Biology Flashcards
function of the cytoplasm
site of chemical reactions
function of the cell membrane
controls what substances go in and out of the cell
function of the mitochondria
site of aerobic respiration
releasing energy
function of the ribosomes
site of protein synthesis
function of the cell wall
strengthens the cell
provides support
function of the chloroplasts
contains chlorophyll
site of photosynthesis
function of the permanent vacuole
contains cell sap to keep plant cells rigid
provides support
3 differences between animal and plant celssa
plant cells have chloroplasts, permanent vacuole and cellulose cell wall
animal cells do not
what substances make up a plants cell walls?
cellulose
differences between prokaryotes and eukaryotes
prokaryotes do not have a nucleus.
eukaryotes do.
prokaryotes are bacteria and viruses
eukaryotes are animal and plant cells
one organism that is prokaryotic
bacteria
what is the name of the extra small DNA rings found in some prokaryotes?
plasmids
the use of tail in sperm cells
to swim and move around (to reach the egg)
why do sperm cells have lots of mitochondria?
to provide lots of energy for swimming
root hair cells have lots of mitochondria to release energy. what is the energy used for?
active transport of mineral ions into root hair cells
which specialised cell in plants make up the tissue for transporting water?
xylem cells
name the substance found in xylem cells that alloe the cells to withstand high water pressure
lignin
the difference in structure between xylem and phloem
Xylem: dead, hollow tube, has lignin
Phloem: living, has sieve plates, no lignin
Define Diffusion
movement of particles from an area of HIGH TO LOW concentration
3 factors that affect the rate of diffusion
concentration gradient
temperature
surface area
a substance that diffuses into our cells for use
oxygen
glucose
explain why higher temperature results in faster diffusion
particles have more kinetic energy, so move around more
name a substance that diffuses out of our cells to be removed
carbon dioxide
urea
osmosis
movement of water from a DILUTE to a CONCENTRATED solution through a partially permeable membrane
if a cell is in a hypertonic solution, water will (enter or leave) the cell
leave
if a cell is in a hypotonic solution, water will (enter or leave) the cell
enter
animal cells burst in hypotonic solutions because
no cell wall
active transport
movement of particles from a LOW TO A HIGH concentration
requires energy
a gene is…
a short section of DNA that codes for a protein/ controls a characteristic
a chromosome is..
structures in the nucleus that carry genes
how many chromosomes are in one human body cell
46
chromosome are arranged in how many pairs in a human body cell
23
2 key importances of mitosis
growth
repaie
the first stage of the cell cycle
cell size increases
DNA and organelles replicate
second stage of the cell cycle (mitosis)
nucleus divides
the third stage of the cell cycle
cytoplasm and cell membrane divides into two genetically identical daughter cells
differentiation
the process where a cell becomes specialised/adapted to perform specific functions
stem cell
undifferentiated cell with the potential to become specialised
adult stem cells
stem cells that can only differentiate into a specific type of cell
where does differentiation occur in plants?
root tip
shoot tip
embryonic stem cells
stem cells from an early embryo that can differentiate into all cell types
define tissue
a group of cells with a similar structure working together for a specific function
define organ
a group of tissues working together for a specific function
reorder in increasing size order:
organ
cell
tissue
organ system
organism
cell < tissue < organ < organ system <organism
the tube that carries food from the mouth to the stomach is
oesophagus
the function of the salivary glands
produce digestive system enzymes (amylase)
the function of the stomach
releases digestive enzymes to digest food
the function of the liver
produces bile
the function of the small intestine
digest food and absorb nutrients from digested food
the function of the large intestine
absorb water from digested food
the function of the pancreas
produces/releases digestive enzymes
the function of the gall bladder
store bile before release into small intestine
what is the positive result for the starch test
starch turns iodine solution from brown-red to blue-black
what is the positive result for sugars
Benedict’s solution turn from clear blue to brick red
what is the positive result for proteins
biuret turns from blue to lilac
what is the positive result for lipids
cloudy white layer
a risk of doing food tests
ethanol is flammable
biuret is corrosive
define a catalyst
a substance that speeds up chemical reactions but doesn’t get used up
define enzyme
biological catalysts that speed up chemical reactions
enzymes are..
proteins
define digestion
breakdown of large insoluble molecules into smaller soluble substances
the type of enzyme that digests carbohydrates
carbohydrases
the enzyme that digests starch
amylase
the product of the breakdown of starch
simple sugars
glucose)
the type of enzyme that digests proteins
proteases
the product that breaks down proteins
amino acids
the type of enzyme that digests lipids
lipases
the products of the breakdown of lipids
glycerol and fatty acids
which organs produce amylase
salivary glands
small intestine
pancreas
which organs produce proteases
stomach
pancreas
small intestine
which organs produce lipases
pancreas and small intestine
what is plasma in the blood
yellow liquid that carries blood cells
proteins and dissolves substances around the body
function of platelets
blood clotting
where does starch digestion occur
mouth
small intestine
where does lipid digestion occur
small intestine
how are the nutrients carried away from the gut
absorbed into bloodstream through walls in small intestine
how are the villi adapted for efficient absorption of nutrients
many microvilli=
large surface area
rich blood supply
thin walls
2 functions of bile
emulsifies fat + neutralises food from stomach (HCI)
how are red blood cells adapted to carry oxygen efficiently
biconcave disc shape
contain pigment haemoglobin
no nucleus
name the blood vessel type that carries blood away from the heart to other parts of the body
artery
name the blood vessel type that carries blood from the organs back into the heart
vein
name the blood vessel type that is found within organs that link arteries and veins
capillaries
structural differences between arteries and veins
A: thicker walls, more elastic tissue, no valves
V: thinner walls, less elastic tissues, have valves
why can substances diffuse easily between capillaries and the cells?
thin capillary walls
what is the double circulatory system
one part carries blood between heart and lungs
the other carries blood between heart and other organs
name the vessels that supply oxygen to the heart
coronary arteries
name the large vessel that brings deoxygenated blood back inti the heart
vena cava
name the upper chambers of the heart
atria
name the lower chambers of the heart
ventricles
name the vessel that brings deoxygenated blood from the heart to the lungs
pulmonary artery
name the vessel that brings oxygenated blood from the lungs to the heart
pulmonary vein
which side of the heart has deoxygenated blood
right
name the large blood vessel that brings oxygenated blood out of the heart to the body
aorta
the function of heart valves
prevent back flow of blood
a method to unblock a coronary artery in the heart
stent
a drug that reduces blood cholesterol levels
statins
what can be used to replace a damaged heart valve
biological or mechanical valves
the function of the ribcage
protect the heart and lungs
what are communicable diseases
diseases caused by pathogens that can be transmitted from one individual to another
define pathogens
microorganisms that cause disease
define health
state of physical and mental wellbeing
four types of pathogens
bacteria
viruses
protists
fungi
how do bacteria make you ill
damage cells
produce toxins
how do viruses make you ill
reproduce inside body cells, causing damage
how can pathogens be spread
by air
droplet infection
direct contact
water
define binary fission
bacteria reproduction
what are antibiotics
chemicals used to kill bacteria inside human body
one method to prevent the spread of disease
isolation
maintain good hygene
destroy vectors
vaccination
a viral disease that leads to blindness and brain damage
measles
how can measles spread
droplet infection
how can AIDS be spread
sexual contact
exchange of bodily fluids
how can AIDS be treated
antiretroviral drugs to control it (not cure)
a viral disease in plants
tobacco mosaic virus
how does tobacco mosaic virus affect the plants
destroys chloroplasts = reduced photosynthesis
=stunted growth
which pathogen causes gonorrhoea
bacteria
how does gonorrhoea spread
sexual contact
symptom of gonorrhoea
yellow/green discharge from penis or vagina
pain on urination
how does your skin act as a defence against pathogen entry
barrier
antimicrobial secretions
microorganism layer
how does the trachea defend the body against pathogens
secrete mucus to trap pathogens
cilia move mucus to back of throat for swallowing
how does the stomach defend the body against pathogens
hydrochloric acid destroys microorganisms in mucus/food
3 way’s white blood cells defend the body
engulf pathogens
produce antibodies
produce antitoxins
what are antibodies
proteins that bind to specific antigens on pathogens
what are antigens
proteins on cell surface for recognition
define resolution
The ability to distinguish between two separate points
Which type of microscope has higher magnification and resolving power - Light or electron?
electron microscope
Why do we stain tissue samples before looking at them under the microscope?
to visualise/see structures clearly
how do you calculate magnification with a microscope
magnification = image/actual
what is the role of a nerve cell
carry electrical impulses
how have nerve cells adapted to their role
myelin sheath- insulation
very long
dendrites
synapses- neurotransmitters
what is the role of a muscle cell
movement
how have muscle cells adapted to their role
contract
mitochondria- energy
what is the role of a sperm cell
carry 1/2 DNA to fertilise the egg
how has the sperm cell adapted to its role
1/2 DNA
tail
mitochondria
what is the role of the root hair cell
absorbs water and minerals
how have root hair cells adapted to their role
large surface area
how have photosynthetic cells adapted to their role of photosynthesis
lots of chlorophyll
large surface area
large vacuole
what is the solute
the substance being dissolved
what is the solvent
the substance being dissolved into
what is the solution
the result of the solute and solvent
what is the type of cell division that produces egg and sperm cells
miosis
what evidence is used you study species that have become extinct
fossils
which hormones are given to women having IVF treatment
FSH and LH
name the target organ of the hormones used for IVF
ovaries
what are non-communicable diseases
non infectious diseases
cannot be transmitted
what does carcinogens mean
cancer causing diseases
for example: tobacco
what are benign tumours
growth of abnormal cells contained in one area
don’t invade other tissues
can become malignant if parts break off
what are malignant tumours
tumours that can spread to other parts of the body
what is a risk factor of developing cancer
smoking
obesity
common viruses
UV exposure
genetic factors
what are 2 ways to treat cancer
chemotherapy
radiotherapy
what is the carcinogen in tobacco smoke
tar
what does correlation mean
could be a link between variables
what does causal mean
definite link between variables
is photosynthesis endothermic or exothermic
endothermic
what is the equation for photosynthesis
carbon dioxide + water -> glucose + oxygen
what is cancer
an abnormal growth of cells
forms a mass of cells=tumor
causes of cancer:
lifestyle and choice:
alcohol
smoking
food intake
UV
genetics:
more inclined
what is the addictive substance in smoking
nicotine
what is the carcinogenic in smoking
tar
why shouldn’t you smoke when pregnant
contains carbon monoxide
making the baby oxygen deprived
leading to problems like premature, still borns, miscarriage and underweight babies
what does accuracy mean
close to the true value of
what does precise mean
values that are close together
what does a fair test mean
variables controlled
what is the required practical for testing for starch
get a leaf from a plant in sunlight and one from a plant in the dark
boil both leaves to kill them (stop photosynthesis)
put leaf into a test tube with ethanol
(ethanol boils at a low temperature) put test tube in boiling water for 10 mins
the ethanol removes chlorophyll (so you can see results)
test with iodine solution which tests for starch
if it contains starch- yellow brown to black ( one in sunlight
if it doesnt contain starch it will remain yellow
is aerobic respiration endothermic or exothermic
exothermic- released energy
what is the word equation for aerobic respiration
oxygen + glucose -> carbon dioxide + water
