2012 january Flashcards
what is sexual reproduction? (1)
fusion / joining / combining of gametes / egg and sperm / sex cells
the zorse was produced by sexual reproduction. why does the zorse have characteristics of a zebra and a horse? (2)
✏️ (mixture of) genes / DNA / genetic information / chromosomes
✏️ from both parents / horse and zebra
zorses are not able to breed. scientists could produce more zorses from this zorse by adult cell cloning. use information from the diagram and your own knowledge to describe how adult cell cloning could be used to clone a zorse (6)
✏️ skin cell from zorse ✏️ (unfertilised) egg cell from horse ✏️ remove nucleus from egg cell ✏️ take nucleus from skin cell ✏️ put into (empty) egg cell ✏️ (then give) electric shock ✏️ (causes) egg cell divides / embryo formed ✏️ (then) place (embryo) in womb / uterus
other than measles, which two diseases does the MMR vaccine protect against? (2)
✏️ mump(s) ✏️ rubella / german measles
to immunise someone against measles, a small quantity of the inactive measles pathogen is injected into the body. describe what happens in the body after immunisation to stop a person catching measles in the future (3)
✏️ white blood cells
✏️ (wbc) produce antibodies
✏️ in future / if re-infected antibody production rapid / fast(er) / quick(er)
the carbon in dead bean plants is returned to the atmosphere via the carbon cycle. describe this part of the carbon cycle (4)
✏️ microorganisms / microbes / bacteria / fungi / decomposers / detritivores / named
✏️ decay / breakdown / digest / decompose / rot (bean plant)
✏️ respiration (of microorganisms etc / aphids)
✏️ carbon dioxide released (from respiration of microorganisms etc / aphids)
students investigated a food chain in a garden. the students found 650 aphids feeding on one bean plant.
five ladybirds were feeding on the aphids. give two reasons why the biomass in the five ladybirds is less than the biomass in the bean plant (2)
✏️ not all digested / faeces
✏️ loss in urine
✏️ loss of CO2
✏️ not all eaten
what is a hormone? (1)
✏️ chemical messenger / message
✏️ chemical / substance produced by a gland
✏️ chemical / substance transported to / acting on a
target organ
✏️ chemical / substance that controls body functions
name an organ that produces a hormone (1)
gland / named endocrine gland eg pancreas, pituitary gland, testes, ovaries
how are hormones transported to their target organs? (1)
in blood/plasma or circulatory system or bloodstream
describe how the hormones FSH, oestrogen and LH are involved in the control of the menstrual cycle (3)
✏️ FSH stimulates oestrogen (production) / egg maturation / egg ripening
✏️ oestrogen inhibits FSH
✏️ LH stimulates egg / ovum release / ovulation
what scientific term describes a change in a gene? (1)
mutation
In 2006 blue-moon butterflies almost became extinct.
wolbachia bacteria killed males before they could hatch from eggs. oonly females were resistant to the bacteria.
In 2006 the number of male blue-moon butterflies had decreased to only 1 per cent of the population. two years later, the number of males was equal to the number of females. the numbers of male blue-moon butterflies in the population increased quickly after the new form of the gene had appeared. suggest why (3)
✏️ idea of mutant gene / new form / this allows hatching (of males)
✏️ (individual with advantage) (more) survive / (more) live / (more) don’t die
✏️ (so survivors) breed / reproduce
✏️ mutation / gene passed (from survivors) to offspring / next generation
before the clinical trials, drugs are tested in the laboratory. the laboratory trials are not trials on people. what is the drug tested on in these laboratory trials? (1)
✏️ cells
✏️ tissues
✏️ (live) animals / named
drugs must be trialled before the drugs can be used on patients. give three reasons why (3)
(to test for)
✏️ toxicity / check not poisonous / not harmful
✏️ interaction with other drugs
✏️ efficacy or to see if they work or check if they treat the
disease
✏️ dosage or how much is needed
