OCR Biology F215 Control, Genomes and Environment Fri 15 June 2012

so is it acceptable or not ?

Guys, ask me questions!

hey how are you
what is the process of spitting eggs(3)
ask me as well

HELLO! Just got home! Knackered. How's you?

Meiosis ... Telophase?

And hmm...

Explain PCR. Or are you still doing chapters?

doing that tomorrow but did everything before PCR ! i will finish the whole book by friday next week which will leave me 1 week finishing past papers

no splitting is talking about the cow e.t.c ? not meiosis

No... I don't know what you're on about :/ Heh. Wow. And cool. Congratz. Sounds like a super organized plan.

yes i will be sooo happy finishing it lool
no splitting embryo ? its on where you collect sperms from the male cow and ovum from female and in vitro fertilisation happens?

Oh!! Right! In Vitro fertilization. I doubt we'll be asked about that but thanks for reminding me..

Hmm.

Your turn!

Guys, ask me questions!

now you ask me my turn

Would you like questions on everything in unit 5? Or specific chapters?

Explain the sequence of events in apoptosis

This was posted from The Student Room's Android App on my HTC Desire HD A9191

EVERYTHING and anything. ) Please?

There I gave ya one in my last comment

Explain the sequence of events in apoptosis.

Oh btw are you doing f214?

This was posted from The Student Room's Android App on my HTC Desire HD A9191

I HAVE A SUGGESTION:

I THINK INSTEAD OF ASKING EACH OTHER THE STANDARD QUESTIONS THAT INVOLVE REGURGITATING FROM PAST PAPERS OR THE TEXT BOOK, I FEEL WE SHOULD ASK EACH OTHER SYNOPTIC QUESTIONS THAT HAVEN'T YET CAME UP YET AS THIS CAN OFTEN BE OVERLOOKED, AFTER ALL IT IS 20% OF F215 (P.S. SORRY FOR WRITING IN CAPITALS)

ok, ill start off with a relatively easy one just to get things started, what happens when a plant wilts (3 marks)

Can anyone explain the species concept stuff to me? I've read the spread on pages 142-143 loads of times but it's just not going in. None of it makes any sense to me.

Good idea . Too much water leaves the plant cells by osmosis down a water potential gradient. The plant looses it turgor pressure.

F215 spec point, "State that cyclic AMP activates proteins by altering their three-dimensional structure". So question, cAMP is a second messenger so what does a second messenger do? And explain cAMP's role as a second messenger in the action of adrenaline.

Another two questions. The hormone adreno-corticotropic hormone (ACTH) released from the pituatary gland stimulates the release of corticosteroid hormones. Where specifically in the adrenal glands are the corticosteroid hormones like mineralocorticoids and glucocorticoids released from and what is their function of mineralocorticoids and glucocorticoids.

yeh you're on the right track, talk about if the rate of transpiration exceeds the rate of water loss then the plant wilts. it does this by releasing absiscic acid which is a stress hormone that closes stomata and therefore reduces transpiration and the plant wilts

a secondary messenger is on the inside of the plasma membrane and in the case of cAMP, when the hormone binds to the plasma membrane receptor ATP is converted to cAMP by adenyl cyclase. cAMP can then trigger a series of enzymic reactions within the cell. this happens because the primary messenger (eg adrenaline) cant pass into the cell because its an amino acid derivative.

i think corticosteroid hormones are produced by the adrenal cortex, i cant quite remember their function though haha

You need to know the two different concepts on how to define species. First is the biological species concept which states ," species are a group of similar organisms that can interbreed and produce fertile offspring and are reproductively isolated from other such groups" . The phylogenetic species concept states, "species are any group of organisms that have the same embryology, physiology, behaviour and morphology. They share the same ecological niche". Learn the two definitions.

Problem with the biological species concept is that it excludes the organisms that dont reproduce sexually or the organisms that dont look alike. Back to the phylogentic species concept, any group of organims with haplotypes (haplotypes are a combination of alleles that are inherited together) that are similar are called a clade. It assumes that the group all come from one descendant, the word for that is monophyletic.

The difference between the cladistic approach and the taxonomic classification (Kingdom, phylum..etc) is that there is no distinction between living and dead species, all are included in the cladograms (a cladogram is a diagram that shows the relationship between the organsims, like you start with aancester and it shows you the descendants of that ancester). Cladistic approach looks at the DNA of the species and also looks at the evolotionary relationship between the species rather than just similarities. Hope that helped and please do correct me if I made a mistake

You need to know that the H zone gets shorter, as do the I bands. the Z lines pull towards each other. Then you just need to know the role of ATP (the ratchet mechanism) and role of calcium ions (to attach to troponin which moves trypomyosin). That's obviously shortened but they're the main things I think

^
I thought that was the biological sense of the word species? I get really confused with this two and my textbooks and my teachers are just awful at explaining the difference. I was always under the impression that the biological concept of a species is 'Organisms that have similar anatomy and physiology and can also interbreed to produce fertile offspring.' and that the phylogenetic concept was that organisms that share common recent ancestors were species :/

One of my textbooks also says that the cladistics method is different from the Linnaen method because it focuses on evolutionary history rather than similarities....but I thought the Linnaen system looked at evolutionary history and then classified organisms into genus, order, etc by how closely related they were? :/