_A2_ 1 - nerves

Question 1

producer

Answer 1

an autotrophic organism (green plant) that convert light energy to chemical energy

Question 2

tropic level

Answer 2

the level at which an organism feeds in a food chain

they use 1st,2nd,3rd stage consumer to represent primary,secondary and tertiary consumers.

Question 3

Ecosystem

Answer 3

all the living and non living components in a specific habitat and their interactions/their different roles

Question 4

population

Answer 4

all of the organisms of one species, who live in the same place at the same time, and who can breed together.

Question 5

community

Answer 5

all the populations of different species that live in the same place at the same time, and who can interact with each other.

Question 6

consumer

Answer 6

a heterotropic organism that obtains their energy from organic compounds such as carbohydrates, lipids/fats,proteins

Question 7

niche

Answer 7

the role that species (an organism) plays in an ecosystem
eg.all primary consumer occupy the same niche
All decoposes perform thesame functione.g.same niche.
e.g. Humans can occupy many niche.

Question 8

How an action potential is generated at the receptor

Answer 8

= the stimulus will cause Na+ to diffuse into the membrane of the receptor cell.
= If enough Na+ ions enter, a threshold value will be reached and an action potential will be generated.

Question 9

All or Nothing

Answer 9

If the stimulation is strong enough and the threshold value is reached a full action potential will be generated, however,
If the stimulus is not strong enough, the threshold value will not be reached and no action potential is generated.

Question 10

Difference in structure of cell body

Answer 10

sensory=the cell body is found between an axon and dendron eg. outside the CNS.
Motor= Cell body is found inside the CNS at one end of the neurons.

Question 11

Difference in structure of Dendrites

Answer 11

sensory= Dendrites are at the end of the axon.
motor= Dendrites come off from the cell body

Question 12

Difference in structure

Answer 12

sensory= has an axon and dendron
motor= Only has an axon.

Question 13

Difference in structure of Dendron

Answer 13

sensory= Dendron is longer than its axon
motor= Has the longer Axon.

Question 14

saltatory conduction

Answer 14

=At the Myelin sheath sodium ions Na+ cannot pass through because it is impermeable to sodium.
=The only place Na+ can pass through at the nodes of Ranvier.
=when sodium diffuses down its electro chemical gradient it reaches a high concentration in the axon. So it diffuses in both directions along the axon
= This will open the Na+ voltage gated channel further along the axon creating an influx of Na+ ions at the next node
= this sets up alocalcircuit andresults in saltatory conduction.

Question 15

Suggest why myelinated faster for conduction

Answer 15

the Na+ channels are more concentrated at the nodes than where the myelinated regions are compared to non myelinated which may have the Na+ channels evenly spread out.

Question 16

Suggest why myelinated faster for conduction

Answer 16

the Na+ channels are more concentrated at the nodes than where the myelinated regions are compared to non myelinated which may have the Na+ channels evenly spread out.

Question 17

For myelinated/non myelinated howcan you increase conduction speed.

Answer 17

=faster conduction if you increase ;
-diameter of axon
-temperature
=more kinetic energy for diffussion to occur faster
=if gives too high-it denatures protein channels/pump Na+/ K+ channels, pumps.
=lso makes the cell membrane more permeable to Na+/K+
becuse its more fluid.

Question 18

Positive feedback

Answer 18

Na+ions enters axon through facillitated diffusion then makes more Na+ ions to diffuse in through Na+ voltage gated channels..