Revision Leaflet- Unit 2 Flashcards
The cells in organs are?
Specialised for their functions.
Stem cells in animals can?
Can divide and have the potential to become different types of cells.
Stem cells are involved in?
Growth and repair
Meristems are where?
Cell division takes place in plants and so are where growth occurs
The cells produced at meristems are?
Non-specialised and have the potential to become many types of plant cell e.g. Xylem, phloem, mesophyll
What is the CNS made up of?
Brain and spinal cord
What does the brain contain?
- cerebrum
- cerebellum
- medulla
What does the cerebrum do?
Stores memories, receives information from our sense organs and controls our actions by sending messages out to the muscles or to glands.
What does the cerebellum control?
Controls co-ordination and balance.
What does the medulla control?
Breathing and heartbeat.
What do the receptors in our sense organs detect?
Stimuli in our surroundings and produce electrical impulses
What do sensory neurons carry?
Electrical impulses to the CNS.
The three types of neurons?
-sensory
-relay
-motor
Make up a reflex arc and bring about fast responses
What is the gap called between each 2 neurons?
Synapse and the electrical impulses are carries across the gap by chemicals.
what do endocrine glands release?
Hormones into the blood stream.
Hormones work on their?
Specific target cells which have receptor proteins they can attach to.
What does the pancreas control?
Our blood glucose level by producing two hormones, insulin and glucagon.
The target cells for insulin and glucagon are in the?
Liver
When is insulin released?
When blood sugar level is high.
In the response to insulin, what does the liver do?
Converts glucose to glycogen for storage.
When is glucagon released?
When blood sugar levels are to low.
In the response to glucagon the liver concerts?
Glycogen back to glucose.
What is diabetes cause by?
Either the pancreas not releasing enough insulin or the liver not responding to it.
Body cells are?
Diploid
Gametes are?
Haploid
Make gametes are?
Sperm and pollen cells
Female gametes are?
Egg cells and ovules
Sperm cells are produced in the?
Testes
Egg cells are produced in?
Ovaries
Pollen is produced in a flowers?
Anther
Ovules are produced in a flowers?
Ovary
What does variation mean?
Differences between organisms, and these differences may be caused by their genes.
What is discrete variation?
The organisms can be places in distinct groups, e.g. Male or female, tongue roller on non-roller