Science Flashcards
What effect does tar have on the cilia
It causes the cilia to stop working and eventually die
Explain why muscles need more blood during exercise
Muscles require more energy during exercise. Additional oxygen and glucose are needed to release the energy. Blood flow increases to supply these to muscles faster. Respiration also increases to allow more oxygen to be transported to the muscles.
what are dangers of being too underweight?
Lack of energy, poor immune system, lack of minerals and vitamins
What are dangers of being too overweight?
Stroke, heart disease, type 2 diabetes, cancer
What are carbs
Main source of energy in the diet
What are proteins?
used for the growth and repairing of the body
What are vitamins and minerals
Important for the function and development of the body example-vegetables
What does fibre do
It bulks out food to keep it moving through the digestive system example-oats
What are lipids
help control what goes in and out of your cells and store energy
How do you test for starch
Iodine solution- turns black
How do you test for sugar
Benedict’s solution- turns orange/red
How do you test for lipids
Ethanol- turns cloudy
How do you test for protein
Biuret solution- turns purple
What are enzymes
proteins that speed up (catalyse) solutions. They are in the digestive system and break down starch into glucose
What do digestive enzymes do
Break down substances into new substances without being changed in the reaction
What chemical in tobacco makes it addictive?
Nicotine
What are atoms
Particles far too small to see even with a microscope. Everything is made out of atoms
What is an element?
A substance that is only made up of one type of atom like oxygen
What is a compound
A substance that is made up of 2 or more types of elements which are chemically bonded like H20
What is a mixture
A substance that is made up of 2 or more types of compounds or elements that can be physically seperated, no chemical bond
What carries glucose from the intestine to other parts of your body
blood
What is glucose?
A type of sugar you get from foods you eat and your body uses for energy
What does saliva contain that causes starch to change
amylase enzymes
What are the properties of a metal?
High melting and boiling points, good conductors, shiny, malleable, sonorous, hard and strong, high density
What is the structure of an atom
All atoms have a nucleus. Inside the nucleus are the protons and neutrons and in the outer shells are the electrons
what do horizontal rows on the periodic table tell you
called periods- tell you how many shells an element has
Which period is the most reactive
The last one, period 7
What does the group number tell you
number of electrons in the outer shell
What are group 7 elements also called
The halogens, they are reactive, have 7 shells in the outer shell, diatomic and non metals
What is the proton/atomic number
tells us the total number of electrons. found under name of the element
How do you draw the electronic structure of an element
. write symbol
. find the period the element is in and draw the shells
. start drawing crosses to draw electrons. 1st shell has 2
. find group the element is in to fins number of electrons in the outer shell
What is a force
A strength/energy as an attribute of physical action of movement. Can be a push, pull or twist. Can change an object’s speed, direction or shape. Forces are measured in newtons.
What is upthrust
Upward force that a liquid or gas exerts on a body in floating it
What is friction
Force that acts between 2 surfaces that are touching. It opposes their movement and acts as an invisible brake
What is weight?
The mass a person weighs multiplied by the gravitational pull of an area. Measured in newtons
What is static energy?
imbalance of electric charges within or on the surface of a material
What is an electric field
physical field surrounding electrical charged particles. Created by a charged object
What is energy?
The flow of charged particles
What is current
measure of electrons flowing through a circuit. The more charge that flows, the bigger the current. Measured using an ammeter
What is potential difference/voltage?
The push provided by a cell or battery to make charges move. measured in volts with a voltmeter
what is resistance
Components do different jobs in an electric circuit. Each circuit component has a different resistance which tells you how easy/ difficult it is for the charges to pass through the component. It is measured in ohms. Affected by material of wire, how thick and long the wire is and the temperature of the wire
What is a magnetic field
the region around a magnetic material
What is a permanent magnet
A magnet that has its own magnetic field
What is an electromagnet
A temporary magnet that can be turned off by turning the current off. it is a soft metal core made into a magnet by the passage of electric current through a coil surrounding it. To increase the strength you can increase the number of coils, increase size of current and use materials that can be easily magnestised and demagnetised
what is the word equation for photosynthesis
Carbon dioxide+water ARROW glucose + oxygen
Where does photosynthesis occur?
In the chloroplasts in the leaf cells
why are leaves and stems green
the contain the green pigment chlorophyll
What is a solution?
A mixture in which 1 or more solutes is dissolved in a solvent
What is a solvent?
A substance in which something is dissolved
What is a solute
a substance that can be dissolved
What happens when sugar dissolves?
Water particles surround each sugar particle. The sugar particles can mix with the liquid. They are arranged randomly and move around
How do you increase the rate that a solute dissolves
stir the mixture, increase temp of solvent, crush solute
What is filtration used for?
Used to sepearte a liquid and an insoluble solid
What is evaporation used for?
Used to remove the solute from the solution. It is used when the solute dissolves in the liquid and filtration can’t be used. It gets rid of the solvent
What is dissolving
a process where solute particles disperse throughout the solvent
What si energy
the potentiual to do work. it cannot be created or destroyed, only transfered betweenn differnet energy stores. It is measured in joules.
What are different types of energy stores?
.Kinetic energy- movement
. Gravitational potential energy- potential to fall due to gravity
. thermal energy- heat
. Elastic potential energy- stretching and compressing
What is temperature?
how hot or cold something is
What is fuel?
Materials that are burnt to produce a large amount of heat energy e.g. coal
What are fossil fuels?
Fuels produced naturally, not infinite, release C02, cheap, readily available
What do greenhouse gases do?
Trap heat in atmosphere
What is stationary?
An object that is not moving and has speed 0m/s
What is speed?
A measure of how quickly a distance is covered er unit time
What is the equation for speed
speed= distance/time
What is the thinking distance?
How far the car travels in the time it takes for the driver to press the brakes after realising they need to stop
What is the braking distance?
How far the car travels after the driver has applied the break
What is the equation for the stopping distance?
Stopping distance= thinking distance+ braking distance
What do crumple zones do?
Increase the time taken for the car to stop meaning that the impact force is less
What happens if the volume is smaller?
The pressure is higher and thereofre there are more collisions between molecules and the walls of the container
What happens when a gas cools down?
molecules move more slowly and the pressure decreases
What happens when a gas heats up?
molecules move more quickly and there are more collisions and the pressure increases
How does the less air pressure going down on you affect you?
The higher you go. Atomspheric pressure changes with altitude, the higher you go the lower the weight of the air above you and the lower the atmospheric pressure
what happens the deeper you go
the greater the weight of the pressure above and the greater the liquid pressure
What force is produced by liquid pressure?
Upthrust, the force that keeps things afloat. It acts on any object that is floating or submerged in a liquid
How can you make the gas pressure increase?
Increase temperture, decrease volume
How can you make the gas temperature decrease?
Decrease temperature, increase volume
What is atmospheric pressure?
caused by air particles colliding with a surface. As height increases there is always less air above a surface than at a lower height. Atmospheric pressure decreases as we go higher up
What is pressure?
A measure of how much force is applied over a certain area
What is the equation for pressure?
Pressure= force/ area
why is renewable energy good?
Doesn’t run out because it is naturally plenished, environmentally friendly, safe
What is nuclear energy?
Energy released from the nucleus. It doesn’t release crbon dioxide or sulfure dioxide and it produces a lot of energy but it is hazardous and non renewable
What do animals compete for?
Water, food, space, mates
what do plants compete for?
Minerals, water, space, light
What is competition?
interaction between organisms after the same limited resources
What are adaptations of a cactus?
. Thick waxy skin to prevent water loss
. Large fleshy stems to store water
. Spikes to prevent fleshy stem from being eaten
. Shallow widespread roots to absorb rain and nutrients/minerals
What is the predator prey relationship?
It shows how the population of the prey and the predator are linked. When the population of the prey is high, the population of the predators increases as they now have a larger food supply. However, if there is a large predator population, the population of the prey decreases. Now that there is less prey, the predators have a smaller food supply so their population decreases. As a result of this, the prey relationship increases again and the process repeats
What are structural adaptations?
Physical features that allow an organism to be succesful in its envuronment
What are functional adaptations?
special biological processes an organsims body might perform to make it well suited to its environment like sweating
What are behavioural adaptations?
Actions an organism might perform to make it well suited to its enviroment like hibernation and migration
What are the 4 steps in plant reproduction?
Pollination, fertilisation, seed dispersal, germination
What is pollination
transfer of pollen from the anther to the stigma. It can happen using wind or insects
What is the carpel?
Female part of the flower
What is the stamen
male part of the flower
What is the ovule
female gamete
What part of the flower holds the stigma
the style
What part of the flower catches pollen
the stigma
What does the anther do
produces pollen
What does the sepal do
special leaf that protects unopened buds
What happens when you rub a balloon on your jumper
electrons are transferred from the jumper to the balloon. The balloon now has an overall negative charge and the jumper has an overall positive charge. They now attract
How does the current change around a circuit
the current is the same everywhere in series
How does the p.d/voltage change around the circuit
it is the same everywhere in parallel
food tests, electricity, photosynthesis, anaerobic, aerobic, adaptation, variation, acids and metals, speed, distance
What is the word equation for photosynthesis
carbon dioxide+water ARROW glucose + oxygen
Where does photosynthesis take place?
In the chloroplasts in the leaf cells
what is photosynthesis
most plants make their own food. They do this using gas in the air and water absorbed by the roots in the soil to create sugar. Energy is needed to do this. The source of energy in photosynthesis is sunlight. The nuclear store of energy in the sun is transfered to a chemical store of energy in the plant by light. energy is transfered to the chlorophyll in the chloproplasts of the leaf cells.
How does water get into a plant
Water is diffused into the root hair cells and then transported around the plant in xylem tubes.
Why do plants have a large surface area
to absorb as much light as possible
How do gases get into and out of a leaf
Through tiny holes on the bottom surface of a leaf called stomata. They allow gases to diffuse in and out of a leaf. Carbon dioxide diffuses in and oxygen and water vapour diffuse out. Stomata are open and closed by guard cells. Guard cells open them in the day and close them in the night.
what are the 2 layers of the leaf
palisade layer- packed with chloroplasts, where most photosynthesis occurs
spongy layer- has air spaces allowing gases to diffuse in and out of the leaf
what minerals do plants need
magnesium, potassium, phosphates, nitrates
Which direction do magnetic field lines travel
from the north to south pole
