the heart Flashcards
describe the role of arteries and their characteristics
carries blood away from the heart
thick walls and thin lumen to withstand high pressure
describe the role of capillaries and their characteristics
one cell thick to allow fast diffusion between blood and cells –>permeable walls
carry blood at low pressure
role is to exchange nutrients and waste products with tissues
describe the role of veins and their characteristics
carries blood back to the heart
thin walls wide lumen,valves to prevent the backflow of blood
what causes Coronary heart disease
when the artery supplying blood to the heart becomes blocked with fatty deposits
How can CVD be treated
stents-metal mesh that can be inserted to open up the vessel
statins-drugs that reduce the deposits of fatty material
what is transpiration
loss of water vapour from the leaves through the stomata
translocation?
phloem carrying sugars and other nutrients where they are needed
What are lymphocytes
type of WBC which produce antitoxins to neutralise toxins made by pathogens and antibodies that bind to the antigen of a pathogen but only if they fit. These stop viruses from infecting cells and cause them to clump together
what are phagocytes
WBC ingests pathogens clumps
what is glucose used for
respiration
making starch/fat to store energy
making cellulose
making amino acids for proteinsynthesis
what needs to be regulated in our bodies
blood glucose levels
internal temperature
water levels
what is a hormone
a system of glands that secretes hormones to send signals to effectors transported via blood(slower than nervous system)
name some methods of contraception
FSH inhibiting pills so no eggs mature
progesterone injection/implant to stop eggs from being released
condom/diaphragm: stops sperm from entering vagina
IUD: copper coil stops egg from embedding in lining
avoid sex
clamping oviduct/cut sperm
causes of infertility
lack of fsh/lh
fertility treatement
fsh/lh injections
IVF in vitro fertilisation->hard and expensive
eggs collected after inducing release with LH to be fertilised in a lab viable embryos inserted back into woman’s uterus
risks of ivf
low success rates
chances of multiple embryos to develop
what is a diploid cells
23 pairs of chromosomes
what is a haploid
23 chromosomes in total
describe the process of meiosis
chromosomes in a diploid cell are copied similar chromosomes are paired up and genes are swapped between them
cell divides to produce 2 diploid cells
these divide again to produce 4 haploid cells(gametes)
by which process does asexual reproduction take place
MITOSIS
By which process does sexual reproduction take place
MEIOSIS
Sexual repro advantage
offspring can become better adapted to the environment due to variation
asexual repro advantage
only one organism required
genome
the entire genetic code in an organism
DNA
double helix polymer that stores genetic code
gene
portion of DNA that codes for a protein
genotype
an organisms specific genetic code
phenotype
how this code is expressed in physical characteristics
what are alleles
different versions of the same gene
Homozygous
one type of allele
heterozygous
diffrent types of alleles eg Bb
what alleles is polydactyl caused by
caused by a dominant
what alleles is cystic fibrosis caused by
caused by a recessive allele
describe species
organisms that are considered to be of the same species if they can produce fertile offspring
what alleles determine sex
XX=female
XY=MAN
what is selective breeding
breeding organisms that have desired characteristics to produce offspring in which they are more pronounced
describe the process of genetic engineering
1.desired gene is cut from another organisms DNA using enzymes
2.this gene is then inserted into a vector eg bacteria plasmid or virus
3.vector inserts gene into cells of another organism early stages of its development
examples of genetic engineering
insulin producing bacteria
Genetically modified crops(eg. golden rice which produces Vitamin A)
disease resistant crops
what are fossils
decayed remains of organisms
types of fossils
imprints
mineralisation–>rocks
soft organic tissue if the conditions for decay were not present
how is the binominal name written
Genus+species
name the 3 domains
archaea(primitive bacteria)->extramorphilles
bacteria(true bacteria)
eukaryota(animals and plants)
what is inter dependence
organisms depending on each other for survival—>this leads to the formation of a community
abiotic factors
non living factors
eg. light ,temp, moisture, soil pH, CO2 and O2 concentration
biotic factors
the impact of other organisms on an ecosystem
eg. food, new predators , new pathogens
where is the peace maker located
in the right atrium
