possible questions for bio wa3
excretion
human reproductive system
infectious diseases
cardiac cycle
describe the primary and/or secondary immune response
how do vaccinations work
what are superbugs
define vaccinations
how to overcome superbugs
how does antibiotic resistance occur in bacteria
why do viruses requrie a host cell
why does an antibiotic not work on viruses
click to edit
how do antibiotics work
click to edit
what are antibiotics
click to edit
click to edit
click to edit
state the functions of aminotic sac and fluid before birth
structure of hiv virus
describe implantation
click to edit
describe fertilisation
click to edit
describe the menstrual cycle
click to edit
where do sperm come from
define sexual reproduction
define asexual reproduction
asexual reproduction is the process resulting in the productin of genetically identical offpsring from one parent
increase dosage of antibiotics/change antibiotics used
signs of kidney failure
click to edit
click to edit
where does selective reabsorption occur:
click to edit
why is there a high concentration of glucose in a diabetic's pee
click to edit
describe and explain high pressure in glomerululs
describe the journey of urine from the kidney to the urethra
presence of red blood cells/protein in blood
click to edit
click to edit
sexual reproduction is the process of the fusion of nulei from female and male gametes to form a zygote and the production of a genetically dissimilar offpsring
testes
blood enters the glomerulus more readily through the wider afferent ateriole than it can leave through the narrower efferent ateriole. as a result, blood dams up in the glomerulus, creating a high blood pressure. this high pressure provides the main force required for the filtration process. this pressure forces blood plasma out of the glomerular capillaries into the bowman's capsule along the entire length of the glomerulus
antibiotics are substances that kill or inhibit the growth or reproduction of a bacterium
inhibit the synthesis of cell membrane-->breaking up cell membrane
inhibit the synthesis of bacterial cell wall--> unable to resist expansion when water enters the cell
inhibit the protein synthesis in ribosomes-->preventing ribosomes from synthesising polypeptides
inhibit enzyme action--e.g. not able to produce folic acid
bacteria develop resistance to certain antibiotics after being exposed to it. bacteria that are less sensitive to the antibiotic can evade the action of antibiotics, especially when the given dose of antibiotics is not finished. the bacteria go on to reproduce, and more bacteria in the population are resistant to antibiotics
superbugs are bacteria that are resistant to many types of antibiotics
a vaccination is a technique used to induce the immune system to develop an acquired immunity against a specific disease using a vaccine
antigens in the vaccination trigger the production of antibodies from white blood cells
secondary response: when a person is exposed to the pathogen after a vaccination, there is a sharp increase in the level of antibodies produced
primary response:when the vaccine is given, white blood cells become activated and produce antibodies
viruses are unable to perform metabolic processes or
why are viruses classfied as non living?
day 6-13: fsh stimulates the development of follicles in the ovary. usually one of the follicles would develop into a graafian follicle. fsh stimulates the production of oestrogen which stimualtes the growth and repair of the uterine lining, allowing the uterine lining to be thick and spongy with blood vessels. high levels of oestrogen inhibit the production of fsh so that no more follicles can develop, and stimulates the pituitary gland to produce the lutenising hormone (lh)
day 14: lh stimualtes ovulation, the graafian follicle ruptures and releases the ovum. lh stimulates the formation of corpups luteum
day 15-28: corpus luteum secretes progesterone and some oestrogen. progesterone stimualtes the uterus to maintain and further thicken the uterine lining and be supplied with blood capillaries, preparing for implantation of embryo. progesterone inhibits ovulation and the production of lh and fsh. the corpus luteum breaks down at the end of this stage if the ovum is not fertilised. progestrtone levels drop and the uterine lining breaks down. [repeat]
day 1-5: low levels of progesterone and oestrogen causes the uterine lining to break down shed as menstrual blood through the vagina. pituitary gland secretes follicle stimulating hormone (fsh)
click to edit
cillia lining the oviduct sweep the fertilised egg or zygote along the oviduct. peristaltic movement of the oviduct also helps the zygote move towards the uterus. the zygote divides by mitosis to form a hollow ball of cells called embryo.the developing embryo moves down the uterus and eventually embeds itself in the uterine lining
supports and cushions the foetus before birth
as it cannot be compressed, it protects the fetus againt machinical injury
absorbs shock
allows the fetus a certain degree of movement
lubricates and reduces friction in the vagina during birth
a diabetic patient is unable to store excess glucose as glycogen in the body. hence, there is high concentration of glucose in the blood. the glucose is filtered off at the glomerulus. since the nephrons are unable to reabsorb all the glucose fast enough, a lot of glucose passes out in the urine
loop of henle: some water is reabsorbed
distal convoluted tubule: water and smaller concentration of sodium ions and chloride ions rerabsorbed
proximal convoluted tubule: all glucose, amino acids and vitamins are reabsorbed through the walls of the nephron into the surrounding capillaries. 85% of the sodium and chloride ions are reabsorbed. the active uptake of sodium and other ions into the blood increases the water potential in the nephron, and this causes the water to leave the nephron into capillaries by osmosis
collecting duct: some water (as required)
click to edit