Biology Unit 4 Questions Megathread

[Reckoner]

Kaille, if the question asked for allele, then yes 1/2 would be correct

[malekv]

What is the difference between adaptive radiation and divergent evolution?

[jenerator]

An adaptive radiation is an evolutionary process drivin by natural selection. It is form of speciation in which  one species gives rise to multiple species that exploit different niches in the environment. It is rapid.

Divergent evolution on the other hand is when a group from a specific population develops into a new species in order to adapt to their environment. As a result they evolve into diff species

[jenerator]

hey guys, did you realise that the insides of a  sharks brain and a human vagina look quite alike? I wonder kind of evolution bought this to come about.......

[Russ]

Yeah it's a weird relationship but it's probably got to do with conserved structures because they're more stable within the body etc.
That, or it's a complete coincidence

[lexitu]

Maybe the female sharks got sick of males thinking with their you know what...

[WhoTookMyUsername]

1) In a cladogram / phylogenic tree does a line coming away from a strait line indicate The new line evolved from the straight line? Or is this an incorrect diagram?

2) Does a cline refer to phenotypic variation along an environmental gradiant DUE TO differences in environmental factors influentially the SAME genotype differently or the different selective pressures selecting for DIFFERENT genotypic combinantions ? ( i think its the latter... but definitions in dictionaries are loose).

[simpak]

1) In a cladogram / phylogenic tree does a line coming away from a strait line indicate The new line evolved from the straight line? Or is this an incorrect diagram?

My spatial skills are terrible, can you perhaps give an image?

[jenerator]

lololooll @ lexitu

[Drunk]

2) Does a cline refer to phenotypic variation along an environmental gradiant DUE TO differences in environmental factors influentially the SAME genotype differently or the different selective pressures selecting for DIFFERENT genotypic combinantions ? ( i think its the latter... but definitions in dictionaries are loose).

Fairly sure it's the latter also.

Quoted from Biolnotes: "When seeds are collected from plants growing at different altitudes and are then grown in the laboratory, where conditions are constant for all samples, the plants grow to about the same heights as the plants in the source environment. This shows that the variation is genetic. Different selection pressures have led to different allele frequencies in the populations in different environments."

[Zebra]

HI guys!

1)DEFINE:dna polymerase,rna polymerase (is it good enough to just say that the two catalyse the process of replication/transcription?)
2)Primers are short strands of Dna that bind to the promotor region of the flanking region to initate transcription right!?!?
3)What is an okazaki fragment?lagging strand? ( I CAN IDENTIFY THESE IF GIVEN A DIAGRAM BUT HOW CAN DEFINE THE TWO?)
why wouldn't a cloned organism have the same genetic composition as the parent who donored their nucleus?
4)Down's syndrome = 3n? or simply 3 chromosomes in the 21st set?
5)Are all plasmids circular? (is it good enough to just say its an extrachromosomal bit of dna in a bacterial cell?)
6)What's the purpose of having plasmids?
7)How can plasmids replicate independently from the bac. cell?
8)How is binary fission different to mitosis? (can someone plz go over the steps involved)?
9)Addition of antibiotic resistant gene into a plasmid allows us to identify which bacterial cells took the plasmid?
(BUT WOULDN'T OTHER BAC CELLS ALREADY HAVE ANTIBIOTIC RESISTANT ALREADY DUE TO MUTATION?)
10)Difference between DNA fingerprinting, DNA profiling (is gel electrolysis the latter one?)
11)Difference between a rna primase and rna polymerase
12)Biogeography= the whole purpose of studying(geographical distribution of an organism this is to support evolution right?
13)WHAT IS ADAPTIVE RADIATION?(evolution due to natural selection right? then, what's a term used to describe evolution due to humans?(artificial selction))
14)I don't understand how females start with their eggs from birth? (doesn't this take away the entire purpose of meiosis?)
15)How is female meiosis different to male meiosis?
16)As far as I know, mitochondria in our cells have non-coding parts that mutate at a fast rate, if this is true, how can we use
mtDNA to find more about our maternal lineage? (I ASK THIS BECAUSE I'M ASSUMING THAT THE CODING SECTIONS OF mtDNA in all of us are very very similar)
17)Can someone define what an independent assortment is? (two chromosomes in a homologous pair not affecting each other's behaviour during separation?hmm..)
18)Frameshift mutation=Blocked mutation?
19)DEFINE:Ligase? (is there ligase for RNA molecules too?)
20)How come polyploid plants can reproduce but not polyploid animals? (OR do I have a wrong understanding of polyploidy..?)
21)Why can't aneuploid individuals reproduce? (e.g two people with down's syndrome ? WHY?)
22)Purpose of test cross? Diff b/w test cross and back cross which determines allele status of offspring as well as being useful for breeding purposes?
23)Diff between incomplete/partial varation and codominance? ( Can we go through this again...)
24)If the pre-mRNA is spliced in many ways to produce different proteins, would all the possible proteins be different combinations of its exons or would it include any introns?
25)

defs of
Alternative Splicing

Gene Regulation

Reverse Transcriptase

Non-disjuction

Polyploidy


THANK YOU!!

[Russ]

This might take a while, I'll probably have to come back to it later.

1. I would say how they do it (ie join nucleotides etc.)
2. RNA not DNA and they don't bind promoter sequences, they're synthesized
3. Okazaki are just fragments of ssDNA that form on the lagging strand as it is unwound by helicase, you don't really need more than that. The lagging strand is the one being synthesized in the 3' direction. I seriously doubt you'll be asked for definitions though.
3a. SCNT just gets the same genetic starter kit, there are plenty of other things that affect the genome (intra uterine environment, random mutation, etc.)
4. Trisomy 21 = 3 copies of 21 NOT the whole genome
5. Not at all times, but generally yes.
6. They replicate independently and are very easy to transfer between organisms, so they can confer new traits with relative ease. Worth pointing out that they're not produced by the bacteria, they're just parasites that hitch a ride.
7. You don't need to know the details
8. Produces only 2, genetically identical cells (clones). Can't remember the subtle other differences
9. Yes, just add the antibiotic to the dish you're plating on. Why would they already be antibiotic resistant, it's not like every bacterium is resistant to every antibiotic. Anyway, when you're working with bacteria and inserting a resistance plasmid to select certain ones, you will be using bacteria that specifically aren't resistant prior to plasmid transfection.

[WhoTookMyUsername]

1) In a cladogram / phylogenic tree does a line coming away from a strait line indicate The new line evolved from the straight line? Or is this an incorrect diagram?

My spatial skills are terrible, can you perhaps give an image?

don't worry about it. i'mpretty sure the diagram is wrong.


4) just confirming that homo neanderthal is a gracile..

5) is a species a group of individuals ale to produce viable, fertile offspring I nature? e.g. Two populations separated by a river may not be able to interbreed in nature, but may be same species...

Is a better definition..l in nature when interbreeding not inhibited by geographical?

[Reckoner]

Hi, could someone please explain what an operon is, the different parts that are present and how they function?
Thanks in advance

[simpak]

5) is a species a group of individuals ale to produce viable, fertile offspring I nature? e.g. Two populations separated by a river may not be able to interbreed in nature, but may be same species...

Is a better definition..l in nature when interbreeding not inhibited by geographical?

I was always under the impression that it just meant 'naturally' as in - if you put those two animals together and they happened to mate, then they could do so to produce viable offspring without forced human intervention or technological application.

If you think about it, I might have a dog (like my own schnauzer!) in Australia, but there are also dogs in America.  They can't breed in nature, but I still consider them the same species because if I took my dog to America then their breeding would be possible...if my dog wasn't desexed.  But a hypothetical situation!