Specialized Cells And Stem Cells Flashcards
(18 cards)
What does a nerve cell do?
Carrys electrical signals
Describe a nerve cell
Long branched connections and insulating sheath
What does a sperm cell do?
Fertilise an egg
Describe a sperm cell
Streamlined with a long tail, large number of mitochondria to release energy
What does a muscle cell do?
Contracts to allow movement
Describe a muscle cell
Long, contains a large number of mitochondria
What does a root hair cell do?
Absorbs water and minerals from the soil
Describe a root hair cell
Hair like projections to increase the surface area
What does a xylem cell do?
Transports water and minerals from the roots to the stem and leaves. This process is called transpiration.
Describe a xylem cell
Made of dead cells with cell walls toughened by lignin. The water and minerals can only flow in one direction
What does a phloem cell do?
Carry dissolved sugars from the leaves to the rest of the plant to use or store- this process is called translocation.
What does a human embryonic stem cell do?
Can be cloned and made to differentiate into most cell types
What does a adult bone marrow stem cell do?
Can form many types of human cells e.g. blood cells
What are the uses for human embryonic stem cells and adult bone marrow stem cells?
Treatment with stem cells (including therapeutic cloning) may be able to help conditions such as diabetes and paralysis.
What does a meristems stem cell do?
Can differentiate into any plant cell type throughout the life of the plant.
What are the uses for meristems stem cells?
Used to produce clones quickly and economically for:
-Rare species that can be cloned to be protected from extinction
-crops or plant with pests or desies resistance can be cloned in large quantities for farmers to use
State some Stem cell advantages
-In therapeutic cloning an embryo is made eith the same genes as the patient so the body does not reject the tissue
-With adult bone marrow tissue can be matched to avoid rejection
State some disadvantages of stem cells
-There is a risk of infection with therapeutic cloning
-With adult bone marrow only a few types of cells can be formed
-Some people object on religious grounds
-Some people object on ethical grounds
