What are living things made from one cell called?
What is the function of the nucleus?
-it controls the activitys of cell and contains generic information
What's the difference between an animal and plant cell?
Animal cells do not contain a vacuole and cell wall
What is a nerve cell?
A specialised cell that transmits electrical nerve impulses.
What are some examples of specialised cells?
Root hair cell, white. Blood cells, sperm cells
How are cells organised?
What's the function of the circulatory system?
To transport substances around the body, includes blood vessels and heart
" " " reproductive system?
To produce offspring
" " " excretory system?
To remove unwanted waste from the body
" " " respiration system?
To obtain oxygen and remove carbon dioxide
" " " digestive system
To break down large insoluble molecules to small soluble molecules to be absorbed into the blood
What is growth?
The permanent increase in size as an organism develops
What are stem cells?
Undifferentiated cell,s that have the ability to produce new cells
What are stem cells used for?
To replace burned skin, medicines
What are embryonic stem cells?
Stem cells that can become any cells in the body
What are tissue stem cells?
Cells that can only do one job in the body
What do stem cells do?
Either renew or differentiate
What are enzymes?
Proteins that act as a biological catalyst, found in living organisms
What is the active space?
The place in which which the substrate fits
What is optimum temperature
The temperature in which the enzymes perform at their best
How does temperature effect enzymes?
As temp increases so th enzyme activity until you reach optimum temperature or ph and then the activity decreases
Why does this decrease?
Because the enzyme becomes denatured
What is the equation for respiration?
Glucose +oxygen --> carbon dioxide + water + energy
What is aerobic respiration?
Where oxygen is present, it gets oxygen to the working muscles efficiantly and prevents oxygen dept
Why do we respire?
To release energy, to make contract and move and it keeps us warm
What is anaerobic respiration ?
When we respire with little oxygen, we can't break down all the glucos into water and co2 so we make lactic acid and go into oxygen dept making our muscles ache
What is diffusion?
The spreading of particles of a gas or solution resulting in net movement from a high concentration to a low concentration due to kinetic energy.
What is osmosis?
The movement of water particles from a high concentration to a low concentration through a semi permanent membrane.
What happens if the cells gains water?
It becomes turgid, the vacuole swells
What happens if the cell looses water?
It becomes flaccid and shrinks
What is an example of a semi permeable membrane?
What is ecotourism?
It encourages visitors to a country,, an impact that tourism has on a naturally beautiful environment
What is population explosion?
The human population is growing rapidly, more waste is being produced, humans reduce the land left for plants and animals, raw materials including not renewable resources are being used up
What is deforestation?
Cutting down trees and clearing forest areas
What are the benefits of deforestation?
It provides fuels for burning, palm oil and it makes space for housing a living space
What are the disadvantages of deforestation?
It destroys animals habitats it increases CO2 by burning rotting and reducing photosynthesis
What is sustainable development?
Conserving and using natural resources wisely, being energy efficiant and only using what we need
What Is intensive farming?
Producing high yeild crops
How do farmers achieve this?
By keeping animals inside warm cages etc so they reduce movement and loss of heat or by using fertilisers and pesticides on crops
Maximum yeild cheap, little space needed, no food waste
Heating and lighting is required, risk of disease and it is in natural
What is organic farming?
Bans chemical inputs has less of a harmful effect on the environment, but they often produce less more expensive food.
Can be sold for more money, natural, less food need to be supplied to animals
Less food or crops produced, more land needed, vulnerability to predation
What are the three main water pollutants?
Oil, sewage and chemical waste.
Describe the process of oil pollution:
It sits on the sea, and gets into the Eco system, it kills wild life and birds, gets carried to shore, sprayed with detergent, removed with suction on ships, effects fishing and tourism industries
Descirbe the process of sewage pollution :
Gets decomposed by bacteria, which multiplies and uses up all oxygen, fish will die to to lack of oxygen,
What is eutrophication?
Fertilisers cause a green bloom on top of the lake- algae grow- fish can't access oxygen
How is chemical waste formed?
Form industries and factories, kills wildlife and gets into food chain
What's a biological control?
When you us something living to control something else
What is digestion?
The break down of large insoluble molecules into small soluble molecules so they can be absorbed into the blood, e.g carbohydrates proteins and fats.
What does amylase do and where is it produced?
Made in salivary gland, small intestine and pancrease turns starch into sugars
What dies protease produces and what does it do?
Made in stomach small intestine and pancrease turns proteins into aminio acids
What does lipase do and where is it produced?
In pancrease and small intestine turns lipids into fatty acids and glycerol
What does carbohydrase do?
Turns carbohydrates into starch
What is the oesophagus?
Also called the gullet, takes food from mouth to stomach
What does the liver do?
Produces bile which neutralises stomach acid
What is the gall bladder?
Stores the bile
What does the small intestine do?
Produces enzymes and nutrients and absorbed into blood
What does the large intestine do?
Excess water is absorbed from the food
What is mastication?
Describes the way food is chewed up
The lap that covers the windpipe when swallowing
What is peristalsis?
Mucle contractions that push food down through the digestive system
Large fat droplets are broken down into small fat droplets
What is photosynthesise?
Where the plant takes in co2 and converts it into oxygen
Carbon dioxide + water --> glucose + oxygen
How is the leaf adapted for photosynthesis?
Chrlorophyll; allows plant to absorb sunlight
Veins to carry water
Large surface area
What factors effect photosynthesis?
What happens the the glucose produced by photosynthesis?
Used by cells of plant, or converted into starch for storage
What's the test for starch ?
Iodine-parts with chlorophyll would turn blue/black
What are the two tissue processes used in transpiration?
Xylem and phloem
What does a food chain show us?
How energy is passed from one organism to another
What is a population ?
All the organisms in a species in a given area
Plants that make their own food
Eats plants and animals
What are pyramids of numbers?
How many of the organisms their are, plant goes at the bottom
What are pyramids of biomass?
The amount of material that living things a made from. The wider the bar the more biomass there is, flows down a food chain, some is lost at each stage
Why is energy lost in food chains?
The % of energy that is passed on is lost at each stage due to growth, reproduction, movement and respiration.
How can you reduce energy loss?
Restricting movement, providing warm surroundings , shortening the food chain.
What is the balanced cycle of decomposition?
Materials moved from environment <--> materials returned to environment
What is decomposition?
Described the process which dead plants and animals and waste are broken down by micro organisms so materials can be retuned to the environment
What are detritus feeders?
Feed on dead plant and animal materials
What are decomposes?
Digest dead plants and animals to release substances plants need to grow.
What is decomposition used in?
Nature to get a contsant supply of materials
Sewage treatment-breaking down waster
Compost heaps-breaking down plant material
What. Are the main stages in the carbon cycle?
Feeding photosynthesis decay respiration
What part do microbes play in the carbon cycle?
They feed on dead plants and animals so the nutrition and co2 can be returned back into the land
Extra exam style questions:
What is a possible environmental disadvantages to the continuous use if an insecticide near the lake ?
Resistance and immunity to the insecticide due to a mutation leading to less biodiversity
What are two substances needed for active transport to take place?
What is an advantage of active transport?
Helps plants gain the minerals they need