IGCSE Edexcel Biology - Paper 1

Well,I put because the sperm duct is on the outside of body it is easier to access and oviduct is inside female body so much harder to operate

Reply 342

Ventilation occurs in lungs

Reply 343

Original post by Foreboding

For lake C, I said the result could have been an anomaly and that the depth of the secchi disk does not necessarily correlate to pollution precisely. Ie. There could be less phosphate but more alkaline growth

U mean algae growth?

Reply 344

Original post by UltimateLad1

Guys can we try predict what will come up in 2B?

Well,probably cuz yield is supposed to be in paper2 and a lot of things didn't come up like natural selection,fish farming,selective breeding,response

Reply 345

helloitsmee

Original post by Zakariyam10

Well,probably cuz yield is supposed to be in paper2 and a lot of things didn't come up like natural selection,fish farming,selective breeding,response

The thing about phosphate levels and fish, wouldn't you roughly call it related to fish farming? I had to do so much guessing with that question :frown:

Reply 346

PalwashaAyubb

2

Guys if you look at the grade boundaries for the past few years we can see that A is 102-120 Not more than that and it has stayed like this for a couple of years and seeing hpw hard and confusing the paper was,many messed up in it so they wont take it above 120 atleast so if you get atleast 70/120 in paper 1 and atleast 50/60 in paper 2 you are most likely to get an A cause then that makes 120/180 so hope for the best and just stop thinking about paper 1 and do your best in paper 2 cause now we know how unexpected questions can come so just like do the markschemes for paper 2 too :smile:

Reply 347

username1392487

12

But one vas deferens so the two proximal sperm ducts collide to form it. Any hoo a vasectomy is much less invasive all you need to do is open the scrotum where as you would need to open a woman's abdomen making it more invasive and prone to complications

Reply 348

username1392487

12

Original post by helloitsmee

The thing about phosphate levels and fish, wouldn't you roughly call it related to fish farming? I had to do so much guessing with that question :frown:

Good question it relates to eutrophication which we are used to seeing in terms of nitrate fertiliser but the logic is transferable i.e. Depletion of O2 levels

Reply 349

Braineater79

what was the answer about heart attacks and why they occur when there is less oxygen in the body?

Reply 350

janster111

OP

4

Loool #IGCSEbiology on Twitter is hilarious. You guys must check it out hahaha

Reply 351

Rm543

I said one measurement in April was above the safety line (I.e. So not safe) but the other measurement in April was 1m below it (so therefore safe)

Reply 352

trabajador

7

What mark do people reckon they've got?

Reply 353

PalwashaAyubb

2

for this i dont know i wrote something about soil erosion and too much rain in april causing soil erosion so the river might have been filled with other stuff i dont know lol

Reply 354

PalwashaAyubb

2

Original post by trabajador

What mark do people reckon they've got?

i dont i hope i get more than 70 in paper 1 so atleast if i get 50 in the other paper it will make up to An A as seeing the past few years markschemes

Reply 355

helloitsmee

Original post by geekface98

Good question it relates to eutrophication which we are used to seeing in terms of nitrate fertiliser but the logic is transferable i.e. Depletion of O2 levels

I've never done that chapter since I'm self-teaching haha, but I wrote loads for that question and was on about competition for oxygen in the pond, which is usually a confined area. Is that what you mean?

Reply 356

Ngi

4

Hi, I am doing edexcel double award science as private candidate I think I toalky messed up yesterday paper so want to know if I do good in physic and chemistry is it ok? I mean will they combine the marks and give the result or seperetly. Can any one please help !! And what is the c grade for yesterday's paper ?

Reply 357

Foreboding

Original post by helloitsmee

I've never done that chapter since I'm self-teaching haha, but I wrote loads for that question and was on about competition for oxygen in the pond, which is usually a confined area. Is that what you mean?

I think the main to point to get across is this:
-> phosphate levels are high in the lake
-> encourages growth of algae. Algal 'blooms' form
-> blocks out light for underwater plants so they cannot photosynthesise.
-> underwater plants eventually die as a result.
-> the algae eventually die as well
-> decomposers such as bacteria begin to decompose the dead plants and algae
-> they respire more often, using up oxygen in the water
-> this makes the water anoxic.
-> fish numbers decrease because they cannot get the oxygen they need for aerobic respiration

Reply 358

janster111

OP

4

Original post by Foreboding

I think the main to point to get across is this:
-> phosphate levels are high in the lake
-> encourages growth of algae. Algal 'blooms' form
-> blocks out light for underwater plants so they cannot photosynthesise.
-> underwater plants eventually die as a result.
-> the algae eventually die as well
-> decomposers such as bacteria begin to decompose the dead plants and algae
-> they respire more often, using up oxygen in the water
-> this makes the water anoxic.
-> fish numbers decrease because they cannot get the oxygen they need for aerobic respiration

Yeh that's what I put

Reply 359

Foreboding