Biology B2 Revision All Topics

Specialised Cells ­ Fat Cells
· They have a smaller
cytoplasm than
normal, more fat can
be stored.
· Few mitochondria,
they need little
energy.
· They can expand as
they fill up with fat…read more

Specialised Cells - Cone cell
· Light sensitive layer of the
retina, allow us to see in
colour.
· Outer segment has visual
pigment, changes
chemically in coloured
light (uses energy).
· Middle segment packed
with mitochondria for
energy.
· The nerve endings
(synapse) connects the
optic nerve to the brain.…read more

Specialised Cells ­ Root hair cell
· Roots have hairs to
increase surface area for
absorption of water.
· Large permanent
vacuole, to affect the
movement of water from
the soil across the root
hair cell.
· Root hair cells are always
positioned close to xylem
tubes, they carry water to
the rest of the plant.…read more

Specialised Cells ­ Sperm cell
· Long tail to swim towards
the egg.
· The middle section has
lots of mitochondria to
provide the energy to
swim.
· Acrosome has chemical
enzymes for breaking
through the egg.
· Large nucleus containing
the DNA to be passed on.…read more

Waste!
· Herbivores produce lots of undigested
waste material, so need a bigger intake
of food.
· Carnivores digest all their meat, so do
not need to eat as often and do not
produce as much waste.…read more

Movement!
· Muscles need energy to contract
· This energy comes from respiration
· Biomass taken in is used up as an
energy resource for movement…read more