Science. Flashcards
gsce revision
What is downsydrome
problems with chromosomes/genes they have 47 chromosomes in each nucleus
Down syndrome’s get a test called a?
karyotype
If 2 alleles are the same as eachother they are?
Homozygous
If 2 alleles are different they are?
Heterozygous
genetic screening is?
Testing people for allele/condition
why do ladies refuse the amniocentesis test?
It causes risk of miscarriage
Advantage of blood test.
Lower risk of miscarriage
Disadvantage of blood test
Less accurate result
Genetic engineering is?
Modification of an organisms genome
Where is insulin produced?
pancreas
What are receptors/efforters are linked by a?
co- ordinater
What are the 2 co-ordinaters?
brain or spinal cord
Nerve cells are also known as?
Neurones
Reflex actions
don’t involve any time to think bc they don’t involve brain
Reflex reactions…
By pass brain for extra speed.
3 things reflex actions have in common…
occur quickly. automatic. Don’t involve thinking.
Sensory neurone…
carries impulses from receptors to CNS
association neurone…
connects sensory with motor neurone.
motor neurone…
carries impulses from CNS the an effector.
what are the gaps called?
synapse
hormones are…
chemical.
hormones are produced by?
Glands
how do they travel around the body?
in the blood
Eg of a hormone?
insulin
advantage/ disadvantage of insulin
A) quicker. Less risk of allergy to insulin.
D) some people have ethical issues.
Recessive…
allele that shows if 2 are present
Type 1 diabetes is?
genetic inherited disease
Allele is?
form of gene which appears
dominant is?
overrides allele if genotype is heterozygous
diabetes is treated by?
insulin
what does amniotic fluid do?
cushions foetus
what causes cystic fibrosis?
mutation
shape of DNA
double helix
Diabetes is…
if insulin no longer works to lower blood glucose levels
symptoms of diabetes..
tired, thirst, glucose in urine
type 1 diabetes…
usually begins in children, pancreas stop producing insulin, insulin taking as medication throughout life.
type 2 diabetes…
Occurs in older people, Linked to lack of exercise, can be controlled by medication.
if diabetes isn’t treated properly you can be effected by:
eye damage, kidney damage, heart disease, strokes.
Plants r left on windowsills because
the plant will receive more light meaning more photosynthesis and plant will grow more.
auxin is…
growing hormone. produced in growing shoot tips of plant.
Male sex cell
sperm cell
Female sex cell
egg
function of testes?
produce sperm
scrotum?
Sac to protect testes
sperm ducts
carry sperm to urethra
prostate gland
allows travelling of sperm to feed egg
Ovaries.
Produce eggs
oviducts
transports eggs to ovaries
uterus
supports development of fertilised egg
Cervix
Controls opening of uterus
Fertilisation takes place in the…
Oviducts.
Amnion…
sac which contains amniotic fluid
baby is ready to be born after…
40 weeks
what is respiration
process that releases energy from food in cells
what is exothermic?
chemical reaction which releases energy (heat)
word equation for respiration..
glucose+ oxygen > carbon dioxide+ water+ energy
Symbol equation…
C6 H12 O6+ 6O2 > 6CO2+ 6H20+ energy
cancer is…
uncontrolled cell division caused by damage to genes
what is phototropism?
plant growth response, plant stems growing in direction of light
Progesterone
prepares uterus for pregnancy.
contraception is..
stops possibility of pregnancy when having sex.
3 types of contraception
chemical, surgical and mechanical(physical)
condom…
acts like a barrier stopping sperm from entering woman
Variation is…
differences between people or living things
continuous…
data can’t be set into groups clearly usually represented in histogram.
discontinuous…
data can be put in groups represented using a bar chart
Causes of variation…
our genes/environment
who was the famous naturalist?
Charles darwin
evolution can…
lead to formation of new species
what are fossils?
remains of living organisms
what’s extinct?
there’s no living examples left
reasons of extinction…
climate change.
hunting my humans/animals
Loss of habitat
what is endangered species?
animals at risk of becoming extinct
communicable disease…
can be passed from 1 organism to another.
what is communicable disease caused by?
bacteria, fungi, virus
what does the skin do against microorganisms?
acts as a barrier to stop them getting in
what does blood clotting do against microorganisms?
prevents them getting through cuts.
what are antibodies?
chemical produced by one type of white blood cell (lymphocytes)
what are the 2 types of immunity?
active and passive.
what are medicines?
drugs to help you feel better or reduce pain.
what are antibiotics?
chemicals produced by fungi to kill bacteria.
antibiotic resistance is a problem in hospitals because?
many people in hospitals are alreadly ill. Patients may have open wounds. Many antibiotics are used in hospitals
how can u stop antibiotic resistance from spreading?
isolate patients. Have strict hygiene rules. Avoids overuse of antibiotics
What is binge drinking?
drinking excessively over a short period of time
What’s the 1st antibiotic discovered
penicillin
what is photosynthesis?
process where plants make their own food by absorbing light energy and changing it to chemical energy
