Bio- Topic 1
- Created by: Craig White
- Created on: 30-04-14 19:58
Characteristics of life+ the variety of living org
Population- All the organisms of a particular species living in an eco-system at a particular time.
Eco system- A distinct sef-supporting system of organisms interacting with eachother and their physical environment
Community- All the pop. of living organisms living in an eco system at a particular time.
Quadrats- Square grid, sampling abundance and distrubtion, X+Y, Scale, random no. generator
Ecology
Ecology:
Movement- Change position: move their structure to more favourable conditions
Respiration- Chem process in which glucose is broken down>releases energy +CO2 +H20 (requires oxygen)
Sensitivity- Detecting and responding to changes in the environment
Control- Maintenece of a constant internal environment such as body water content + temp'- homeostasis
Growth- Permenant increase in body size+ dry mass
Reproduction- The production of offspring to continue a species
Excretion- The removal of waste that has been produced from chem reactions in the body
Nutrition- The taking in of substances to make food
Cells
Cell diagrams-
Cells
Cell diagrams-
Cells and Molecules
Mitochondria- The site of aerobic respiration, here glucose is broken down in the presence of oxygen to release energy.
Chloroplasts- Where photosynthesis happens. Light is absorbed by the pigment chlorophyll and this energy is used to make food.
Cell Membrane- Partially permeable membrane( allows some through)-holds cells together
Vacuole- Contains cell sap(sugars+mineral ions) when full it supports.
Nucleus- instructions needed to control the activities (in chromosomes)
Cytoplasm- Contains organelles+ enzymes taht catalyse many of the reactions
Cell wall- made out of cellulose (carbs), supports the cell and define shapes
Test for starch+sugar
Starch= Iodine
yellow/brown to blue/black
Sugar= Benedicts Solution
blue to brick red
Diffusion/Osmosis/Active transport
Diff= net movement of particles from high to low (down a concentration grad)
Effects-Temp', Ratio of surface area to vol of water, % change=chnge in mass/startingx100
Osmosis= net movement of water from dilute solutions to a more concentrated solution across a partially permeable membrane. >doesn't require energy
Active Transport= Low to high + needs energy for respiration
The Effect of temp' against the rate of amylase ac
Graph-
Carbs/Lipids/Proteins
Carbs-simple sugars,carbo-hydro-oxy,energy,5%, glucose fructose
(simp sugars+starch/glycogen)
Lipids-fatty acids,glycerol molecule,carbo-hydro-oxy,long t ener+cell mem, 10%,
(fats +oils)
Proteins- amino acids, carbo- hydro-oxy-nitro,muscle-immune-growth-enzymes, 18%
(active transport)
Enzymes
Chem reactions within cells are controlled by enzymes(proteins)
>speed up reactions
Enzymes
Chem reactions within cells are controlled by enzymes(proteins)
>speed up reactions
Denature- proteins lose structure by ext stress (strong acid base/temp'...)
Nutrition and Respiration
Nutrient Source Function
Carb fruit,veg,milk,bread,potat Fuel for cells (energy)
Prot meat,fish,cheese,eggs Growth+repair+enzymes
Lip meat,butter,cheese,oily fish 10%bod mass+cell struct+energy+insulation
Fibre Cereal contents moving
Water Water Everything
A liver oils,butter,marg,carr eye retina
C fruit,veg fibres+resistance to disease
D liver oils,sunlight Growing bones
Calc Dairy,fish teeth+ bones
Iron red meats haemoglobin+ helps carry oxygen
Villi
Folded Surface- increased surface area to vol ratio
Good blood supply- each villus has a blood capillary within them making absorption faster
Short diffusion distance- only one cell thick
Peristalsis
1) Rhythmic muscle contractions of the stomach+ intestine moves food along the alimentary canal
2) Allows movement of food and does not depend on gravity
Key Words
Absorption- Passage of digested food molecules into the blood
Assimilation- Converting food moelcules to other molecules for us ein body
Ingestion- Taking food in through mouth
Digestion- Chemical+Mechanical breakdown of large food molecules into smaller soluble ones.
Bile
Enduces emulsification which speeds up reaction due to increase surface area for enzymes
Produced+ Stored= Liver + Gall Bladder
Takes effect? Small intestine
NEUTRALISES STOMACH ACIDS
Nutrition in Plants
Testing for starch-
Good for storing carbs- a)not soluble/doesn't affect osmosis b)compact and c)broken down easily/converted to glucose for resp> Can't just add iodine because a)cannot get in b) green pigment masks colour change
Leaf in light- Whole leaf/blueblack/light/photosynthesise
Leaf in dark- No colour change/no starch/starch is used as energy source/not replaced
Variegated Leaf- No chlorophyll/only starch on green part (chloro)
Paper Stencil Leaf- Majority/blueblack/strips of no starch-no light
YOU NEED LIGHT FOR PHOTOSYNTHESIS AND CHLOROPHYLL
Adaptations of a leaf for photosynthesis
External+ Internal:
Ion deficiencys
Leaves turn yellow>>>Magnesium>>>Part of chlorophyll molecule
Stunted growth+older leaves turn yellow>>>Nitrate>>>amino acids,proteins etc
Poor root growth+younger leaves turn purple>>>Phosphate>>> DNA, part of cell mem
Leaves turn yellow with dead spots>>> Potassium>>> enzymes+respiration
Photosynthesis
Photosynthesis Equation
Carbon dioxide + Water > glucose + oxygen
CO2 +H2O > C6 H12 O6 + 6O2
Requirements- Light, CO2,Chlorophyll
Light energy > Chem energy (released in resp)
Factors that affect- Water, CO2, Light ,colour,chloropyll
Anaerobic Respiration
Animals-
Glucose > Lactic Acid + (some) energy
Plants and Yeast-
Glucose . Ethanol + CO2 + (some) energy
Where?
Cytoplasm
When?
No oxygen
Gas Exchange in Plants
Particles move from hight to low(diffusion)
A gas that enters a cell does so because- it wants to move to an area of low concen
CO2- Photosythesis(inside big) Respiration(Outside small)
Oxygen- Photosynthesis(Outside big) Respiration(Inside small)
Gas Exchange in Humans
The respiratory System-
1) Air enters through nostrils/mouth
2) Air travels down the windpipe (trachea)
3)Trachea branches off into the bronchi
4)Each bronchus branches into many bronchi
5)At the end of bronchioles gas moves in/out of alvioli (air sacks)
6)Gas dissolves in the lining and diffuses across capillaries
7)Capillaries transport the blood around the body
Adapted?- Cartilidge prevents airways from collapsing / ensure is clean- have cilia +mucus
Pleural Membrane- stops surface from sticking
Transport in Humans
Plasma- Liquid part of the blood> carries blood cells around the body
RBC- Bioconcave>disc like>no nucleus> transport oxygen -haemoglobin
WBC(lymph)- Same size as RBC>nucleus>produce antibodies to destroy pathogens
WBC (phago)- Larger cells>engulf bacteria
Platelets- Smallest cells> releases chemicals to make blood clot
How do phagocytes work?1) identifys pathogen 2)changes shape to surround 3)pathoghen is ingested(vacuole) 4)Digestive enzymes break it down
Antibodies- Soluble proteins that destroy pathogens
Antigens- Markers on pathogens that enable antibodies to recognise them
Lymphocytes- White blood cells that produce antibodies
Smoking
Affects the respiratory system.
Damage> Nicotine>Tar>Carbon Monoxide
Normal Alveoulus> Elastic, More surface area for gas exchange, short diffusion pathway
Smokers Alveoulus> Not elastic>less surface area> diffusion pathway blocked
Types of blood vessels
Blood direction- Blood pressure- Wall structure- Wall thickness- Internal diameter- valves?
Arteries- Away from the heart, high blood pressure,muscle/elastic/thick/tissue,very thick,small,no
Capillaries- Arteries to the veins, high blood pressure,one cell thick, thin,small,no
Veins- towards the heart,low,muscle/thin/elastic/tissue,thin,medium,yes
The Cardiac Cycle
Blood enters atria, but cannot go through ventriclesbecause AV valves are closed. The walls of atria contract raising pressure of the blood in the atria which forces the AV valves open. Blood passes through into the ventricles. When the ventricles are full, they contract. This increases the pressure of the blood in the ventricles which closes the AV valves. This stops the blood returing to the atria. The ventricles continue to contract and pressure increases, forcing open the semi-lunar valves at the bas eof the aorta + pulmonary artery. Blood is ejected into these 2 arteries. Pulmonary carries blood tot he lungs> The aorta has branches that carry blood to all other parts of the body. As the ventricles empty, higher pressure in the aorta and pulmonary artery close the valves in these blood vessels. The cycle continues.
Transport in Plants
Where abouts is water lost? The stoma/leaves
Water is important for mineral transport and photosynthesis
What vessels transport water and minerals in plants? Xylem
How are they adapted?
1)Lignin
2)Dead cells
3)Impermeable to water
Water is taken in by osmosis
Mineral Ions are taken in by active transport
Mineral ions are transported dissolved in the water
Transpiration
Transpiration is the loss of water (evaporation) vapour from the leaves
Transpiration causes water to be transported up the Xylem in the stem and roots in a continous flow= TRANSPIRATION SYSTEM
As welll as supplying water to the leaf for photosynthesis and carrying dissolved material ions in the transpiration stream keeps a plant trugid (upright), and allows evaporation from the leaf surface which cool the plant.
Factors that affect transpiration
Temperature- speeds up the reaction- Particles move faster increasing the rate of evap
Light- speeds up the rate- Stomata opens- increased rate
Wind- speeds up the rate- water around leaf is blown off
Related discussions on The Student Room
- Grade Growth Chronicles | From C's to A's (23-24) »
- What should I choose bio or math »
- Is it too late? »
- False topic list for Bio exam - what to do ? »
- AQA A-level Psychology Paper 3 (7182/3) - 5th June 2023 [Exam Chat] »
- Why is a 2:1 'good' when it's technically average? »
- Wrong topic list for UCAS end of years mocks »
- Revision Struggles?! Join the 2023 TSR All Day Revision Thread! »
- Medicine entry »
- Time off revising A Levels »
Comments
No comments have yet been made