cell specialisation Flashcards
what is it called when cells are specialised
differentiation
how are sperm cells adapted when it comes to genetics
they have half the genetic info of an adult cell
sperm cells: swimming to the ovum
they have a long streamlined tail to help them swim to the ovum
sperm cells: extra energy for swimming
extra energy for swimming is provided by many mitochondria
sperm cells: breaking into the ovum
their head contains enzymes which allow them to break into the ovum
what do nerve cells do
carry electrical impulses around the body
what does the axon do: nerve cell
it carries the electrical impulses from one part of the body to another
what is the axon covered in and why
myelin, to insulate the axon and speed the transmission of nerve impulses
what does the end of the axon have and what does this do
synapses which allow the impulse to pass from one cell to another
what do dendrites do in a nerve cell
increases surface area so other nerve cells can connect more easily
how are muscle cells adapted to contract
they contain protein fibres which can change their length
when a muscle cell contracts, protein fibres shorten decreasing the cell’s length
what are muscle cells packed full of
mitochondria
what are root hair cells covered in and why
in hair protrusions which increases the surface area of the root so it absorbs water and minerals mre effectively
what do root hair cells not have and why
chloroplasts as they’re underground
what do xylem do and what is it
a long tube which carry water and dissolved minerals from the roots to the leaves
xylem have t– w– that have l–
xylem have thick walls that have lignin providing support to the plant
what does lignin cause the xylem cells to do
the xylem cells are dead because of lignin
what happend to the end walls between the cells in xylem and what does this do
the end walls between the cells have broken down so the cells now form a long tube and dissolved minerals flow easily
what do xylem cells not have and why
no nucleus, no cytoplasm, no vacuole, or chloroplasts so its easier for water and minerals to flow
what do phloem tubes do
they carry dissolved sugars up and down the plant
what does the phloem vessel not have
no nucleus and a limited cytoplasm
what happend to the end walls of the vessel cells in phloem
the end walls have pores called sieve plates, these allow sugar to move through the interior
what does each phloem vessel have and how is this connected
phloem companion cell connected by sieve plates
what do phloem companion cells do
mitochondria in the companion cell provides energy to the vessel cell
