BIO Doubts..here..everyone!!

[narutogirl]

i have a question, about the food chain
do we we include the sun when we draw it cuz our teacher said that but in the syllabus they specifically said start with a producer they didn't mention anything about the sun :/

Start with the producer.

r u sure because i looked up some sites and they said start with the sun, and my teacher once subtracted a mark because i didn't add the sun at the beginning of the food chain? it came up in a question but i don't remember which :/

 

[shan5674]

hey

I'm new here and i was going through some of your doubts and answers, they were really helpful thanks everyone

I also would like to clear one of my doubts, i cant understand how to draw a virus with all its structures like the DNA, the protein coat, the envelope and capsomere, does anyone know how to draw them coz i came across a question where they wanted us to draw the virus and the marking scheme had all of the above mentioned in it, im confused, help plzzz

Hey,
This is what i kind of drew it like:
http://www.google.com/imgres?imgurl...d=1t:429,r:3,s:49&biw=800&bih=509&safe=active

you have to know all three of these....hopefully this helps

BR,
xenarra

Heyy thanks a bunch, it really helped :Yahoo!:

 

[Xenarra]

hey,

What do they mean by natural method of contraception?? And does tbectomy and vasdeference come under mechanical method??

BR,
Xenarra

 

[shan5674]

hey,

What do they mean by natural method of contraception?? And does tbectomy and vasdeference come under mechanical method??

BR,
Xenarra

Natural method really means the women monitoring her menstrual cycle and keeping track of when she is ovulating and making sure not have intercourse during the time.

and about the vasectomy, nope its not mechanical method, its a surgical method Mechanical methods usually include the use of condoms and the cap

hope this helps

 

[Xenarra]

hey,

What do they mean by natural method of contraception?? And does tbectomy and vasdeference come under mechanical method??

BR,
Xenarra

Natural method really means the women monitoring her mensuration cycle and keep track of when she is ovulating and making sure not have intercourse during the time.

and about the vasectomy, nope its not mechanical method, its a surgical method Mechanical methods usually include the use of condoms and the cap

hope this helps

got it

 

[narutogirl]

i was wondering if what i wrote is enough to describe sickle cell anemia :/

Sickle cell anemia is the result of a faulty replication during meiosis in which there is a disorder in the sequence of the amino acid in the hemoglobin molecule inside a red blood cell.
they are rapidly destroyed as the hemoglobin inside the RBC form fibers that gets tangled up and make the cell into a sickle shape.
The aren't flexible so they could get stuck inside blood capillaries, which is very painful and life threatening as this increases the blood pressure so it is able to push the RBCs through these fine capillaries. A damage in the inner walls of the blood vessels could be very painful as this resists the blood flow. and finally they carry a low concentration of oxygen so these people usually die of severe anemia before they reach the age of marriage.

oh and in countries where there is malaria people who have heterozygous of these sickel cells are the only ones that are able to survive..

is that enough or should i know something more ^_^"

 

[Xenarra]

i was wondering if what i wrote is enough to describe sickle cell anemia :/

Sickle cell anemia is the result of a faulty replication during meiosis in which there is a disorder in the sequence of the amino acid in the hemoglobin molecule inside a red blood cell.
they are rapidly destroyed as the hemoglobin inside the RBC form fibers that gets tangled up and make the cell into a sickle shape.
The aren't flexible so they could get stuck inside blood capillaries, which is very painful and life threatening as this increases the blood pressure so it is able to push the RBCs through these fine capillaries. A damage in the inner walls of the blood vessels could be very painful as this resists the blood flow. and finally they carry a low concentration of oxygen so these people usually die of severe anemia before they reach the age of marriage.

oh and in countries where there is malaria people who have heterozygous of these sickel cells are the only ones that are able to survive..

is that enough or should i know something more ^_^"

Well this is wayy much more than wat my notes say...so yeah this is pretty good...although i have a feeling they wont ask this :/

 

[Xenarra]

Hey,

Can someone write something about ecology because i don't think i studied enuf from it :/
Also something about the penicillin,fermentation and lactobacillus bulgaricus and streptococus thermophilus.
they seem hard.

BR,
Xenarra

 

[narutogirl]

ya same problem here..and if anyone is kind enough can you write the steps we must know for genetic engineering :/

 

[shan5674]

lol i haven't studied much from that chapter either :/ and also, the sewage treatment part :/ oh and one more, i dont get the population graph thing :/ about the lag and log phase :/

help plzz

 

[Xenarra]

ya same problem here..and if anyone is kind enough can you write the steps we must know for genetic engineering :/

Hey,
this is what my notes say:

The technique used to artificially transfer genes from one organism to anohter is known as genetic engineering.
The basic steps in gene cloning are as follows:
-identify the required gene in the relevant DNA strand
-Isolate the gene by cutting up the chromose to release the gene.A pair of enzymes called restricion enzymes acts as a molecular scissor do this job.
-extract a vector-a vectot is the vehicle that is used to carry the forign gene.
-open up this vector by using restriction enzymes.
-insert the gene into the opened vector.
-insert the modified or recombinant vector into the suitable host cell-this is called transofrmation.
-Grow this in a nutrient meduim and let is multiply.


Production of insulin:
-identify human gene
-use pair of restriction enzymes to cut insulin gne from the DNA srand, producing a DNA fragment with sticky ends.
-Extract plasmids from the bacterium and use vectors-open up each plasmid with a pair of restriction enzymes, producing sticky ends on it that complement this on the insulin genes.
-insert the human insulin gene into each cut using enzymes ligase to ligate the gene.
-intorduce the recombinant plasmid into the host bacterium
-grow the transformed bacteria using specific culture media.
-harvest the bacteria from the culture medium in each fermentor and extract insulin.

this is what it says in my note...it has diagrams but i can't post it.

BR,
Xenarra

 

[Xenarra]

lol i haven't studied much from that chapter either :/ and also, the sewage treatment part :/ oh and one more, i dont get the population graph thing :/ about the lag and log phase :/

help plzz

Hey,
the graph you are talking about is called the "Sigmoid Growth Curve".
In our syllabus it usually comes along with the yeast production...the diagram kinda sums it all up.
http://mesosyn.com/mental1-12c2.gif

hope it helps

BR,
Xenarra

 

[Xenarra]

ya same problem here..and if anyone is kind enough can you write the steps we must know for genetic engineering :/

Hey,
this is what my notes say:

The technique used to artificially transfer genes from one organism to anohter is known as genetic engineering.
The basic steps in gene cloning are as follows:
-identify the required gene in the relevant DNA strand
-Isolate the gene by cutting up the chromose to release the gene.A pair of enzymes called restricion enzymes acts as a molecular scissor do this job.
-extract a vector-a vectot is the vehicle that is used to carry the forign gene.
-open up this vector by using restriction enzymes.
-insert the gene into the opened vector.
-insert the modified or recombinant vector into the suitable host cell-this is called transofrmation.
-Grow this in a nutrient meduim and let is multiply.


Production of insulin:
-identify human gene
-use pair of restriction enzymes to cut insulin gne from the DNA srand, producing a DNA fragment with sticky ends.
-Extract plasmids from the bacterium and use vectors-open up each plasmid with a pair of restriction enzymes, producing sticky ends on it that complement this on the insulin genes.
-insert the human insulin gene into each cut using enzymes ligase to ligate the gene.
-intorduce the recombinant plasmid into the host bacterium
-grow the transformed bacteria using specific culture media.
-harvest the bacteria from the culture medium in each fermentor and extract insulin.

this is what it says in my note...it has diagrams but i can't post it.

BR,
Xenarra

and heres a diagram i found quite similar to the one in my notes http://publications.nigms.nih.gov/thenewgenetics/images/ch2_recombinant.gif

 

[shan5674]

lol i haven't studied much from that chapter either :/ and also, the sewage treatment part :/ oh and one more, i dont get the population graph thing :/ about the lag and log phase :/

help plzz

Hey,
the graph you are talking about is called the "Sigmoid Growth Curve".
In our syllabus it usually comes along with the yeast production...the diagram kinda sums it all up.
http://mesosyn.com/mental1-12c2.gif

hope it helps

BR,
Xenarra

It helped, thanks

 

[shan5674]

Oh by the way, i got another doubt

Can u define "active transport" for me please- Is my definition right? (Active transport is when special carrier proteins on the membrane of a cell picks up substances and transports them from one side of the cell to the other) :S coz last time i came across two past papers that asked the same question but one had a completely different definition that was something like the definition for diffusion and one was the same as mine, so im confused how do i know when to use which definition? and is my definition right?

I also lost marks in my mock exam for writing down that definition so i really dont know :/

 

[Divalicious]

Hey,

Can someone write something about ecology because i don't think i studied enuf from it :/
Also something about the penicillin,fermentation and lactobacillus bulgaricus and streptococus thermophilus.
they seem hard.

BR,
Xenarra

Ecology isn't hard, it's just really long. First there's food chains and webs, you gotta know things like producers and primary/secondary consumers.
Then there're pyramids of biomass/energy, I never really focused on those, they don't come in exams alot.
There's also water/nitrogen/carbon cycles, if you understand those they're easy to write. And finally there're fertilizers, pesticides, weed-killers. Those might be the hardest, since they require you to memorize some advantages and disadvantages. I know I'm just mentioning headlines, but I'm gonna write some summarized points on each once I re-read them off my notes again xD
~And about lactobacillus and streptococcus, I don't think you have to memorize the names. You just have to know that they're bacteria added to milk, then they respire anaerobically on milk lactose to give lactic acid, that's acidic and reduces milk's pH, denaturing the milk proteins and causing it to coagulate and become thick. [Books mention that milk is heated to 90 C then cooled to kill bacteria before the whole procedure, and 'homogenized' to make the fat content the same in the whole milk. Boring points that books use to screw up interesting topics xD]
--Wow I'm really loving this thread, re-writing things I learnt makes me remember them more and I learn alot from reading what others write. Specially since I like reading things off the computer than checking some boring notes-books xD --

 

[Xenarra]

Hey,

Ok heres a summary of what i studied about reproduction in plants:

Feamle part is called carpel, it contains style, stigma and ovary
Male part is called stamen, it contains anther and filament.Anther has the pollen grains.

Pollination is the transfer of pollen from anther to stigma.
Self-pollination is when anther and stigma are from same flower or different flowers on the SAME plant.
Cross pollination happens when the anther and stigma are in flowers on different plant of the SAME species.
pollination happens by wind or insects.

Fertilisation:
Stigma produces sugary fluid on to which the pollen grain falls on to. The pollen grain releases the male gamete and it travels down the pollen tube. It reaches the micropyle and enters the ovule and fuses with the female gamete.
As soon as fertilisation occurs, the petals fall off, the sepal fall off, the ovule coat becomes the pericarp and the female gamete coat becomes the testa. Fruit formed!

Correct me please!

BR,
Xenarra

 

[Xenarra]

Oh by the way, i got another doubt

Can u define "active transport" for me please- Is my definition right? (Active transport is when special carrier proteins on the membrane of a cell picks up substances and transports them from one side of the cell to the other) :S coz last time i came across two past papers that asked the same question but one had a completely different definition that was something like the definition for diffusion and one was the same as mine, so im confused how do i know when to use which definition? and is my definition right?

I also lost marks in my mock exam for writing down that definition so i really dont know :/

Hey,

OK,,that is not what i learnt about active transport...heres what i learnt:
Active transport is the net movement of gases against the concentration gradient using energy from respiration. EG: used to move nitrate ions from soil to the root and into stem, petal and leaves.

 

[Xenarra]

Hey,

Can someone write something about ecology because i don't think i studied enuf from it :/
Also something about the penicillin,fermentation and lactobacillus bulgaricus and streptococus thermophilus.
they seem hard.

BR,
Xenarra

Ecology isn't hard, it's just really long. First there's food chains and webs, you gotta know things like producers and primary/secondary consumers.
Then there're pyramids of biomass/energy, I never really focused on those, they don't come in exams alot.
There's also water/nitrogen/carbon cycles, if you understand those they're easy to write. And finally there're fertilizers, pesticides, weed-killers. Those might be the hardest, since they require you to memorize some advantages and disadvantages. I know I'm just mentioning headlines, but I'm gonna write some summarized points on each once I re-read them off my notes again xD
~And about lactobacillus and streptococcus, I don't think you have to memorize the names. You just have to know that they're bacteria added to milk, then they respire anaerobically on milk lactose to give lactic acid, that's acidic and reduces milk's pH, denaturing the milk proteins and causing it to coagulate and become thick. [Books mention that milk is heated to 90 C then cooled to kill bacteria before the whole procedure, and 'homogenized' to make the fat content the same in the whole milk. Boring points that books use to screw up interesting topics xD]
--Wow I'm really loving this thread, re-writing things I learnt makes me remember them more and I learn alot from reading what others write. Specially since I like reading things off the computer than checking some boring notes-books xD --

Hey,
thanks, guess i got it all intact...thot there was more to learn...lol...yea this is what my teacher said:
If you teach others, you are teaching yourself. It is a much better way of studying.
so i guess this forum is helping everyone alot!

BR,
Xenarra

 

[Divalicious]

[
OK,,that is not what i learnt about active transport...heres what i learnt:
Active transport is the net movement of gases against the concentration gradient using energy from respiration. EG: used to move nitrate ions from soil to the root and into stem, petal and leaves.

Try to say 'substances' instead of 'gasses' , since it's not always gases. For example, active uptake of glucose from the ileum through the villi.
You could also add 'from an area of low concentration to an area of high concentration'