paper 2 Flashcards
define fertilisation
the fusion of a male and females gametes nucleus’
name 3 abiotic factors
humidty
temperature
light intensity
name 3 biotic factors
competition
diesease
predators
where in the body is glycogen stored?
liver
what is the function of insulin?
and how?
reduce blood glucose concentration
by increasing the absorption of glucose to the liver and muscles
how can you reduce the risk of developing diabetes?
regular excersise
eat a lower amount of carbohydrates
name 3 substances that can cause water pollution
toxic chemicals
sewage
fertiliser
define a reccessive disease
and gene
a disease which is only inherited if there are two copies of the allele
same but with a gene
what is an amino acid?
what is their function?
a molecule with at least 2 functional groups
they are the building blocks for protien and help bodily functions
where in the body are amino acids broken down?
liver
give 2 uses of water in plants
photosynthesis
support
give 2 advantages of farming animals indoors
less energy lost through movement
less energy lost through heat
give 2 disadvantges of farming animals indoors
disease spread faster
aggressive behaviour
define mutation
a change in a gene or chromosome
how does the dilation of blood vessels cool the body?
as there is more blood flow to the surface of the skin
name the route of the heart
vena cava
right atrium
right ventricle
pulmonary artery
pulmonary vein
left atrium
left ventricle
aorta
define osmosis
the movement of molecules through a semi-permeable membrane down a concentration gradient
define active transport
the movement of molecules up a concentration gradient,
define homeostasis
the regulation of conditions in the body to maintain a stable environment
explain what these do :
receptors
control centres
effectors
detect the change
interpret and decide what needs to be done
carry out the change
How does the nervous system deliver signals?
describe these
through electrical impulses via nerves
very fast and precise
how does the endocrine system carry out changes?
via hormones in the blood stream
how is the endocrine system different to the nervous system?
it is slower
it lasts longer
it is more generalised
it travels through the blood
name 2 types of effectors
glands
muscles
what are 2 adaptations of neurones
extended shape (helps travel across body)
fine branches (allows them to pass signals to other nerve cells)
what is a synapse
the gap between 2 nerve cells
how do signals pass across a synapse?
chemicals from one nerve cell diffuse across the synapse, triggering an electrical impulse in the next cell
name the 3 types of neurones and what they do
sensory- send signal from receptor to the cns
motor- sends signal of what to do to the effectors
relay- passes signal from sensory to motor neurones
what is a reflex?
an automatic response to a stimulus
in the brain
what does the cerebal cortex control?
consciousness
intelligence
memory
etc
in the brain
what does the cerebellum control?
balance
co-ordination
in the brain
what does the hypothalamus control?
regulating body temp
sending signal to the pituitary gland
in the brain
what does the medulla control?
unconscious activities
what does the cornea do?
how does it get oxygen
refracts all the light that passes through it
through diffusion as it has no blood vessels
what does the iris do?
control the size of the pupil
what does the lens do?
refracts light but can change how strongly to focus the light onto the retina
what are the 2 different receptor cells in the retina?
cone- colour of light
rod- more light sensitive (black and white)
what does the optic nerve do?
transfers impulses from receptor cells to the brain
what is hyperopia and myopia?
hyperopia= long sightedness
myopia= short sightedness
define thermoregulation
the control of our internal body temperature
why is 37 the body temperature?
as it is the optimal temperature for enzymes
thermoregulatory system
how does the body warm up?
contract erector muscles
vasoconstrict blood vessels near surface of skin
shiver
thermoregulatory
how does the body cool down?
sweat
vasodilate blood vessels near surface of skin
relax erector muscles
what is the function of the pituitary gland?
acts as a master gland- tells other glands to secrete hormones and secretes a variety of hormones itself
what is the function of the thyroid gland?
produces thyroxine, this regulates the rate of metabolism and helps growth and development
what does the pancreas gland do?
secrete insulin - controls blood glucose concentration
what is the name of the undifferentiated cells neurones develop from?
stem cells
define a genome
the entire set of genetic material in an organism
this refers to alleles
define homzoygous and heterozygous
homozygous- 2 copies of the same alleles
heterozygous- 2 different alleles
define genotype and phenotype
genotype- complete collection of alleles
phenotype- characteristics obtained from the genotype
what is an allele?
different versions of the same gene
what is a nucelotide
a monomer that makes up dna
what 3 things make up a nucleotide
phosphate
sugar
base
dna
what bases always pair together?
A+T
G+C
what does glucagon do and how?
increases blood glucose levels by causing cells (e.g liver) to release its glycogen
what demographic does type 1 diabetes occur in?
children and teenagers
what demographic does type 2 diabetes occur in?
older, more unhealthy people
give 3 ways type 1 diabetes is monitored
- inject insulin
- regular excersise
- monitor diet
what is the underlying issue in type 2 diabetes?
the bodys tissue becomes resistant to insulin
what are the 3 main functions of the kidneys?
- filter blood
- remove urea + waste
- regulate levels of useful things e.g ions
which hormone is responsible for water levels?
ADH
what hormones stimulates the uterus to develop?
oestrogen
what organ are FSH and LH released from?
Pituitary gland
what organ stimulates an egg to be released?
LH
what does the hormone FSH do?
stimulate the ovaries to mature an egg
give 3 effects on the body adrenaline has
- increased heart rate
- increased blood pressure
- increase blood flow to muscles
what conversion of substances does adrenaline cause?
glycogen to glucose
what happens if thyroxine levels are too low?
the pituitary gland produces TSH to stimulate the thyroid gland to release thyroxine
plants
what are auxins?
hormones which control growth - found in the tips of roots and shoots
what does phototropic and geotropic mean?
phototropic- plants shoots grow towards light - roots away
geotropic- plants roots grow with gravity - shoots opposite way
where do auxins accumulate in shoots?
the shaded side
what 3 things does the hormone gibberellin in plants do?
- induce flowering
- increase fruit size
- control dormancy
what does the plant hormone ethene do?
stimulate ripening
how can auxin kill weeds?
stimulating too much growth will disrupt the growth pattern, killing it
give 2 things which increase the risk of mutation
carginogens (harmful chemicals)
radiation (e.ggamma rays)
what are the 3 types of mutations to a base sequence?
substitution- a base is changed to another base
insertion- an extra base is inserted into a sequence
deletion- a base is deleted from a sequence
what is a codon?
a set of 3 bases which codes for 1 amino acid
how can base mutations change an enzymes activity?
- amino acids will change which make up the enzyme
- active site may change
- no longer complimentary to substarte
- enzyme-substarte complexs wont form
what are the male and female plant gametes?
male- pollen
female- egg
what process creates gametes?
meiosis
what is a haploid cell and what is a diploid cell?
haploid- cell with 23 chromosomes
diploid- cell with 46 chromosomes
what process do bacteria cells use to reproduce?
binary fission
what type of disease is cystic fibrosis?
reccessive
what type of disease is Polydactyly?
dominant
give 1 sympton of cycstic fibrosis
sticky mucus in the airways of lungs
what 2 factors contribute to variation in individuals?
- environment
- inheritance
what is speciation?
an evolutionary process where a population evolves to become its own species
what is genetic engineering?
transferring a gene which creates a desirable characteristic from one organism to another
give 3 ways genetic engineering can improve crops
- increase crop yield
- increase crop quality
- resistance to disease
what is gene therapy?
the treatment of an inherited disorder by giving a patient a healthy copy of their faulty gene
describe the steps of genetic engineering for human insulin
- isolate insulin gene from human dna
- insert gene into a vector such as plasmids
- insert vector into a host bacterium
- allow bacterium to divide and produce insulin
what are behavourial adaptations?
adaptations to the way an organism behaves or acts
what are functional adaptations?
adaptations to the processes inside of an organism
