Biology P4 random notes

[zeebujha]

Captive breeding vs selective breeding:
-Selective breeding reduces genetic diversity
Captive breeding needs to maintain maximum diversity
-Selective breeding chooses parents on grounds of phenotype
Captive breeding parents should not be chosen for traits since weak organisms may house needed alleles
-Selective breeding for the benefit of humans
Captive breeding for the benefit of the species

 

[angel eyez]

does any one of u know which enzymes r present in kreb cycle? :Search:

 

[bionology]

1. Cytrate synthase
2. Malate dehydrogenase
3. Fumarase

However, you do not need them, (not in the syllabus)

 

[zeebujha]

GLYCOPROTEIN PEPTIDASE!!!!!!!!!!!!!!!!!!!!!!!!! OR TRANSPEPTIDASE!!!!!!!!!!!!!!
which is the enzyme involved in formation of crosslinks???
both have appeared in the MS

 

[YuriGagarin]

@zeebujha glycoprotein peptidases is written in cie endorsed book so i suggest u to go with it.

 

[lillyevans]

DNA sequencing

-sodium hydroxide solution breaks dna apart into single strands.
-restriction endonucleases are used to cut dna into sections (e.g EcoR1, BamH1, Hind III etc)
-Dna fragments are separated in an agarose gel using electrophoreses
-nitrocellulose sheet is placed on gel. single strand dna stick to it in the same specific pattern as present on gel. this process is called Southern blotting.
-nitrocellulose sheet is incubated with probe. The radioactive / florecent probe will base pair with the required gene
-portions of dna not bound are washed off
-the remainig dna still attached to nylon membrane is placed next to sheet of x ray film
-the radioactive probes of this dna expose to the film revealing a pattern of light and dark bands

 

[xenaprongs]

u r rite..thanks..i also saerchd frm google..it also said same!

 

[abuhantash]

Ok so before, it was said that when temp. increase >>> respiration rate increase >>>> stomatal closure increase . I still don't understand why! o.0 respiration uses osidises the glucose to GIVE water and carbondioxide!!!!!!!

If however, stomatal closure was due to increased rate of tranpirtation due to INCREASE IN TEMP .. that I understand

 

[abuhantash]

YOU GUYS DIDNT MENTION PHOTOPERIODISIM. It was added to our syllabus this year ( or so I was told, i dont check the syllabus) and any information about it would be great!

 

[beso2011]

it's not in da textbook and i didnt find it in the specification could u please post a link that shows that it's in your syllabus as Photoperiodism is a very hard and loooong story .

 

[beacon_of_light]

I checked the syllabus and photo periodism isn't part of the syllabus !

 

[unknown75]

is sympatric speciation in our syllabus

 

[beacon_of_light]

Yeah it is in our syllabus! And it is asked in terms of polyploidy.

 

[samy]

can somebody please explain the pregnancy test using the monoclonal antibodies.

 

[poisonedrose]

Sure.
So basically after a woman becomes pregnant, they produce a hormone called HGC(from the placenta) And here's how the preg. kit works.
1- sampler- the dipstick with absorbent pad
2- On the surface of the pad are monoclonal anitibodies specific to HCG and to which colored latex particles are attached. When the pad is moistened molecules of the antibody begin to move.
3- Sampler is dipped into urine- if HCG is present, it will bind to the monoclonal antibodies and will be drawn up the pad.
4- Further up the pad is an area at which there is a line of immobilized HCG antibodies
5. Any HCG molecules drawn up the pad(like, from step 3 basically) will bind with these antibodies and the latex particles will create a colored line.. which shows a + result
6. Further along the pad is a second line of immobilized antibodies to which will bind any HCG antibodies without HCG. A colored line will form in the second area, and not the firm, confirming that the result is -

Hope this helped !

 

[poisonedrose]

is sympatric speciation in our syllabus

This is what sympatric speciation is
This occurs when two overlapping species do not interbreed due to some other factor, usually a change in breeding season.
Most species are only fertile for a short time, so a small change in timing can easily lead to reproductive isolation. Alternatively, species may inhabit different areas within the same region.
Birds often nest at different heights and feed on different food, leading to the selection of different alleles for different beak sizes and shapes and, eventually, to new species. Even if mating does occur, the gametes of the two groups may not fuse, or the zygote may not develop, or be infertile. These factors would all prevent interbreeding, and so ensure that
reproductive isolation continues and so the new species remain distinct.

 

[zwitterion7]

MONOCLONAL ANTIBODIES

STEPS IN PRODUCTION
1. Injection of antigen in mouse.
2. Mouse killed after two weeks.
3. PLasma cells taken from spleen.
4. Plasma cells fused with myeloma cells (cancer cells).
5. Hybridoma cells cultured in ideal conditions.
6. Collection of monoclonal antibodies.

USES AND PURPOSE

1. diagnosis and treatment of certain diseases.
2. identification of tumours.
3. blood grouping for transfusion.
4. tissue typing for transplant.
5. identification of different bacteria.
6. identification of HIV.
7. pregnancy test.
8. Artificial passive immunity.
9. treatment of cancer as magic bullet.

 

[zwitterion7]

is sympatric speciation in our syllabus

This is what sympatric speciation is
This occurs when two overlapping species do not interbreed due to some other factor, usually a change in breeding season.
Most species are only fertile for a short time, so a small change in timing can easily lead to reproductive isolation. Alternatively, species may inhabit different areas within the same region.
Birds often nest at different heights and feed on different food, leading to the selection of different alleles for different beak sizes and shapes and, eventually, to new species. Even if mating does occur, the gametes of the two groups may not fuse, or the zygote may not develop, or be infertile. These factors would all prevent interbreeding, and so ensure that
reproductive isolation continues and so the new species remain distinct.

I dont think this is correct. Isnt sympatric speciation the one in which polyploidy occurs.

 

[zwitterion7]

Spread of antibiotic resistance among bacteria:
Most bacteria reproduce rapidly and thus there is frequent DNA replication. This increases chances for mistakes during DNA replication process (mostly gene mutation) and this is compounded by the lack of gene editing enzymes which can proofread. Some of these mutations can provide resistance to the antibiotics and these mutations can be passed onto a large number of descendants via vertical transmission. In some cases, the mutation for resistance gene can be on plasmid. This gets transferred via horizontal transmission even to different species. This could be by conjugation, transformation or transduction. The bacteria with the resistance gene will be favored by selection and their allele frequency will increase over many generations

why would the bacteria with resistance gene be flavored by selection??

 

[poisonedrose]

.

I dont think this is correct. Isnt sympatric speciation the one in which polyploidy occurs.

It is. Polyploidy is an /example/ of sympatric speciation. Polyploidy occurs due to abnormal cell division-the offspring and parent are 'reproductively' isolated. Hence why it's sympatric speciation