A2 Biology | Post your doubts here

[ousamah112]

hey..is it true that the regulation/homoeostasis questions will only come in part b???

 

[user]

hey..is it true that the regulation/homoeostasis questions will only come in part b???

nopes i dont think so..i remember seeing questions in section a too..!

 

[omair tahir]

Same is wid me wish u and every1 else best of luck and wish me luck too Allah karam karey humsab pr Ameen

 

[angelgirl:)]

we all need them..!! each of us gotta pray 4 everyone

sure...

 

[omair tahir]

Nop it can be in section A too
Biology is i think the only subject in whch u can see applications in section too
Examiner of biology likes to give shocks

 

[ousamah112]

nopes i dont think so..i remember seeing questions in section a too..!

yeah they were, few years back.. but my teacher said that the whole questions regarding that chap now only come in section b...

 

[user]

Explain why variation is important in selection;

​

1. ref. continuous / discontinuous variation ;​

2. genetic / inherited variation ;​

3. variation in phenotype / characteristics / AW ;​

4. (can be due to) interaction of genotype and environment ;​

5. e.g. of characteristic that influences survival ;​

6. ref. intraspecific competition / struggle for existence ;​

7. those with favourable characteristics survive / AW ;​

8. pass on favourable characteristics to offspring ;​

9. those with disadvantageous characteristics die ;​

Variation means the presence of different characteristics or traits. There will be genetic variation within the population. The interaction of the genotype and environment results in phenotypic variation. Variation results in different survival rates of organism, which ultimately leads to reproductive success or failure. Organisms with most suitable traits and those that are best adapted to a stable environment have a survival advantage. Those surviving better get more chances of reproduction. They pass on their favourable characteristics to their offsprings and their number further increases. Whereas, those with disadvantageous characteristics, cannot survive, and die.
^need this answer to be improved a bit... hassam angelgirl:)

 

[angelgirl:)]

Nop it can be in section A too
Biology is i think the only subject in whch u can see applications in section too
Examiner of biology likes to give shocks

lol..

 

[angelgirl:)]

Explain why variation is important in selection;

​

1. ref. continuous / discontinuous variation ;​

2. genetic / inherited variation ;​

3. variation in phenotype / characteristics / AW ;​

4. (can be due to) interaction of genotype and environment ;​

5. e.g. of characteristic that influences survival ;​

6. ref. intraspecific competition / struggle for existence ;​

7. those with favourable characteristics survive / AW ;​

8. pass on favourable characteristics to offspring ;​

9. those with disadvantageous characteristics die ;​

Variation means the presence of different characteristics or traits. There will be genetic variation within the population. The interaction of the genotype and environment results in phenotypic variation. Variation results in different survival rates of organism, which ultimately leads to reproductive success or failure. Organisms with most suitable traits and those that are best adapted to a stable environment have a survival advantage. Those surviving better get more chances of reproduction. They pass on their favourable characteristics to their offsprings and their number further increases. Whereas, those with disadvantageous characteristics, cannot survive, and die.
^need this answer to be improved a bit... hassam angelgirl:)

hmmm i guess if u write this u will gain full credit...

 

[user]

hmmm i guess if u write this u will gain full credit...

what about the first ms point? any idea..and jazakAllah khairenn

 

[ousamah112]

what about the first ms point? any idea..and jazakAllah khairenn

Continuous variation
In continuous variation there is a complete range of measurements from one
extreme to the other. Height is an example of continuous variation -
Discontinuous variation
This is where individuals fall into a number of distinct classes or
categories, and is based on features that cannot be measured
across a complete range. You either have the characteristic or
you don't. Blood groups are a good example: you are either one
blood group or another - you can't be in between. Such data is
called discrete (or categorical) data. Chi-squared statistical
calculations work well in this case.

 

[user]

Continuous variation
In continuous variation there is a complete range of measurements from one
extreme to the other. Height is an example of continuous variation -
Discontinuous variation
This is where individuals fall into a number of distinct classes or
categories, and is based on features that cannot be measured
across a complete range. You either have the characteristic or
you don't. Blood groups are a good example: you are either one
blood group or another - you can't be in between. Such data is
called discrete (or categorical) data. Chi-squared statistical
calculations work well in this case.

how do i put this in my answer..?

 

[ousamah112]

how do i put this in my answer..?

you can write about length of some fish or size of animals... like for certain fish small size is advantageous as they can avoid being attacked by predators...etc

 

[angelgirl:)]

how do i put this in my answer..?

in ur answer u dont need to explain it in detail i guess...u just have to mention that phynotypic variation can be either continues or discontinuos and is the resuld of interaction with the variation in genotype and the enviorment..

 

[angelgirl:)]

in ur answer u dont need to explain it in detail i guess...u just have to mention that phynotypic variation can be either continues or discontinuos and is the resuld of interaction with the variation in genotype and the enviorment..

and then continue rest of ur own answer..

 

[user]

Explain why variation is important in selection;

1. ref. continuous / discontinuous variation ;​

2. genetic / inherited variation ;​

3. variation in phenotype / characteristics / AW ;​

4. (can be due to) interaction of genotype and environment ;​

5. e.g. of characteristic that influences survival ;​

6. ref. intraspecific competition / struggle for existence ;​

7. those with favourable characteristics survive / AW ;​

8. pass on favourable characteristics to offspring ;​

9. those with disadvantageous characteristics die ;​

Variation means the presence of different characteristics or traits. There will be genetic variation within the population. The interaction of the genotype and environment results in phenotypic variation. Phenotypic variation may be continuous or discontinuous. Variation results in different survival rates of organism, which ultimately leads to reproductive success or failure. Organisms with most suitable traits and those that are best adapted to a stable environment have a survival advantage. Those surviving better get more chances of reproduction. They pass on their favourable characteristics to their offsprings and their number further increases. Whereas, those with disadvantageous characteristics, cannot survive, and die.

hassam: you needed help with this
angelgirl:): is it correct now?

 

[angelgirl:)]

Explain why variation is important in selection;

1. ref. continuous / discontinuous variation ;​

2. genetic / inherited variation ;​

3. variation in phenotype / characteristics / AW ;​

4. (can be due to) interaction of genotype and environment ;​

5. e.g. of characteristic that influences survival ;​

6. ref. intraspecific competition / struggle for existence ;​

7. those with favourable characteristics survive / AW ;​

8. pass on favourable characteristics to offspring ;​

9. those with disadvantageous characteristics die ;​

Variation means the presence of different characteristics or traits. There will be genetic variation within the population. The interaction of the genotype and environment results in phenotypic variation. Phenotypic variation may be continuous or discontinuous. Variation results in different survival rates of organism, which ultimately leads to reproductive success or failure. Organisms with most suitable traits and those that are best adapted to a stable environment have a survival advantage. Those surviving better get more chances of reproduction. They pass on their favourable characteristics to their offsprings and their number further increases. Whereas, those with disadvantageous characteristics, cannot survive, and die.

hassam: you needed help with this
angelgirl:): is it correct now?

yes absolutly...

 

[hassam]

yea thanks user

 

[user]

angelgirl:) hassam alphabravocharlie

firstly, assalamoalaikum wr wb to u all..

Well you people asked about describing graphs.
Just remember one thing.. ‘describing a graph’ is the best part cuz u just have to tell what the graph shows and u need not worry about why it is so [unless they ask you to explain]...so u get 3-4 marks for free
Now remember these points when describing a graph
-state the general trend—increases/decreases as **** increases

-give atleast 2 readouts from your graph to support your statement

-one important point is, mention the units. Despite the fact that mark schemes say [ignore units], there are places where they say condone if no units...so better you ALWAYS write the units

-state any points/exceptions that do not fit the general trend

-sometimes...it’s like the curve is divided into two sets...like for the first few readings it decreases less steeply and for the next few..it’s more steeper or vice versa....include this point in your answer, and use data to support your answer....

-If the question mentions ‘with reference to the graph/figure..’ note that u might lose marks if you don’t do so. Read the question carefully..

P.S. This is all based on my understanding, after I did pastpapers, and hope it helps you all..
Remember me in your prayers..
O Allah give us all success in both worlds, Aameen..!!

 

[Asha Tabassum]

can anyone post the definations for Biology A2... or can anyone provide me with any link of biology definations?????????