biology topic 2 organisation
- Created by: harjot hayre
- Created on: 23-02-18 19:17
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- organisation
- cell organisation
- large multi- cellular organisms
- made up of organ systems
- have different systems for exchanging and transporting substances
- tissues
- a group of similar cells that work together to carry out a specific function.
- organs
- a group of different tissues that work together to perform a certain function.
- organ systems
- a group of organs working together to perform a particular function
- plant cell organisation
- structure of leaf
- 1)epidermal tissue covered in waxy cuticle
- 2)upper epidermis is transparent
- 3)palisade layer has lots of chloroplasts
- 4)xylem& phloem form network of vascular bonds
- 5)tissues of leaves adapted to gas exchange
- structure of leaf
- large multi- cellular organisms
- enzymes& digestion
- enzymes
- carbohydrases
- convert carbohydrates into simple sugars
- made in: salivary glands, pancreas, small intestine
- proteases
- convert proteins into amino acids
- made in: stomach, pancreas, small intestine
- lipases
- convert lipids into glycerol and fatty acids
- made in: pancreas, small intestine
- carbohydrases
- digestive enzymes
- break down big molecules eg: starch,proteins and fats
- make smalller molecules like sugars, amino acids,glycerol& fatty acids.
- bile
- neutralises stomach acid & emulsifies fats
- breaks fat into tiny droplets
- neutralises stomach acid & emulsifies fats
- digestion
- salivary glands
- produce amylase enzyme in saliva
- gullet
- oesophagus
- pancreas
- produces protease, amylase and lipase enzymes
- stomach
- produces protease enzyme, pepsin
- gall bladder
- bile stored here before being released into small intestine
- liver
- bile is produced here. which neutralises stomach acid and emulsifies fats
- large intestine
- excess water is absorbed from food here
- rectum
- faeces held here until released through anus
- small intestine
- 1)produces protease, amylase and lipase enzymes to complete digestion
- 2)digested food absorbed here
- salivary glands
- enzymes
- the lungs
- alveoli
- 1) little air sacs in the lungs. gas exchange happens here
- 2) blood passing to next alveoli has just returned to the lungs from rest of body.
- 3) when blood reaches cells oxygen is released from RBC's and diffuses into cells
- 4)at same time co2 diffuses out of cells into blood then carried back to lungs
- breathing rate
- =number of breaths/number of minuites
- alveoli
- circulatory systems
- the heart
- double circulatory system
- first, right ventricle pumps deoxygenated blood to lungs to take in oxygen
- second, after blood returns to heart left ventricle pumps oxygenated blood around all other organs of body.
- heart/pacemaker
- 1) resting heart rate controlled by group of cells in right atrium acting as a pacemaker
- 2) cells produce small electric impulses which spread to surrounding muscle cells
- 3) artificial pacemaker is often used to control heartbeat if natural one doesn't work properly.
- heart contracts to pump blood around the body
- 1)blood flows into 2 atria from vena cava and pulmonary artery
- 2)atria contract pushing blood into the ventricles
- 3)ventricles contract forcing blood into pulmonary artery and aorta and out of heart
- 4)blood flows to organs through arteries and returns through veins,
- 5)atria fills again and cycle repeats
- double circulatory system
- blood
- white blood cells(WBC)
- defend against infection
- 1)some change shape and engulf microorganism called phagocytosis
- 2)some produce antibodies to fight microorganisms as well as antitoxins
- have a nucleus
- defend against infection
- red blood cells(RBC)
- carry oxygen from lungs to cells in body
- shape=biconcave giving large surface area
- no nucleus
- red pigment called haemoglobin
- plasma
- RBC&WBC are platelets
- it carries things such as ...
- carbon dioxide
- urea
- hormones
- proteins
- antibodies & antitoxins
- platelets
- small fragments of cell
- no nucleus
- help blood to clot at a wound
- lack of them can cause excessive bleeding and bruising
- white blood cells(WBC)
- blood vessels
- capillaries
- arteries branch into cappilaries
- tiny
- carry blood really close to every cell to exchange substances with them
- permeable walls
- supply foos and oxygen and take away waste like co2
- usually one cell thick increasing rate of diffusion
- veins
- capillaries join to form veins.
- have a bigger lumen then arteries helping blood flow
- also have valves to help keep blood flowing in right direction
- rate of blood flow
- =volume of blood/number of minutes
- arteries
- 1) heart pumps blood at high pressure so artery walls are elastic and strong
- 2) walls are thick compared to size of hole in middle called lumen
- 3)contain thick layers of muscle to make them strong an elastic fibers to allow them to stretch and spring back
- capillaries
- the heart
- cardiovascular disease
- stents
- tubes inserted inside arteries keeping them open.
- a way of lowering risk of heart attack in people with CHD
- risk of complication during operation risk of infection in surgery
- risk of blood clots developing near stent
- called thrombosis
- statins
- reduce cholesterol in blood
- advantage
- reducing 'bad' cholesterol reduces risk of CHD and heart attacks
- can also increae amount of beneficial type of cholesterol in bloodstream
- disadvantage
- long-term drug must be taken regularly
- can have negative side-effects
- effect is not instant
- faulty heart valves
- 1)valves in heart can be damaged or weakened
- could cause valve to stiffen so it wont open properly
- could cause valve to leak allowing blood to flow in both directions
- 2)severe damage treated by replacing valve can be biological valves from other peopl/animals or mechanical valves
- 3)replacing valve much less drastic procedure then a whole hesrt transplant.
- 4)fitting artificial valves is still a major surgery and could cause blood clots
- 1)valves in heart can be damaged or weakened
- artificial blood
- 1)when someone loses alot of blood heart still pumps remaining red blood cells around
- 2)a blood substitute to replace the lost volume of blood
- 3)it would replace the function of the lost RBC's so there should be no need for a blood transfusion.
- stents
- health and disease
- diseases
- communicable
- can spread from person to person or between animals and people
- caused by bacteria, viruses, parasites and fungi
- non-communicable
- cannot spread between people or animals
- generally last for a long time and get worse over time
- communicable
- factors affecting health
- whether or not you have a good/balanced diet
- the amount of stress you are under
- your life situation; the access you have to medicine and facilities
- diseases
- risk factors for non-communicable diseases
- directly causing disease
- smoking
- during pregnancy as well as in general
- obesity
- excessive alcohol consumption
- exposure to certain radiation
- smoking
- costly
- human cost
- millions of people die from these diseases per year
- causes families to suffer as well as the individual
- financial cost
- NHS researching is very expensive
- families may have to move to adapt their home to help family member with a disease
- families income is reduced if the person with the disease worked or dies
- can affect the country's economy
- human cost
- directly causing disease
- cancer
- types of cancers
- benign
- 1)tumor grows until theres no more room
- 2)it stays in one place instead of attacking other tissues
- not normally dangerous or cancerous
- malignant
- 2)cells can break of & spread to other parts through the bloodstream
- 1)tumor grows & spreads to other tissus
- 3)they invade other tissues everywhere in body forming secondary tumors
- dangerous and fatal-they are cancers
- benign
- risk factors
- increase chance of some cancers
- lifestyle
- smoking
- obesity
- UV exposure
- viral infection
- genetics
- inherit faulty genes
- mutations in BRCA linked to likelihood of breast and ovarian cancer
- types of cancers
- transpiration & translocation
- phloem
- transport food substances made in leaves to rest of plant
- transport goes in both directions
- called translocation
- transport food substances made in leaves to rest of plant
- called translocation
- made of elongated living cells in end walls
- xylem
- made of dead cells joined together
- carry water&mineral ions from roots to stem&leaves
- movement of water from roots through xylem and out the leaves
- transpiration stream
- transpiration
- loss of water from plant
- evaporaion creates slight shortage of water in leaf.
- more water drawn up from roots- constant transpiration stream
- caused by evaporation& diffusion of water from plants surface
- factors affecting transpiration rate
- light intensity
- bright light= greater rate
- temperature
- warmer= faster rate
- air flow
- better= greater rate
- humidity
- drier air= faster rate
- light intensity
- guard cells
- kidney shaped &open and close stomata
- lots of water=turgid less water=flacid
- adapted for gas exchange controlling water loss within leaf
- phloem
- cell organisation
- malignant
- 2)cells can break of & spread to other parts through the bloodstream
- 1)tumor grows & spreads to other tissus
- 3)they invade other tissues everywhere in body forming secondary tumors
- dangerous and fatal-they are cancers
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