specialised cells

sperm cells function

to carry the male DNA to the egg cell (ovum) for reproduction

sperm cell characteristics

• long tail for swimming

• mitochondria in the middle piece to supply energy for cell’s movement

• acrosome (head) penetrates egg cell membrane

• haploid nucleus - 23 chromosomes

egg cell function

specialised to accept a single sperm cell to develop embryo

egg cell characteristics

• surrounded by special cell membrane that can only accept 1 sperm - becomes impermeable afterwards

• Alot of mitochondria to provide energy for embryo’s growth

• haploid - 23 chromosomes

ciliated cells function

specialised to waft bacteria/other particles trapped by mucus up to the throat (to be coughed out) or down to the stomach (to be digested)

ciliated cells characteristics

• long hairs (cilia) waft bacteria trapped by mucus to the stomach - where they are killed by stomach acid (this protects our body against illnesses)

root hair function/characteristics

takes up water by osmosis and mineral ions by active transport from the soil

characteristics

• large surface area so more water can move in

• large vacuole affect the speed of movement of water from the soil to the cell

• mitochondria provides energy from respiration for the active transport of mineral ions into root hair cell

red blood cell functions/characteristics

specialised to transport oxygen from the lungs to the rest of the body

characteristics

• contains a haemoglobin to carry oxygen molecules

• no nucleus for more space to carry oxygen

• flat disc shape with dips on both sides (biconcave) gives them a large surface area and better chance of absorbing as much oxygen as they can in the lungs

villi function/characteristics

structures about 1mm long in the small and large intestines. millions of them poke out to absorb digested food and water into the blood

characteristics

• large surface area

• thin walls that are 1 cell thick

• cells of the lining have tiny hairs to absorb more food/water

nerve cells functions/characteristics

transmit electrical signals in the nervous system

characteristics

• they’re thin and carry messages up and down the body over long distances very quickly

• nerve cells have branched connections at end to join to other nerve cells to pass messages around the body

• have a fatty layer (myelin sheath) surrounding them which increases the speed the message can travel