cell specialisation DEFINITELY IN EXAM

Question 1

define cell differentiation

Answer 1

they have adaptations which help the to carry out their specific function

Question 2

sperm cell:

1. what is a sperm cells function
2. how are sperm cells adapted for this function

Answer 2

1. to join with an egg cell (fertilisation)
2. • sperm cells only have half the genetic information of a normal adult cell
     - long tail which allows them to swim to the ovum(streamlined to make this easier)
     - full of mitochondria provide the energy needed for swimming
     - contain enzymes which allow them to digest their way through the outer layer of the ovum

Question 3

nerve cell:

1. what is a nerve cells function
2. how are nerve cells adapted for this function

Answer 3

1. to send electrical impulses around the body
2. • long axon to carry the electrical impulses from 1 part of the body to another
     - myelin insulates the axon and speeds up the transmission of nerve impulses
     - synapses on the end of axons allow the impulse to pass on from 1 nerve cell to another
     - dendrites increase the surface area so other nerve cells can connect more easily

Question 4

muscle cells:

1. what is a muscle cells function
2. how are muscle cells adapted for this function

Answer 4

1. to contract
2. • contain protein fibres which can change their length
     ( when a muscle cell contracts these protein fibres shorten decreasing the length of the cell)
     - lots of mitochondria to provide energy for muscle contraction
     - muscle cells work together to form muscle tissues

Question 5

root hair cells:

1. what is a root hair cells function
2. how are root hair cells adapted for this function

Answer 5

1. the hairs increase the surface area of the root so it can absorb more water and dissolved minerals more effectively
2. • root hair increases the surface area of the root
     - root hair cells don’t contain chloroplasts as they are underground

Question 6

xylem cells:

1. where are xylem cells found
2. what are xylem cells function
3. how and why are they suited for their function

Answer 6

1. in the plant’s stem
2. they carry water and dissolved minerals from the roots to the leaves
3. • thick walls containing lignin which provides support to the plant
     ( cell walls are sealed with lignin which the xylem cells to die)
     -end walls of the cell are broken, cells form a long tube so water and dissolved minerals can flow easily
     - no nucleus, cytoplasm, vacuole, chloroplasts (no internal structures) this makes it easier for water and minerals to flow

Question 7

phloem cells:

1. what is the function of phloem cells
2. how and why are phloem cells adapted for their function

Answer 7

1. carry dissolved sugars up and down the plant
2. phloem vessel cells have no nucleus and limited cytoplasm
   end walls if the vessel cells have pores called sieve plates (allow dissolved sugars to move through e inside of the cell)
   mitochondria in the companion cell provide energy to the phloem vessel cell