Edexcel BIOLOGY Doubts!!!!

[guMnam]

research type q ?? :S

didnt understand.. are u talking abt the paper 5 scientific article thing ??

[~ Miss Relina ~]

research type q ?? :S

didnt understand.. are u talking abt the paper 5 scientific article thing ??

no paper 3 the second question in each recent past paper

[guMnam]

hmm.. leme chek..

[~ Miss Relina ~]

guuuuuuuuuuuuuuys really need to know how dou cope with the second questions in the  unit 3 practical and investigation skills
waiting for ur replies Thanks in advance

[Book lover22]

Salams

I also have a small confusion with da following: Please mention where they are found n their definitions:

a. Baroreceptors
b. Stretch receptors
c.Chemoreceptors

is a and b the sam thing?? 

[guMnam]

Salams

I also have a small confusion with da following: Please mention where they are found n their definitions:

a. Baroreceptors
b. Stretch receptors
c.Chemoreceptors

is a and b the sam thing?? 

sterchreceptors are receptors in the walls of the heart which respond to the streching of the walls of the heart as the heart fills with blood and then send impulses to the cardio vascular centre in the brain
chemoreceptors are receptors which respond to the presence of difrent chemicals...eg they are sensitive to the level of co2 and pH of the blood in the hind brain.. in carotid bodies and in the aortic arch (i.e in the aortic arch)
baroreceptors are sensors tht are sensitive to presure... found in sinuses(thts all we need to noe.. prolly they are present at other locations as well) of the carotid arteries in the neck and are important in the feedbak control of the heart rate.

hope thts all u needed to noe

[guMnam]

and as u can see.. chemo receptors and the baro receptors are two diferent things but are found near by

[Book lover22]

Thankusss!! now i understand!

But wats da diff between baro receptors n stretch receptors....r baroreceptor a kind of stretch receptor???

[Blizz_rb93]

Each time the heart beats, the atria contract first and then the ventricles contract. Explain how this sequence of events is coordinated?

[guMnam]

dont u guys read the text book ?? ^this thing is fully explained in the edexcel a2 biology book...

if u want ill explain the whole thing here in short but its beter if u have a look at it urself beter understandig

[guMnam]

independent variables and dependent variables... .. wat are they i mean the diference ??

[Blizz_rb93]

dont u guys read the text book ?? ^this thing is fully explained in the edexcel a2 biology book...

if u want ill explain the whole thing here in short but its beter if u have a look at it urself beter understandig

i dont have the A2 edexcel book and i dont take A2, im taking the AS edexcel biology

[guMnam]

@blizz

umm mayn are u sure u need to noe the mechanism for as ?? :S

any ways.. u noe tht the atrial systole forces blood into the ventricles and then the ventricular systole forces blood out to the aorta.. and the pulmonary artery.. this is known as the intinsic rythem of teh heart..including the diastole part....

this is all u need to noe for the AS i think.... if u have seen any q like this in any pastpaper then do let me noe caz the controling of the heart beat by nervous system is in A2

[MKh]

During an investigation or experiment, the independent variable is controlled by the experimenter.The dependent variable is measured to give the results. For example, in the Daphnia experiment in AS, the independent variable is caffeine concentration because it is controlled by the experimenter and the dependent variable is the intensity of red colouration (absorbance) because it is the one that is measured to give the results. The dependent factor depends on the independent variable....hope it helps....

[guMnam]

During an investigation or experiment, the independent variable is controlled by the experimenter.The dependent variable is measured to give the results. For example, in the Daphnia experiment in AS, the independent variable is caffeine concentration because it is controlled by the experimenter and the dependent variable is the intensity of red colouration (absorbance) because it is the one that is measured to give the results. The dependent factor depends on the independent variable....hope it helps....

Thanks
+rep