Bio- Topic 1

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

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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

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Cell diagrams-

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Cell diagrams-

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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

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Test for starch+sugar

Starch= Iodine

yellow/brown to blue/black

Sugar= Benedicts Solution

blue to brick red

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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

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The Effect of temp' against the rate of amylase ac


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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)

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Chem reactions within cells are controlled by enzymes(proteins)

>speed up reactions

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Chem reactions within cells are controlled by enzymes(proteins)

>speed up reactions

Denature- proteins lose structure by ext stress (strong acid base/temp'...)

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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                

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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

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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

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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.

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Enduces emulsification which speeds up reaction due to increase surface area for enzymes

Produced+ Stored= Liver + Gall Bladder

Takes effect? Small intestine


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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


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Adaptations of a leaf for photosynthesis

External+ Internal:

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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

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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

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Anaerobic Respiration


Glucose > Lactic Acid + (some) energy

Plants and Yeast- 

Glucose . Ethanol + CO2 + (some) energy




No oxygen

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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)

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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

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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

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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

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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

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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.

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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?
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 

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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. 

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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 

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