went on?
There is now much more evidence that completely supports Darwin’s theory
Lamarck’s theory was rejected because if you dye a hamster’s fur pink and then it has offspring, its offspring won’t have pink fur
How do mutations affect natural selection?
If an individual has a mutation that makes them better adapted to survive in their environment (doesn’t always happen), they are more likely to survive, breed and pass on the characteristic that the mutation caused
What are evolutionary trees?
Diagrams similar to family trees that show how different species have evolved from common ancestors
Describe Darwin’s theory of natural selection
Individuals within a species show variation because of differences in their genes
Individuals with characteristics that make them better adapted to their environment have a better chance of survival so they are more likely to breed successfully
This means that the advantageous characteristics are more likely to be passed on to offspring so a species will gradually evolve
What are the 3 advantages of GM crops?
Can increase yield of the crop making more food
Crops can be engineered to produce nutrients that are required by people in some developing countries
GM crops are being grown elsewhere in the world without any problems already
Describe how embryo transplanting works
Sperm is taken from a good father and egg cells are taken from a good mother
The sperm is used to artificially fertilise an egg cell
The embryo is split many times to form many clones before the cells become specialised
These cloned embryos will be implanted into lots of other cows where they will be grow into offspring that will be clones of each other
What are the 3 disadvantages of GM crops?
GM crops can reduce the number of weeds and flowers which also has many knock-on effects that reduce biodiversity
Many people are worried that a lot of people could have allergies to the GM crops
The transplanted genes could be picked by other unwanted species of plants like weeds
What is genetic engineering?
Altering an organisms genes in order to change its characteristics
What are the 3 issues of cloning?
Leads to a reduced gene pool (fewer different alleles in a population)
Cloned animals are not usually as healthy as normal ones
People worry that humans will be cloned in the future and this would lead to many serious unsuccessful attempts
Describe how cuttings work
Gardeners can take cuttings from good parent plants and plant them to produce genetically indentical copies
This can be done quickly and cheaply
What are the 2 ways that plants can be cloned?
Cuttings
Tissue culture
Describe how tissue culturing works
A few plant cells are put into a growth medium with hormones and they grow into clones of the parent plant
This is very quick and can be done in very little space and be grown all year
What are the 2 advantages of cloning?
Can lead to a greater understanding of the development of the embryo
Could help preserve endangered species
Describe how genetic engineering is done
A useful gene is cut from one organism’s chromosome using enzymes
Enzymes are then used to cut another organism’s chromosome and then to insert the useful gene
Describe how adult cell cloning works
An unfertilised egg is taken and the nucleus (genetic material) is removed
A complete set of chromosomes is taken from an adult body cell
The egg cell is stimulated by an electric shock so that it divides like a normal embryo
It is then implanted into an adult female to grow into a clone of the original adult body cell
What are the 3 main ways that genetic engineering is used?
Genetically modified (GM) crops are engineered to make them resistant to viruses, insects and herbicides
Sheep have been genetically engineered to produce substances like drugs in their milk
Genetic disorders like cystic fibrosis are caused by faulty genes. Scientists are trying to treat these disorders by inserting working genes into sufferers (gene therapy)
What are the 2 ways of cloning animals?
Embryo transplants
Adult cell cloning
What is variation?
How members of the same species have differences
What causes genetic variation?
Members of the species have different genes because they have inherited mixes of genes from different sets of parents
What does the human cell nucleus contain?
All of the genetic material in the form of 23 pairs of chromosomes
What is environmental variation?
How offspring develop because of the conditions they grow up in
How something develops depends on both types of variation
Describe asexual reproduction
X-shaped chromosomes have 2 identical halves
Each chromosomes splits down the middle to form two identical sets of half-chromosomes
A membrane forms around each set and the DNA replicates itself to result in full chromosomes
What is the process of reproduction that happens with animals?
Sexual reproduction
What is the other natural use of asexual reproduction?
It is how all plants and animals grow and produce replacement cells
What is sexual reproduction?
Reproduction involving the fusion of male and female gametes resulting in offspring with a mixture of the parents’ genes
What are genes made from?
Long lengths of DNA
What do the chromosomes contain?
Genes
What is a gene?
The genetic material needed to control the development of one feature of the human
What is the process of reproduction that happens in plants?
Asexual reproduction
Describe sexual reproduction
The gametes have only 23 single chromosomes
The gametes of the father (sperm) fertilise the gamete of the mother (egg) to produce a fertilised egg that develops into the offspring
The genetic variation comes from the mixture of genetic material from the sperm and egg
What is an allele?
Different versions of the same gene are alleles
For example, brown and blue are alleles for the gene for eye colour
What are the 2 types of variation?
Environmental variation
Genetic variation
How do offspring inherit genes from their parents?
Genes from the parents are passed on to offspring on gametes (sex cells) which the offspring develop from
What is asexual reproduction?
Reproduction where there is only one parent so there is no mixing of genetic material resulting in offspring that are genetically identical to the parent
What 2 things speed up decay by microorganisms?
Plenty of oxygen available
Warm, moist conditions
What supplies the energy for all life processes?
Respiration
How do the nutrients that plants have taken from ground and passed up the food chain return to the Earth?
Decay
What happens as you go up a biomass pyramid and why?
The amount of biomass decreases as you go up the pyramid because some of the biomass isn’t consumed (inedible parts of the animal) and waste material isn’t consumed either
What is the carbon cycle?
The natural processes that cause carbon to be recycled over and over again
Describe how compost bins work
Most plant and animal waste can be made into compost
The compost is finely shredded to increase the rate of decay and put into the compost bin
The mesh sides allows air to get in to provide oxygen and the decomposition in the small area allows the area to become warm
Why are there not usually more than 5 species in a food chain?
At the top of the food chain, the amount of biomass that has been lost causes the biomass given to the top predator is minimal
What does the energy for almost all of life on Earth come from and why?
The Sun’s light
This is used in photosynthesis by green plants and algae which are then eaten by animals and so on meaning that the energy from the Sun is passed up the food chain
What are the 5 ways that the carbon is returned to the atmosphere?
When the plants and algae respite, carbon dioxide is released to the air
When animals eat the plants, the carbon is used to make carbohydrates, fats and proteins in the animals
Carbon dioxide is released when the animals respite
When plants, algae and animals die, microorganisms digest the remains and when they respire, they release the carbon dioxide
Microorganisms also digest the animal waste products and release the carbon dioxide when they respire
We also burn animal and plant waste and fossil fuels and release carbon dioxide in combustion
All carbon is returned to the atmosphere in some way
What is the first step of the carbon cycle?
Green plants and algae use the carbon dioxide in photosynthesis
What is a biomass pyramid?
A diagram that shows how biomass passes up a food chain and the amount of biomass going to each consumer
How do you draw a biomass pyramid?
You have to draw rectangular bars equal in height in top of each other with the consumer’s name inside each bar
The producer is at the bottom, the primary consumer is above it, the secondary consumer is above that and so on
The bar widths represent the amount of biomass (not number of thing) in proportion to the others
How does the carbon cycle start?
Carbon dioxide in the air
How does decay work?
The dead remains of the animals and plants and their waste products contain the nutrients originally taken from the ground
These materials are all digested (broken down) by microorganisms and return to the Earth as the basic elements and compounds
What is the main way that energy is lost from most animals?
Loss of heat because animals usually need to be hotter than their surroundings
What are extremophiles?
Microorganisms that are adapted to survive in extreme conditions
What are the 3 main adaptations of Arctic animals and why?
Minimal surface area to volume ratio to reduce heat loss
Thick layer of blubber and thick hairy cost for insulation and reducing heat loss (blubber can also act as an energy store for when food is scarce)
White camouflage to avoid predators or sneak up on prey
What are the 4 living factors that can change an environment that plants and animals live in?
A change in the occurrence of infectious diseases
Change in number of predators
Change in number of prey of availability of food sources
Change in the number or types of competitors
What are the 3 ways that environmental change can affect populations and how does this happen?
Population size increases because if number of prey increases, more food available for predators so number of predators increases
Population size decreases because there is more predators so less prey survive and so on or there is less food or there is more disease
Population distribution changes (some species move to more or different locations)
What are the 3 ways that environmental change can be measured with living indicators?
If there is less lichen in an area, that means that there will be more sulphur dioxide in the air so it can tell us about air pollution
If raw sewage is released into a river, there is more bacteria in the river which uses up the oxygen. Certain species like the mayfly larvae are sensitive to the amount of oxygen in the water and will only be in that water if the amount of oxygen is normal (no sewage)
Certain invertebrate species have adapted to live in polluted conditions so their presence is a good indicator of water pollution
What is an adaptation?
A feature that an animal or plant will have to help them survive in their environment
What do all organisms need to do to survive?
Compete for resources
What do the adaptations of Arctic animals have to do?
Reduce heat loss
What are the 4 main adaptations that desert animals have and why?
Large surface area to volume ratio so that more body heat is lost
To lose less water, they produce concentrated urine and produce very little sweat (they do this by either tolerating big changes in temperature of living in cool areas)
Thin layers of body fat and a thin coat to help them lose body heat
They have a sandy colour to camouflage them to avoid predators or sneak up on prey
What are the 3 adaptations that desert plants have and why?
Small surface area to volume ratio to reduce water loss
Water storage tissues
Deep or extensive roots to absorb as much water as possible
What are the 3 resources that animals need?
Space (territory), food and water
What are the 4 resources that plants need?
Light, space, water and nutrients
What do desert animals have to be adapted to do?
To save water and keep cool
What 3 adaptations can plants and animals have to deter predators?
Armour (eg. roses have thorns)
Poisons (like bees)
Warning colours (like wasps)
What are the 4 ways to measure environmental change with non-living indicators?
Satellites measure temperature of sea surface and the amount of snow and ice cover
Automatic weather stations contain sensitive thermometers that tell us atmospheric temperature change
Rain gauges tell us average rainfall
Dissolved oxygen meters tell us the concentration of oxygen in water
What do desert plants have to adapt to do?
Obtain water where there is little of it
What are the 3 non-living factors that can change an environment that plants and animals live in?
Change in average temperature
Change in average rainfall
Change in level of air or water pollution
What has other use have we found that stains are useful for?
They lower blood cholesterol and risk of heart disease in diabetic patients
What are the 2 ethical arguments against performance enhancing drugs?
It’s unfair to give someone an advantage by taking drugs and not just through training
Athletes may not be fully informed of the health risks that these drugs have
What are the 3 types of drug?
Medicinal (drugs that cure or relieve people of illnesses)
Recreational (legal or illegal)
Performance enhancing (sports)
What are the 3 steps of drug testing?
Tested on human cells and tissues in the lab
Tested on live animals
Tested on human volunteers (clinical trial)
Describe a clinical trial
The drug is tested on healthy volunteers to make sure there is no harmful side-effects when the body is working normally
The drug is given initially as a small dose and increased gradually until the optimum dose is found
The same is then done on people suffering from the illness
Patients are also put into 2 groups where one group is given the drug and the other is given a placebo (fake drug that looks real) to see if the real drug working is also just the placebo effect (when the person thinks they will be cured so they unconsciously make themselves feel better)
What are the 2 ethical arguments for performance enhancing drugs?
Athletes have the right to make their own decision about whether taking drugs is worth the risk
Drug-free sport isn’t really fair anyway because people have access to different facilities, coaches etc.
What are the 2 groups that illegal drugs are divided into?
Soft and hard
Hard drugs are generally more addictive and more harmful
What is thalidomide used for now?
Mainly leprosy
What was thalidomide used for in the 1950s?
Sleeping problems and morning sickness
What are the 3 main reasons that people take drugs?
Enjoyment
Stress relief
Other personal issues
What are statins?
Prescribed drugs used to lower the risk of heart and circulatory disease
What is the main problem with most drugs?
They can change the body’s chemistry enough so that the person is addicted to the drug
Withdrawal symptoms are usually very unpleasant
How were these findings about the uses of statins found?
The original research was done by the government
It compared 2 groups of 3000 patients - those who had taken statins and those who hadn’t
What are the 3 problems with smoking?
Causes heart, lung and blood vessel disease
Tobacco smoke causes cancer
Nicotine is very addictive
What was the disaster involving thalidomide and what did we do to prevent similar things happening in the future?
It wasn’t tested as a drug for morning sickness
It passed through to the foetus causing abnormal limb development
We introduced much stricter drug testing procedures
What 2 types of problems do performance enhancing drugs usually have?
Health issues
Ethical issues
Why are drugs first tested on human cells and tissues?
To see if there is any initial danger with giving humans these drugs
What are drugs?
Chemicals that alter the chemical reactions happening in the body
Why are drugs then tested on animals?
To find out of it does what it is intended to do
To find out about its toxicity and the best dosage
What are the 2 main types of performance enhancing drug and what do they do?
Anabolic steroids cause an increase in muscle size
Stimulants increase heart rate
Give the 3 ways that people who use cannabis often progress on to hard drug use
The effects of cannabis cause people to want to try harder drugs
Cannabis brings people into contact with drug dealers
Genetically, people who take cannabis are likely to also take harder drugs in the future
What are the 4 problems with alcohol?
Affects the nervous system and slows down the body’s reactions
Too much of it leads to impaired judgement, poor coordination and unconsciousness
Excessive drinking can damage the liver and brain
Alcohol is addictive
What is the possible health issue with cannabis?
The chemical could be causing mental health problems
What are the 2 ways that ion content is reduced by the body?
Some ions are lost in sweat
The kidneys remove any excess ions from the blood so that they can be exceeded in urine
What internal temperature does the body need and why?
37 degrees C
Optimum temperature for enzymes to work at
How does the temperature of the environment you are in affect sweat and urine?
When the environment is hotter, you sweat more so you produce less urine so it will be more concentrated
The opposite is true for a cold environment
How is the blood sugar level controlled in the body?
The hormone insulin maintains the right amount of glucose in the blood
How is body temperature controlled?
A part of the brain is sensitive to the temperature of the blood passing through
If the blood is the wrong temperature, it can signal different parts of the body to do what they need to do to correct the temperature
What is homeostasis?
All the functions of the body that try to maintain a constant internal environment
What are the 4 things that need to be controlled?
Ion content
Sugar content
Water content
Temperature
How does exercise affect sweat and urine?
When you’re exercising, you sweat more so you produce less urine so it will be more concentrated
Also, more water will be lost through breath
The opposite is true for when you’re not exercising
What are the 3 ways that water is lost from the body?
Through the skin as sweat
Out of the lungs in breath
As urine (from kidneys)
How is blood sugar level increased?
We eat more carbohydrates to put glucose in the blood
How do we increase ion content in our body?
Eating good with the required ions in it
Describe the 2 ways that auxin controls growth in the shoots
When the shoot is exposed to light, most of the auxin goes to the side in the shade which makes the cell grow more on the shades side so the shoot bend towards the light
When a shoot is growing sideways, gravity causes the auxin to fall down to the lower side and grow more cells there so the plant bends up
What are the 2 agricultural uses of plant hormones?
Most seeds in crop fields are broad-leaved where the crops are narrow-leaved. Certain plant hormone weedkillers only affect the broad-leaved weeds, killing them
Plant cuttings don’t always grow in soil so adding hormone rooting powder containing auxin will cause the cuttings to grow as new plants
What is auxin?
A plant hormone that stimulates and controls growth in the shoots and roots
What would happen to a plant of the tip was cut off and why?
Plant growth will not be controlled and may stop because auxin is made in the tip since the tip is what needs to be controlled
What is the difference between gravitropism and phototropism?
Gravitropism is the growth of a plant in response to gravity
Phototropism is the growth of a plant in response to light
Describe the 2 ways that auxin controls growth in the roots
A root growing sideways will have more auxin on the lower side but in a root, auxin prevents growth so the cells in top grow faster so the root bends down
An uneven amount of moisture either side of a root produces more auxin on the side with more moisture stopping growth on that side so the root grows in that direction to get more moisture
Describe what happens during a reflex arc
There is a stimulus that is detected by the receptors
A signal travels from the receptors down the sensory neurone
The signal is passed from the sensory neurone, down the relay neurone in the spinal cord or unconscious part of the brain to the motor neurone
The motor neurone carries the signal to the effector which contracts (muscle) or secretes hormones (glands)
What is a synapse?
The connection between 2 neurones
What are receptors?
Groups of cells that are sensitive to a stimulus
What are sense organs?
Organs that contain a specific type of receptors to detect a stimulus
What are the 2 types of effector?
Muscles that contract in response to impulses
Glands that secrets hormones in response to impulses
What are the 3 properties of nerves?
Very fast message
Act for a short time
Act on a precise area
What are the 3 properties of hormones?
Slow message
Act for a long time
Act in a general way (less specific than nerves)
What is a reflex arc?
The way that our body gets a stimulus and automatically creates a response
What are the 2 ways that messages are sent round the body?
Hormonal
Nervous
List the 5 sense organs and describe what their receptors do
Eyes (light receptors which are sensitive to light)
Ears (sound receptors sensitive to sound)
Nose (smell receptors sensitive to chemical stimuli)
Tongue (taste receptors sensitive to chemical stimuli)
Skin (sensitive to touch, pressure, pain and temperature change)
What are the 3 types of neurone and what do they do?
Sensory (carries electrical impulses from receptors to the central nervous system)
Relay (carries impulses from sensory to motor neurones)
Motor (carries impulses to the effector)
How do the signals move across the synapse?
Transferred by chemicals called neurotransmitters that move across the gap
What are reflexes?
Automatic responses to certain stimuli that reduce the chance of you being injured or damaged
What are the 3 ways that our bodies fight pathogens?
Skin, hairs and mucus in the breathing system stop a lot of pathogens from getting in your body
Platelets (cell fragments) in the blood help blood clot so that pathogens don’t get in your body via cuts
If pathogens make it through, the immune system kicks in. The white blood cells patrol the blood and attack invading pathogens
Describe how bacteria can become resistant to antibiotics
Bacteria can mutate and sometimes these mutations make the bacteria resistant to the antibiotics
When you are treated, only the non-resistant bacteria are killed
The resistant bacteria survive and reproduce
This means that all of the bacteria are now resistant to antibiotics
What are pathogens?
Microorganisms that enter the body and cause infectious diseases
What must be done in a school lab when culturing microorganisms?
Must be done below 25 degrees C to prevent harmful pathogens growing
Describe what Sammelweis did
He was working in a hospital and saw that many women were dying after childbirth from puerperal fever
He believed that the doctors were spreading the disease from their unwashed hands so he told them all to always wash their hands with antiseptic solution which cut the death rate massively
The antiseptic solution was killing the on the doctors’ hands
What are the 2 advantages of vaccinations?
Vaccines have helped control many infectious diseases that are very serious and even completely stopped some
Big outbreaks of diseases (called epidemics) can be prevented if everyone is vaccinated so that the disease can’t spread
What is the problem with painkillers?
They don’t actually tackle the cause if the disease, just relieve the pain
What are the 3 ways that white blood cells destroy pathogens?
Consuming them (and break them down)
Producing antibodies
Producing antitoxins that counter toxins made by bacteria
What are the 2 main dangers of bacteria?
Diseases made from resistant bacteria are much more common now
A new bacterial disease could come along and no one would be immune so it could spread rapidly
Describe fully how antibodies work
All cells have antigens (unique molecules) on their surface
When white blood cells come across a foreign antigen, they produce called antibodies that lock on and kill the invaders (the antibodies are specific to that antigen)
Those specific antibodies are produced rapidly and are carried around the blood to destroy the rest of that type of pathogen
If someone is infected with the same pathogen again, the white blood cells will very quickly produce the same antibodies again so the person is immune
What is the problem with antibiotics?
Bacteria can quickly evolve inside the body to become resistant to the antibiotics
Why is it difficult to develop drugs that destroy viruses?
They reproduce using your own body cells so it is hard to make a drug that destroys the virus and doesn’t harm your body cells
What are the 2 main types of pathogen?
Bacteria
Viruses
Describe fully how microorganisms are cultured (grown)
They are cultured in a culture medium which is agar jelly with carbohydrates, minerals, proteins and vitamins they need to grow
All equipment is sterilised before use to prevent contamination
Hot agar jelly is poured into shallow round plastic dishes called Petri dishes
When the jelly is cooled and set, inoculating loops (wire loops) are used to transfer microorganisms to the culture medium
A lid has to be taped on the Petri dish to prevent contamination
The microorganisms then multiply
What are the 2 disadvantages of vaccinations?
Sometimes vaccines don’t work
Some people can have serious reactions to vaccines but they are quite rare
How do viruses make us feel ill?
When the cell bursts to release the new viruses, this causes us to feel ill
What are the 3 main dangers of viruses?
They tend to mutate often do it is hard to develop vaccines against them because their antigens keep changing
It is a possibility that a virus could evolve to be very deadly and infectious
In the case of viral epidemics, it can take a long time to develop vaccines against them
What are viruses and how do they replicate inside the body?
They are infections that are not cells and are 100th the size of bacteria
They replicate themselves by invading your cells and using your cells’ machinery to produce many copies of themselves, the cell then bursts releasing all of the new viruses
What are bacteria?
Very small cells (100th of body cell size) which can reproduce rapidly inside your body
What are the 2 ways that bacteria make us feel ill?
Damaging your cells
Producing toxins (poisons)
How do vaccinations work?
When you are infected with a new pathogen, you become seriously ill before the antibodies are produced and you become immune
If a small amount of dead or inactive pathogen is injected, the antibodies for that pathogen are produced and destroy it
You are now immune to that pathogen so without becoming seriously ill. If the real pathogen infects you, the antibodies that destroy it are produced before it can cause damage
Why is antibiotic resistance becoming more common?
Antibiotics are used much more and more than they need to be
The resistant bacteria are spread easily by people
What are antibiotics?
Medicines that actually kill bacteria causing the problem without killing body cells (they are specific to types of bacteria)
They don’t do anything to viruses
What is the advantage and disadvantage of the progesterone-only pill?
Fewer side effects but not as effective
How does oestrogen reduce fertility?
If it is taken every day, it stops the production of FSH meaning that eggs can’t develop
It is taken as a pill
What was the problem with the pill in the past and how has this been solved?
The high levels of oestrogen had many strong side-effects so the amount of oestrogen in the pill was reduced
A progesterone-only pill was also made for people who still had side-effects
What are the 3 disadvantages of the pill?
It isn’t 100% effective
Causes side-effects in some people
Doesn’t protect against STDs
Describe how IVF helped couples to have children
Collecting eggs from the woman and fertilising them in the lab with the man’s sperm
They are grown into embryos and transferred to the woman’s uterus
What is the advantage of this way of increasing fertility?
Helps a woman to become pregnant
Describe the 4 stages of the menstrual cycle
On the day 1, the bleeding starts because the uterus lining breaks down for about 4 days
From day 4 to 14, the lining of the uterus builds up again into a thick spongy layer full of blood vessels ready to receive a fertilised egg
An egg is developed and then released from the ovary at day 14
The wall is maintained from day 14 to 28. If no fertilised egg has landed on the uterus wall by day 28, the lining starts to breakdown and the cycle repeats
What are the 2 disadvantages of this way of increasing fertility?
Doesn’t always work (people sometimes spend a lot of money to get it to work)
Too many eggs could be stimulated resulting in unexpected multiple pregnancies
What does the pill consist of?
High levels of both oestrogen and progesterone
What are the 4 hormones involved in the menstrual cycle?
FSH (follicle stimulating hormone)
Oestrogen
LH (luteinising hormone)
Progesterone
Why does the pill contain progesterone?
It also reduces fertility by producing a thick mucus that the sperm can’t get through
Which hormones can reduce fertility?
Oestrogen
Progesterone
What are the 3 disadvantages of IVF?
Some women have a strong reaction to the hormones
Some reports of an increased risk of cancer
Multiple births can happen if more than one embryo grows into a baby
How do we increase fertility with hormones?
FSH and LH are injected to stimulate egg production and release
What is the menstrual cycle?
The monthly release of an egg from the ovaries and the build-up and breakdown of the protective lining in the uterus
Describe the roles of the menstrual hormones in the menstrual cycle
FSH is produced in pituitary gland and causes egg to mature in one of the ovaries and stimulates the ovaries to produce oestrogen
Oestrogen which is produced in the ovaries causes the pituitary gland to produce LH and stop producing FSH
LH is produced in the pituitary gland and stimulates the release of the egg in the middle of the menstrual cycle
What are the 2 advantages of the pill?
It prevents pregnancy over 99% of the time
Reduces the risk of some types of cancer
What is metabolism?
All of the reactions in the body that keep you alive
List each food group and it is needed for
Carbohydrates to release energy
Fats to keep warm and release energy
Protein for growth, cell repair and cell replacement
Fibre to keep everything moving smoothly through the digestive system
Vitamins and mineral ions to keep all parts of your body generally healthy
What is metabolic rate?
The speed at which the reactions of metabolism take place in someone’s body
What are the 4 problems that can come from eating too little?
Slow growth in children
Fatigue
Poor resistance to infection
Deficiency diseases
What 3 factors affect metabolic rate and why?
Muscle to fat proportion (muscle needs more energy than fatty tissue so a higher metabolic rate is needed)
General size (a bigger person has more cells that need energy)
Gender (men are usually bigger and have more muscle so metabolic rate is higher for men)
What are 4 possible problems that can happen because of obesity?
Arthritis (joint inflammation)
Type 2 diabetes (inability to control blood sugar level)
High blood pressure
Heart disease
When seeing if a slimming product will actually work, what 4 things do you need to check?
The report is a scientific study or in a reputable journal
Written by a qualified person not connected with selling it
Sample of people tested large enough to give reliable results
Other studies that give similar results
In terms of diet information, what does sodium mean?
Salt
What does it mean if somebody is malnourished?
It means that their health is affected because they have an unbalanced diet
What are the 2 ways that inherited factors can affect health?
Some people have inherited factors that affect metabolic rate
Some have factors that affects blood cholesterol level
What are the 2 other problems that can come from being malnourished and what causes them?
Too much saturated fat causes increased blood cholesterol level
Too much salt can cause high blood pressure and heart problems
What is obesity caused by?
Excess carbohydrate or fat in the diet
What are the 2 other factors that affect health?
Amount of exercise
Inherited factors
What is a balanced diet?
A diet that provides the energy you need and not more and also the right proportion of different food groups
What has to be true if a slimming product is going to work?
That it will make you eat less carbohydrate or fat or make you do more exercise
What factor affects someone’s current metabolic rate?
When you exercise, you need more energy so the metabolic rate goes up
What do all metabolic reactions need?
The input of energy
What are the 2 ways that increasing exercise improves health?
Exercise increases the amount of energy used by the body and decreases the amount stored as fat
It also builds muscle that boosts metabolic rate
