Topic 4 Flashcards
(36 cards)
change in evolution
- there is variation in the population of giraffes de to mutations
- some giraffes have longer necks than others
- there is a struggle for existence as organisms compete to survive
- giraffes with longer necks will survie and reproduce
- allele for longer necks will be passed down
- over time giraffes with longer necks will survie and those that don’t will die
- this change of time i called evolution and ahppens trhough a process of natural selection
darwin and wallice
- came up with the thoery of natural selection independantly
- darwin was better recognises as he wrote a book on it
- wallice looked at camoflage
- studied different areas
why was dawrin’s idea controversial
against the idea that all species on earth were created by god
___________has__________
pentadactyl limb has 5 digits
why is the anatomy of the pentadactyl limb evidence for a common ancestor
its unlikely that the complex structure would have arisen multiple by chance
ardi
- 4.3 M
- big toe suggest climbing
- arms longer than legs
- brain the size of a chimpanzee
lucy
- 3.2M
- arched feet, no ape like toe,
arm/ leg length similar to humans - small brain but larger than ardi’s
turkana boy
- 1.6 M
- walked upwright, no ape liek big toe
- arms length more like humans
- similar to human size
restriction enzymes
cut the insulin gene with restriction enzymes leaving the insulin with sticky ends
cut plasmid with same restriction enzymes they will both have the same sticky ends
insert gene into plasmid, placed back into bacterium
how can we date stone tools
- simpler ones were older
- carbon 14
- deeper the stone or fossil the oler it is
why are fossils often found incomplete
- soft tissue decays quickly and not fossilised
- anaimls eat or move them
- crushed/ damaged/ chaged underpressure
- not found yet
joined bonds
DNA ligase joins the gene into the plasmid by forming forming bonds between nucleotides
insert genes into rice to make
golden rice, vitamin A and better eye sight, immune system
Gm crops can be…
drought resistant, herbicide resistant, pest resistant
tissue culture advantages
- effecient/ fast process
- can increase population of endangered species
- can grow plants all year round
- require little space
- can produce clones with desired colclusions
Explain why switching on the fan caused a change in the volume of water taken up by the
plant
fan causes air to move so water vapour leaves the leaf, increases rate of difusion/ transpiration causing plant to take up more water
Give one reason why the volume of water taken up by the plant was also measured
when the fan was not switched on.
to compare the effect as a contol
Explain the difference in the mean width of leaves in the shade and those in the sunlight
dark = wider leaves to absorb more light
Xerophytes are plants adapted to live in very dry conditions.
State two differences between the leaf structure of a xerophyte and the leaf structure shown
in Figure 1.
less stomata, sunken in pits
thicker waxy cuticle
leaf rolled
control variables in checking rate of photosytnetsis
light- use the same light source, dark room
co2-
temp- use thermometer
bubbles- replace with measuring cylinder
pondweed - use same amount each time
Use information in Figure 14 to explain why oxygen moved out of the leaf between 9 am and
midday.
more photosynthesis occurs in the day light so more oxygen diffuses
tissue
group of similar cells to carry out a specific function
tissue culture
growing cells on in a liquid containing nutrients/ solid medium (agar jelly)
this is sometimes called micropropagtion
steps of tissue culture
- cells taken from plant
- placed on growth medium that contains nutrients and hormones like auxins
- cells develop into tiny platelets
- plantlets grow in compost
all genetically identical
