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Need help for the B1 exam tommorow?

AQA B1!!!!! Hi guys, if you are stuck on any questions for B1 or don't understand something please feel free to ask me. It will help for your understanding and my revision.
(edited 7 years ago)

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Reply 1
Avatar for mariyahx
mariyahx
6
bacteria 6 mark question
neurones at least 4 marker
Reply 3
Avatar for Nihaj
Nihaj
OP
2
Original post by CosineOfPi
neurones at least 4 marker


A stimulus is detected by the receptor cells. The receptor sends an electrical impulse to the sensory neurone. This electrical impulse travels through the sensory neurone till it reaches the synapse. The electrical impulse can't travel across the synapse (A synapse is the junction between two neurones) so instead a chemical is released which travels across from the sensory neurone to the relay neurone (across the synapse). An electrical impulse is then passed from the relay to the motor neurone. The motor neurone sends this electrical signal to the effector (muscle) which causes the reflex.
Original post by Nihaj
A stimulus is detected by the receptor cells. The receptor sends an electrical impulse to the sensory neurone. This electrical impulse travels through the sensory neurone till it reaches the synapse. The electrical impulse can't travel across the synapse (A synapse is the junction between two neurones) so instead a chemical is released which travels across from the sensory neurone to the relay neurone (across the synapse). An electrical impulse is then passed from the relay to the motor neurone. The motor neurone sends this electrical signal to the effector (muscle) which causes the reflex.


get in the "diffuse" classic AQA wanna hear it make a mnemonic for it SRSRME idk something like Simon Rides Silly Red Massive Elephants
Reply 5
Avatar for Nihaj
Nihaj
OP
2
Original post by mariyahx
bacteria 6 mark question


If you're talking about resistant bacteria:

When an antibiotic is overused bacteria can mutate and produce new anti biotic resistant strains. So when the antibiotic is used all the non-resistant pathogens are killed but the resistant bacteria survive. The resistant bacteria reproduce and the population increases. Only new antibiotics will be able to kill the resistant bacteria. This could lead to an epidemic if new antibiotics aren't found quick enough.
Reply 6
Avatar for Nihaj
Nihaj
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2
Original post by CosineOfPi
get in the "diffuse" classic AQA wanna hear it make a mnemonic for it SRSRME idk something like Simon Rides Silly Red Massive Elephants


Yes chemicals diffuse across the synapse.

But i believe for 4 marks you won't have to mention much about the synapse. Depends on the question really.
Reply 7
Avatar for hafsa23
hafsa23
2
Adult cell cloning please
Reply 8
Avatar for andew_451
andew_451
Original post by hafsa23
Adult cell cloning please


cloning isnt in edexcel biology one
Reply 9
Avatar for hafsa23
hafsa23
2
Original post by andew_451
cloning isnt in edexcel biology one


sorry i thought this thread was for AQA biology
Reply 10
Avatar for MathyJ
MathyJ
Original post by Nihaj
If you're talking about resistant bacteria:

When an antibiotic is overused bacteria can mutate and produce new anti biotic resistant strains. So when the antibiotic is used all the non-resistant pathogens are killed but the resistant bacteria survive. The resistant bacteria reproduce and the population increases. Only new antibiotics will be able to kill the resistant bacteria. This could lead to an epidemic if new antibiotics aren't found quick enough.

you could also include survival of the fittest and natural selection so the resistant bacteria survives.
guys please specify where it is AQA B1 or Edexcel B1, cheers!
Reply 12
Avatar for Nihaj
Nihaj
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2
Original post by hafsa23
Adult cell cloning please


Yes this is Aqa

So for this question lets take a cow for example

Firstly a body cell is taken from a cow. A egg cell is taken from a different cow. The nuclei from both cells are removed. The nucleus from the body cell is placed in the empty egg cell (because we removed the nucleus). Then the cell is shocked as it starts the cell division. The cell will divide and form an embryo which is then inserted into the womb of the surrogate mother.
Original post by hafsa23
Adult cell cloning please


I struggle badly on this type of question buy my teacher ssat down with me and now i get it!

1. Take a skin cell from the organism you want to clone...
2. Remove the Nucleus
3. Remove an unfertailised egg from an egg donor
4. Remove the eggs nucleus
5. Put the egg and the nucleus from the skin cell together and give an electric shock so they join
6. Give another electric shock to stimulate division into an embryo
7. Place the embryo into the surrogate mother's uterus
8. A clone of the organism you got the skin cell from will be born!

Hope this helps! x
Reply 14
Avatar for LaliG
LaliG
10
Do you know if we have to learn all the indicator species and what they do? E.g. fresh water shrimp, mayfly larvae..
Do we need to know what they are affected by and stuff ?

Thank you :smile:
Reply 15
Avatar for lou2471
lou2471
9
Adult cell cloning
1) an unfertilised egg cell is taken and the nucleus is removed
2) a complete set of chromosomes is inserted from an adult body cell (from the animal you want to clone)
3) the egg is stimulated by an electric shock causing it to divide like an embryo
4)when it is a ball of cells, it is implanted into an adult female (the surrogate mother) to grow
hope this helps :smile:
(edited 7 years ago)
Reply 16
Avatar for hafsa23
hafsa23
2
Original post by Nihaj
Yes this is Aqa

So for this question lets take a cow for example

Firstly a body cell is taken from a cow. A egg cell is taken from a different cow. The nuclei from both cells are removed. The nucleus from the body cell is placed in the empty egg cell (because we removed the nucleus). Then the cell is shocked as it starts the cell division. The cell will divide and form an embryo which is then inserted into the womb of the surrogate mother.


Thank you!x
Reply 17
Avatar for Nihaj
Nihaj
OP
2
Original post by LaliG
Do you know if we have to learn all the indicator species and what they do? E.g. fresh water shrimp, mayfly larvae..
Do we need to know what they are affected by and stuff ?

Thank you :smile:


Yes it has come up before.

These are free good indicators:
-Lichen
-Bloodworms
-Mayfly Larvae

Depending on the type of Lichen species we are able to see how much pollution is in the air. (Lichen are used to indicate the amount of sulphur dioxide in the air)

Bloodworms indicate high levels of water pollution.

Mayfly Larvae indicates low levels of water pollution.

Bloodworms and Mayfly Larvae are also indicators of the concentration of dissolved oxygen in water.

Oxygen levels are high in unpolluted water.

Oxygen levels are low in polluted water.
Reply 18
Avatar for hafsa23
hafsa23
2
Original post by lou2471
1) an unfertilised egg cell is taken and the nucleus is removed
2) a complete set of chromosomes is inserted from an adult body cell (from the animal you want to clone)
3) the egg is stimulated by an electric shock causing it to divide like an embryo
4)when it is a ball of cells, it is implanted into an adult female (the surrogate mother) to grow
hope this helps :smile:

yes this was helpful thanks ! x
Original post by Nihaj
A stimulus is detected by the receptor cells. The receptor sends an electrical impulse to the sensory neurone. This electrical impulse travels through the sensory neurone till it reaches the synapse. The electrical impulse can't travel across the synapse (A synapse is the junction between two neurones) so instead a chemical is released which travels across from the sensory neurone to the relay neurone (across the synapse). An electrical impulse is then passed from the relay to the motor neurone. The motor neurone sends this electrical signal to the effector (muscle) which causes the reflex.


Good detail....but you missed out CNS, or spinal cord/brain! Which is a crucial part of the reflex arc.
Also, (being picky, I know) you could add that the response is the muscle contraction.

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