CHEM AND BIO HELP AND TIPS HERE

[Ghost Of Highbury]

@ Burhan.arshad - OK PROBABLY THIS IS THE ANSWER..

Transition metal carbonates decompose faster because theyre not stable when heated.

the transition metals carbonates in the list are of zinc and copper.

Zinc is more reactive than copper, thus copper carbonate will get decomposed the fastest. = 25seconds = U

Next will be zinc = Z = 50seconds

Our of calcium magnesium and sodium, the reactivity is this like this-> Sodium, calcium , magnesium ...(sodium being the most reactive)

thus magnesium carbonate will decompose after copper and zinc...Magnesium carbonate = 100seconds = V

Then will be calcium carbonate = 300 seconds = X

and last will be of the most reactive metal sodium carbonate = Y = more than 1000seconds.

[Raywin]

What is quorn and mycroprotien ? :S

[soulreapr_ninja]

I'm pretty sure we don't need to know anything about the brain (except for the fact that it's part of the central nervous system with the spinal cord)? Unless you're taking O-Level, which you're not, as far as I know?

its bettrr to know the basics juzt in case
Medulla: controls heartbeat and breathing
Cerebral cortex: controls intelligence n motor action
Cerebellum: balance of body is monitored
Pituitary gland: secretes the hormones MSH and ADH

thats it

[nid404]

http://www.srepapmaxeeeerf.org/O%20Level/Chemistry/CIE/2007%20Jun/5070_s07_qp_2.pdf


this is the link to paper.....
please explain Q7c and 11d

The more reactive metals take longer to dissociate.

Reactivity series from most reactive to least reactive
Potassium
Sodium
Calcium
Magnesium
Aluminium
Zinc
Iron
Tin
Lead
Copper
Silver
Gold
Platinum

The ones in bold are of our concern
Least time was for U.25sec. The least reactive metal among the ones used is Copper
The next was Z 50sec. This would be Zinc
In the same way...you're just moving up the series
Then V would be Magnesium
X would be calcium
Y would be sodium

Hope you got that.

[thenewkid™]

they are both SCP (single cell protiens)

[Raywin]

they are both SCP (single cell protiens)

Thx..

[soulreapr_ninja]

Can any1 pls xplain me TRANSLOCATION the whole concept, including its source and sink in difrent conditions

[Moonlyte]

What is quorn and mycroprotien ? :S

i just realised that quorn is the brand name of mycoprotein (so basically they are the same thing). mycoprotein is made by the mould fungus. Mycoprotein is a substitute for meat (so its popular among vegetarians).

Single cell protein (SCP) is made by yeasts.

[Raywin]

Can any1 pls xplain me TRANSLOCATION the whole concept, including its source and sink in difrent conditions

Translocation is the movement of the finished food products from the leaves (source) to the rest of the plant for eg: Roots(sink) and yeah these finished products travel through the Phloem. Oh and in the early stages of the plant the SOURCE is the cotyledons and the SINK is the roots (germination stage). Yeah this is all u need to know..  

[Raywin]

i just realised that quorn is the brand name of mycoprotein (so basically they are the same thing). mycoprotein is made by the mould fungus. Mycoprotein is a substitute for meat (so its popular among vegetarians).

Single cell protein (SCP) is made by yeasts.

Ohh.. thanks..

[Syed Kazim]

Can any1 pls xplain me TRANSLOCATION the whole concept, including its source and sink in difrent conditions

Xylem tissue tansports water - dead xylem cells form tubes through which water is drawn. The walls of xylem tubes are waterproofed with a substance called lignin.

Phloem tissue transports food in flowering plants. Living phloem consists of tubes of sieve cells and companion cells.

[Moonlyte]

Ohh.. thanks..

no problem

[saleemsamer]

Hey guys
i kno i have mark schemes but can some1 plz give me a model answer for O/N 05 p3 q6 c (biology) PLZ
it says ref. and ref. i kno wat it means but i wud like a full answer
thx in advance

some1 plz i rely need this concept for othr questions

[Syed Kazim]

Xylem tissue tansports water - dead xylem cells form tubes through which water is drawn. The walls of xylem tubes are waterproofed with a substance called lignin.

Phloem tissue transports food in flowering plants. Living phloem consists of tubes of sieve cells and companion cells.

Transport of water and minerals

• Root hairs absorb water from the soil by osmosis; mineral ions are actively transported into the root
• Water passes through the root tissue into the xylem by osmosis
• Water travels through the xylem of the root and stem in unbroken columns - the transpiration system
• Water moves through the xylem of the leaf stalk and veins of the leaf
• Water evaporates into the large air spaces within the leaf - the air spaces are saturated with water vapour
• The concentration of water vapour in the atmosphere is lower that that in the air spaces - water vapour diffuses from the leaf through the stomata; the process is called transpiration
• Water lost by cells through evaporation is replaced with water drawn though the cells by osmosis - cells next to the xylem draw water from the xylem by osmosis

Plants lose water through transpiration and gain water through its uptake by the roots. If the loss is greater than the gain then the stomata close and transpiration is reduced. If the loss continues then the cells of the plant lose turgor (rigidity) and the plant wilts.

Different factors increase the rate of transpiration:

• temperature
• wind velocity
• light intensity

Humidity decreases the rate of transpiration.

[K_M]

guys i'm so screwed for bio tomorrow i spent most of today studying for accounting and i'm REALLY not ready for bio.. like i understand everything, but i haven't really memorized specific topics well.. and i've only done 2 past papers! i still need to review more for accounting and BOTH are tomorrow morning so i have no time to study in the morning and and like 2 or 3 more hours max tonight.
what do i do??? someone help please

Heyy go over all the plant stuff because i think therell be a question on plants since nothing came in paper 6. do ecology, genetics, excretion, reproduction. I think the other stuff is pretty easy but do these things for sure!