whole of biology paper 1 Flashcards
what are in both plant and animal cell and what are their functions?
- cell membrane (control what goes in and out of cell)
- mitochondria (respiration)
- nucleus (stores dna)
- ribosomes (proteinsynthesis)
- cytoplasm (reactions happen)
what else, not in an animal cell, is in a plant cell and what is their functions?
- cell wall (keeps structure)
- vacuole (cell sap)
- chloroplasts (where photosynthesis takes place)
what are in a bacterial cell and what are their functions?
- cell membrane (control what goes in and out of cell)
- cytoplasm (reactions happen)
- chromosomal dna
- flagella (movement)
- ribosomes (proteinsynthesis)
- cell wall (keep structure)
centimetre = ?
millimetre= ?
micrometer= ?
nanometre= ?
picometer= ?
centimetre = 1x10^-2
millimetre= 1x10^-3
micrometer= 1x10^-6
nanometre= 1x10^-9
picometer= 1x10^-12
what do different cells specialise into different things through?
differentiation
what is the equation for magnification?
image size= actual size x magnification size
fill in the blanks: (how enzymes work)
the __ fits onto the __ __ of an ___ making an __ __ __ which leads to the making of __
the substrate fits onto the active site of an enzyme making an enzyme substrate complex which leads to the making of products
how does temperature affect the enzyme activity?
when the temperature is low, the enzyme activity is low due to not enough energy
when the temperature gets higher, the enzyme activity reaches the optimum (the best)
when the temperature gets too hot, the enzyme activity decreases as the enzyme has denatured
how does pH affect enzyme activity?
if the pH is too low or too high, the enzyme activity decreases because the enzyme has denatured
if the pH reaches the optimum, the enzyme activity is at its best
what does an enzyme catalyst do to a reaction?
speeds up the reaction
how does substrate concentration affect enzyme activity?
as the substrate concentration increases, the enzyme activity also increases but soon it stops increasing due to the active site being filled up
fill in the blanks:
lipase breaks down __ into __/__ which are made in the __ and work in the __ __
lipase breaks down fats into fatty acids/glycerol which are made in the pancreas and work in the small intestine
fill in the blanks:
protease breaks down __ into __ __ which are made in the __ and work in the __ __
protease breaks down proteins into amino acids which are made in the pancreas and work in the small intestines
fill in the blanks:
amylase breaks down __ into __ which are made in the __ and work in the __ __
amylase breaks down starch into sugars which are made in the pancreas and work in the small intestines
define diffusion
diffusion is the movement of particles from a high concentration to a low concentration
define osmosis
osmosis is the movement of water particles from a high water concentration to a low water concentration through a semi-permeable membrane
define active transport
active transport is the movement across a membrane from a low to high concentration
what is cancer and what are the risk factors?
cancer is uncontrolled cell mutation
risk factors: smoking, diet, sun, unprotected sex
what are the uses of stem cells?
- treat parkinson’s disease
- organ failure
- bone and spinal injury
what is the method for stem cells?
- nuclei removed from egg cell
- nuclei from patients cell inserted into empty egg
- egg starts to develop into embryo
- stem cells removed from embryo and turned into new cells
what does the central nervous system consist of?
the brain and the spinal cord
what are the advantages and disadvantages of sexual and asexual reproduction?
sexual reproduction:
advantages- genetically diverse, disease less likely to infect the whole population
disadvantages- need a mate, longer reproduction cycle
asexual reproduction:
advantages- no mate required, quicker reproduction
disadvantages- genetically identical, disease will wipe out population
what are the processes of mitosis?
- interphase: dna gets replicated
- prophase: chromosomes pair up and condense
- metaphase: chromosomes meet up in the middle of the cell
- anaphase: chromosomes move apart to each end of the cell
- telophase: nucleus reforms
- cytokinesis: cytoplasm splits
what is the difference between mitosis and meiosis?
mitosis: produce 2 identical daughter cells, diploid, used for growth and repair
meiosis: produces 4 different daughter cells, haploid, used for sexual reproduction (gametes)
extracting dna from fruit (practical):
- mash up the fruit
- add salt water and detergents
- leave for 15 mins at 60 degrees
- filter
- add iced ethanol
- dna floats to the top
what are the complimentary bases for dna?
c and g
a and t
structure of dna:
- double helix structure into a chromosome which is in the nucleus
- sugar phosphate backbone
- 23 pairs, 46 in total, one from each parent
define gene
a stretch of dna which codes for a characteristic
define genome
all genes in a body
define gamete
a sex cell
define chromosome
bundled up dna
define alleles
different versions of genes
define dominant
only need one gene for this characteristic to pass down
define recessive
you need two identical genes for this characteristic to pass down
define homozygous
genes are the same
define heterozygous
genes are different
define genotype
what genes you have
define phenotype
what characteristics you have influenced by the environment, diet and exercise
what is selective breeding and what are the advantages and disadvantages?
selective breeding: breeding an animal for a particular characteristic
advantages: desired characteristic being made
disadvantages: may lead to health problems, lack of genetic diversity
define natural selection
individuals with characteristics which make them better suited to the environment and more likely to survive, reproduce and pass on their genes
what are the evidences for evolution?
- fossils which can show chnages and how animals are related
- bacteria
what is the definition of health?
the physical, mental and social well-being of a person (affected by diet, exercise, community)
what is a pathogen?
a microorganism that causes disease e.g. virus, bacteria, fungi, protist which can be spread through air, touch, blood
why does the immune system produce antibodies?
to recognise pathogens faster
what do phagocytes do?
they are a type of white blood cell which engulf the pathogens
what is a vaccination?
injection given which contains small amounts or dead pathogens which allows your immune system to develop antibodies so any further infections are dealt with quickly
what are the advantages and disadvantages of vaccination?
advantages: gives your body immunity, stops the spread of viruses
disadvantages: they don’t always work, your body can be immune to them, can cause painful side effects
what is a communicable disease?
a disease which can spread
what is a non-communicable disease?
a disease which cannot spread
what does it mean if you are susceptible to disease?
you have a disease which puts you at a higher risk of getting another disease
disease: cholera
type of pathogen:
effects:
method of spread:
disease: cholera
type of pathogen: bacteria
effects: diarrhoea
method of spread: water
disease: tuberculosis
type of pathogen:
effects:
method of spread:
disease: tuberculosis
type of pathogen: bacteria
effects: lung damage/coughing
method of spread: air
disease: chalara ash dieback
type of pathogen:
effects:
method of spread:
disease: chalara ash dieback
type of pathogen: fungi
effects: leaf loss
method of spread: air
disease: malaria
type of pathogen:
effects:
method of spread:
disease: malaria
type of pathogen: protists
effects: damage to blood
method of spread: mosquitos
disease: HIV
type of pathogen:
effects:
method of spread:
disease: HIV
type of pathogen: virus
effects: destroy white blood cells
method of spread: body fluids
disease: helicobacter
type of pathogen:
effects:
method of spread:
disease: helicobacter
type of pathogen: bacteria
effects: stomach ulcers
method of spread: oral transmissions
disease: ebola
type of pathogen:
effects:
method of spread:
disease: ebola
type of pathogen: virus
effects: fever
method of spread: bodily fluids
what do antibiotics do?
they kill bacteria, the non-resistant will die and the resistant will survive
what do new drugs need to be tested for?
- toxicity: how much can be taken before it becomes harmful
- efficiency: how well it works
- dose: how much can be taken
how do you work out BMI?
BMI= mass/height^2
what causes cardiovascular disease?
- fatty deposits building up in the coronary arteries (around the heart)
- leads to formation of blood clots which can block artery restricting oxygen to some cells leading them to die, if too many die it can lead to a heart attack
what are the risk factors of cardiovascular disease?
- smoking
- high blood pressure
- too much salt/fat in your diet
what does alcohol lead to?
- liver damage
- overweight
- cancer
what can smoking lead to?
- lung damage
- cancer
what things do you need to do in order to get an uncontaminated culture of bacteria?
- work near a flame
- work as quickly as possible
- flame your inoculating loop
how do you test for lipids/fats?
- add ethanol
- add to a test tube of distilled water, if present a white emulsion is formed on the surface
how do you test for starch?
- add iodine
- if present, it goes black/dark blue
how do you test for sugar?
- add benedict’s solution and heat for 2 minutes
- if it goes red, there is lots of sugar
- if it goes yellow/pale green, there is little sugar
how do you test for protein?
- add biuret solution
- if present, it goes purple
what are the four main sections of the brain and their roles?
- cerebral hemispheres: controls most of our senses, intelligence, personality
- cerebellum (back of the brain): controls balance, walking
- medulla oblongata (bottom of the brain): controls unconscious activities e.g. heart/breathing rate
- hypothalamus: regulates temperature and water balance
what are MRI’s and how are they used?
- MRI scanners use strong magnetic fields and radio waves to show details of brain structure and function.
- patients do a task and scientists can see which parts of the brain are active when the task is carried out.
what are CT scans and how are they used?
- patient lies on a bed which passes through a ring of equipment
- the ring takes a series of x-rays from different angles.
- these are processed by a computer to allow the doctors to see inside brains and other parts of the body.
what are PET scans and how are they used?
- they detect gamma rays
- they are used to detect high levels of metabolic reactions inside a person
- before going into the scanner the patient consumes the tracer which travels to any area of the body which has unusually high levels of metabolic reactions.
- PET scans are used to detect cancers.
what is the 5 kingdom system that we use to classify animals into?
- animals
- plants
- fungi
- prokaryotes
- protists
why do we use the 5 kingdom system?
to look at what organisms are related based on sequences in dna
what are the advantages and disadvantages of genetic modification and what is it?
genetic modification is to alter dna to change a characteristic
advantages:
- it is fast and very easy
- develop new medical treatment
disadvantages:
- very expensive
- can cause health problems
- can escape into environment causing other animals to be resistant
what is the process of bringing out new medication?
- drug is tested on human tissue
- tested on live animals
- tested on healthy humans
- tested on ill humans
- double blind trial
what is the job of a phagocyte
engulf pathogens
what is the job of lymphocytes?
produce antibodies
lytic pathway:
- uses host cell machinery
- dna replicates itself
- virus particles assemble
- the cell lyses (explodes open releasing all the viruses)
lysogenic pathway:
- viruses material becomes part of the cell DNA
- gets replicated as cell divides
what are the 6 key parts in an eye and what do they do?
- lens: let’s light into the eye and focuses it
- iris: coloured part of your eye
- pupil: hole in the middle which lets light in
- cornea: helps focus light
- retina: light sensitive and is filled with two types of cell (rod and cone)
- optic nerve: carries messages from the retina to the brain
what is a rod cell?
responsible for detecting differences in light intensity, works best in dim light
what is a cone cell?
responsible for detecting colour, works best in bright light
what do meristems do in plants?
found in root and shoot tips, can differentiate, stimulate growth
what are the benefits and problems of research with stem cells?
benefits:
- replace damaged cells in the body
- treat diseases which have no cure
problems:
- trying to remove stem cells may cause damage to embryo
- religious and ethical people mag disagree with this
- costs a lot of money
the brain and eye diagrams labelled
do this on paper
what is the process of a normal action in the nervous system?
(seriouslycomemineeatchicken)
electrical impulses pass through
1. stimulus
2. receptor
3. sensory neuron
4. CNS
5. motor neuron
6. effector
7. carries out the response
what is the process of a reflex action in the nervous system which helps prevent harm?
electrical impulses pass through
1. stimulus
2. receptor
3. sensory neuron
4. relay neuron
5. effector
6. carries out response
why is the reflex action faster than a normal action?
because it doesn’t pass through the central nervous system
what is a synapse
the gap between two neurons
what is the process for the transmission across a synapse?
- information travels across neurons as electrical impulses
- when it reaches the end of a neuron it triggers the release of a neurotransmitter
- this moves across the synapses by diffusion and binds to the receptors on the surface of the next neutrons
what is an effector?
which ever muscle carries out the response
what is a receptor?
a thing that detects a change
what does a myelin sheath do?
prevents the loss of electrical impulses
what causes short sightedness and how can it be treated?
the eyeball being elongated - so that the distance between the lens and the retina is too great.
the lens being too thick and curved - so that light is focused in front of the retina.
Short-sightedness can be corrected by placing a concave lens in front of the eye.
what causes longsightedness and what causes it?
the eyeball being too short - so the distance between the lens and retina is too small
a loss of elasticity in the lens - meaning it cannot become thick enough to focus (which is often age-related)
As a result, the lens focuses light behind the retina instead of onto it. Long-sightedness is corrected by putting a convex lens in front of the eye
what determines the amount of brain damage?
the force of impact
the size or shape of the object hitting the skull
the position the object hits the skull
the time it takes for treatment
what is the problem with treating brain damage?
the brain is so delicate that it might cause more damage and affect the persons quality of life
what type of reaction is photosynthesis and why?
what is the word equation for photosynthesis?
- endothermic reaction as heat is entering the chloroplast by light
carbon dioxide + water —> glucose + oxygen
what are the complimentary base pairs joined by?
weak hydrogen bonds
how many dna codes make up one amino acid?
3
during dna extraction practical, why do you add ice cold ethanol
to precipitate the dna
what does blood carry?
oxygen and glucose for respiration
what are 3 treatments for cardiovascular disease?
- improve lifestyle
- medication (statins) which help to reduce blood glucose
- surgery: stents are added to widen the blood vessel, bypass which provides alternative root for the blood to travel around the blockages
how do things develop resistance to antibiotics?
mutation- a feature that makes bacteria resistant
the bacteria survives, reproduces and passes on their genes to their offspring and the normal ones die
caused by not finishing the course
