BIO Doubts..here..everyone!!

[Xenarra]

Can sumone tell me the process of reproduction in bacterias plzz..???
thnks in advnce..!!

Hey,
Ok, reproduction in bacteria. here it goes: (the links to the diagrams are at the bottom)

Monera (bacteria) reproduce by binary fission. This is asexual because only one organism has ability to reproduce.
ok, so one cell makes a copy of the DNA so now there are two DNA's in one cell.....the cell starts to divide and then separates. Each DNA in each cell....so now there are two of them....remember this is happening in bacteria....reading this maybe sound like a slow process but this happens really fast ..maybe keeps on splitting every 20 mins.

Just extra:
Binary fission also happens in protozoa.

Fungus, namely yeast, reproduce by budding. Other fungus reproduce by the means of hyphae and mycellium and all.

here are the links to the diagrams:
For binary fission:
http://www.google.com/imgres?imgurl...page=1&ndsp=14&ved=1t:429,r:1,s:0&safe=active
you really dont have to learn the labels and all..but if you want to you can.

for yeast budding:
http://www.google.com/imgres?imgurl...d=1t:429,r:5,s:12&biw=800&bih=509&safe=active

Also, you should be knowing how viruses reproduce the hyphae thing, sporangiums
Don't hesiste to ask anything, if i have mistakes please correct me

BR,
Xenarra

 

[Xenarra]

guyz, i have question :
I know we can`t say reaction time decreases for increased alcohol consumption but can we say reaction time slows down cause it was in this mark scheme: variant 1, q2(c)(iii) ---> (http://www.xtremepapers.me/CIE/Cambridg ... 7_ms_3.pdf)
for this past paper --> variant 1, q2(c)(iii) ---> http://www.xtremepapers.me/CIE/Cambridg ... 7_qp_3.pdf
I am really confused if this is what the mark scheme meant for us to write (reaction time slows down)
thnx for taking ur time to actually read all of this

Hey,

Ok the mark scheme said reaction time slows down...it IS right though...reaction time time decreased kind of implies that the persons reaction time reduced which is totally different from SLOWING down. So mainly it means the time taken for the impulses to be carried is slow (speed is reduced) if you right DECREASED then its like the impulses being carried is decreased, which is not right because number of impulses can't decrease.

hopefully i answered you question and did not make it more confusing , lol

BR,
Xenarra

 

[Xenarra]

Hey,

I have a major doubt about the clotting of blood when there is a cut, you know the fibrinogen, platelets stuff...can someone please define this in the easiest way possible..because i seem to get muddled up every time i look at the book :/

BR,
Xenarra

 

[Xenarra]

Hey,

This is what I know about the blood clotting process...although i am sure it is not right coz it seems to too small:
Enzymes from platelets changes soluble fibrinogen into insoluble fibrin. Firbrin forms a net and traps blood making a blood clot.. phagocytes arrive and engulf hr pathogen. The clot becomes a scab and protect wound until skin heals.

BR,
xenarra

 

[ziasha123]

HHHEEYYY guys i m new to this .. so would any1 have trouble explaining what all this actually is ? :lol: :good:

 

[Xenarra]

HHHEEYYY guys i m new to this .. so would any1 have trouble explaining what all this actually is ? :lol: :good:

Hey,

most probably you are from IGCSE and giving the exam this session...because you clicked on the cambrigdge IGCSE tab...WELCOME! We discuss doubts here...in this topic its for Biology...you can find other topics too! Browse around and you will get used to it.

BR,
Xenarra

 

[ziasha123]

ohhh thats cool !!! yeah i m taking IGCSE.. i have my biology paper 3 tmrw ... i guess so do u all .. i dn't really have doubts though i would like to answer some ...
so here does every1 knw each other or they just knw because of the doubt clarification system

 

[ziasha123]

Hey,

I have a major doubt about the clotting of blood when there is a cut, you know the fibrinogen, platelets stuff...can someone please define this in the easiest way possible..because i seem to get muddled up every time i look at the book :/

BR,
Xenarra

It simple ... just take it as this ... u get cut and u start to bleed .. when ur blood come in contact with the air it triggers with the help of platelets for ur blood to thicken and stop bleeding
in detail : these platelets release Thromobokinase which converts soluble proteins (fibrinogen) in the plasma into insoluble fibrinogen.... this forms a meshwork an which the platelets and RBC etc get entangled thats it

 

[burndtjamb]

Hey,

I have a major doubt about the clotting of blood when there is a cut, you know the fibrinogen, platelets stuff...can someone please define this in the easiest way possible..because i seem to get muddled up every time i look at the book :/

BR,
Xenarra

It simple ... just take it as this ... u get cut and u start to bleed .. when ur blood come in contact with the air it triggers with the help of platelets for ur blood to thicken and stop bleeding
in detail : these platelets release Thromobokinase which converts soluble proteins (fibrinogen) in the plasma into insoluble fibrinogen.... this forms a meshwork an which the platelets and RBC etc get entangled thats it

Also remember that clotting takes place in the presence of Calcium, that's another reason in addition to bones why it's so important in your diet.

 

[AStarHunter]

Hey,

I have a major doubt about the clotting of blood when there is a cut, you know the fibrinogen, platelets stuff...can someone please define this in the easiest way possible..because i seem to get muddled up every time i look at the book :/

BR,
Xenarra

It simple ... just take it as this ... u get cut and u start to bleed .. when ur blood come in contact with the air it triggers with the help of platelets for ur blood to thicken and stop bleeding
in detail : these platelets release Thromobokinase which converts soluble proteins (fibrinogen) in the plasma into insoluble fibrinogen.... this forms a meshwork an which the platelets and RBC etc get entangled thats it

Actually, it converts soluble finbrinogen into insoluble fibrin

 

[igcse2011]

Could anyone help me ?
-To describe the role of fungus Penicillium in the production of antibiotic penicillin ?
-Why antibiotics kill bacteria but not viruses ?
-Role of hormones in controlling the menstrual cycle which includes FSH, LH,progesterone and oestrogen
-Implications to a species of self and cross pollination.

 

[ziasha123]

yeah sry .....wrng... my mistake

 

[xIshtar]

Hey,

I have a major doubt about the clotting of blood when there is a cut, you know the fibrinogen, platelets stuff...can someone please define this in the easiest way possible..because i seem to get muddled up every time i look at the book :/

BR,
Xenarra

It simple ... just take it as this ... u get cut and u start to bleed .. when ur blood come in contact with the air it triggers with the help of platelets for ur blood to thicken and stop bleeding
in detail : these platelets release Thromobokinase which converts soluble proteins (fibrinogen) in the plasma into insoluble fibrinogen.... this forms a meshwork an which the platelets and RBC etc get entangled thats it

Actually, it converts soluble finbrinogen into insoluble fibrin

Correct, also useful to note that the enzyme released is a protease.

Also useful to note, that once the mesh forms, the capillaries basically reduce themselves in size so as to reduce blood traffic and thus, blood loss

 

[angel786]

hye
.can any one plz tell me the role of enzymes in biological washing powder and in food industry???

 

[xIshtar]

Could anyone help me ?
-To describe the role of fungus Penicillium in the production of antibiotic penicillin ?
-Why antibiotics kill bacteria but not viruses ?
-Role of hormones in controlling the menstrual cycle which includes FSH, LH,progesterone and oestrogen
-Implications to a species of self and cross pollination.

Well. Basically, viruses are not like normal living organisms, infact, they do not begin to act like living organisms until they are inside a host cell. Once they are inside the host cell, they take over the cell and instruct it to replicate the viruses.
On another note, the common cold virus is incurable in humans because our memory cells do not recognise it due to a slight change in it's outer protein coat.
Oestrogens are the female hormones, which lead to the development of secondary female characteristics, and the hormones which eventually play a role in the menstrual cycle.
Oestrogen causes the thickening of the uterus lining, in preparation for the implantation of a zygote. It also prevents the further release of eggs or FSH.

FSH is basically follicle stimulation hormone. It does what it says.

Progesterone is the hormone secreted, which maintains the uterus lining during pregnancy.

As for the implications of self and cross species pollination:

Self pollination:
Can lead to extinction.
Is quicker.
Has a higher chance of success.
Allows for the passing on of advantageous characteristics.

Cross pollination:
Allows for advantageous characteristics to be passed on, due to either natural selection or survival of the fittest.
Has a smaller chance of success, as pollen has to be carried.
May take longer.
Allows for the species to adapt and carry on living due to survival of the fittest.

I suggest reading up on Darwin's theory.

 

[xIshtar]

hye
.can any one plz tell me the role of enzymes in biological washing powder and in food industry???

Biological washing powders contain proteases and lipases. They break down proteins and fats, ie, blood stains and grease. Not much else to say.

In food industry, all that springs to mind at this moment in time is pectinase and rennin.

Rennin is an enzyme added during the manufacturing of cheese, which makes it coagulate more. (If you don't know what this means, just say )

Pectinase is the enzyme which is used for extracting fruit juice. Basically, pectin itself is present in fruits such as oranges, as it makes the cell walls stick together. Pectinase breaks down this bond, and thus makes juice extraction easier.

If you have any specific examples, I'd be glad to help

 

[igcse2011]

In biological washing powders enzymes are used such as :
Protein is broken down by protease -Helps in removal of blood stains.
Fats to fatty acids and glycerol by lipase -To remove greasy stains.

In food industry :
Pectin is broken down by Pectinase - A fruit juice contains a lot of pectin.
Protease breaks down protein to polypeptide and amino acids - Easier for young babies to absorb food.
Amylase digests starch to maltose -For making syrup.
Glucose to fructose by isomerase- Can get a sweet taste with less sugar.

 

[freakedout]

Okkay I have a doubt !!
describe the sites of
production and the roles of
oestrogen and progesterone
in
- the menstrual cycle
- pregnancy

anyone??

 

[angel786]

hye
.can any one plz tell me the role of enzymes in biological washing powder and in food industry???

Biological washing powders contain proteases and lipases. They break down proteins and fats, ie, blood stains and grease. Not much else to say.

In food industry, all that springs to mind at this moment in time is pectinase and rennin.

Rennin is an enzyme added during the manufacturing of cheese, which makes it coagulate more. (If you don't know what this means, just say )

Pectinase is the enzyme which is used for extracting fruit juice. Basically, pectin itself is present in fruits such as oranges, as it makes the cell walls stick together. Pectinase breaks down this bond, and thus makes juice extraction easier.

If you have any specific examples, I'd be glad to help

thanks :Yahoo!:

 

[angel786]

In biological washing powders enzymes are used such as :
Protein is broken down by protease -Helps in removal of blood stains.
Fats to fatty acids and glycerol by lipase -To remove greasy stains.

In food industry :
Pectin is broken down by Pectinase - A fruit juice contains a lot of pectin.
Protease breaks down protein to polypeptide and amino acids - Easier for young babies to absorb food.
Amylase digests starch to maltose -For making syrup.
Glucose to fructose by isomerase- Can get a sweet taste with less sugar.

thanks :Yahoo!: