It's over!

[kenhung123]

Really??? I thought the mutant allele was the one cut??

[Studyinghard]

Was the gel electrophoresis 2 bands 105 60kbp?

i had one band :S i thought it said that they had no history of the disease (the one we had to label the bands for ) what did people get?

I had two bands.

idk about this question but having one bad on that is dodgy becuz it was worth 2 marks so if u have 105 and 65 or whatever it was then that would be a good guess. never liked those questions.

i'm pretty sure you has to draw a 105bp strand and a 65bp strand, bc the normal allele was cut with the RE whereas the mutated allele wasnt, it showed this on the DNA sequence diagram above
hence bc the person had no history of the mutated allele, the RE would have cut the DNA at those 2 places to form a 65 and 105 bp strand

but it was homozygous for the genotype . how can u have two different strands :S?

[forsaken231]

the mutated allele was the one that wasn't cut. therefore two bands needed to be drawn, as the one that WAS cut was heterozygous and had it's unaffected cut

[steph_r]

Was the gel electrophoresis 2 bands 105 60kbp?

yehhh same here.

i had one band :S i thought it said that they had no history of the disease (the one we had to label the bands for ) what did people get?

i had one really thick band on the 100 line because i think it said the person was unaffected and im pretty sure the disease was a recessive one. so the band asked for unaffected homozygous so i put one thick band to show two 105 pairs..anyone else?

i put a single band at 165kb, as the restriction enzyme wouldnt cut the DNA, meaning the piece is intact and is 165kb

[LFTM]

this is depressing...

[simpak]

the mutated allele was the one that wasn't cut. therefore two bands needed to be drawn, as the one that WAS cut was heterozygous and had it's unaffected cut

This is what I thought.

[kenhung123]

the mutated allele was the one that wasn't cut. therefore two bands needed to be drawn, as the one that WAS cut was heterozygous and had it's unaffected cut

Are you sure the mutant allele wasn't the one what was cut?
Why is it that it is 2 marks for drawing 2 bands?

[Studyinghard]

at the end of the day. i think EVERYONE found this exam hard. i havent heard one person say it was a easy or like they finished with alot of time to spare so an A+ or an A isnt impossible even with all these mistakes

[forsaken231]

the mutated allele was the one that wasn't cut. therefore two bands needed to be drawn, as the one that WAS cut was heterozygous and had it's unaffected cut

Are you sure the mutant allele wasn't the one what was cut?
Why is it that it is 2 marks for drawing 2 bands?

Yeah because on the left was the homozygous affected, which had neither of it's strands cut. The one on the right, which was homozygous, MUST have had it's unaffected strand cut, otherwise both strands on the left would have been cut.

[kenhung123]

OK Anyone from MHS, Mac Rob, Mt Scopus? If so, how did your class go? If you say bad then obviously its hard for the majority.

[steph_r]

the mutated allele was the one that wasn't cut. therefore two bands needed to be drawn, as the one that WAS cut was heterozygous and had it's unaffected cut

Are you sure the mutant allele wasn't the one what was cut?
Why is it that it is 2 marks for drawing 2 bands?

In the question stem, it did have "band(s)" so it's not meant to be 2 bands for 2 marks.. who knowssss

[Studyinghard]

waht did people write about the reason for apoptosis in the first question. that was pretty lame. i was like ugh. some cells cannot go through mitosis to stop webbing and stuff.

[shinny]

no but its not the contraction of spindle fibres that creates the movement, its the contraction of the proteins in the centromere of the chromosome. just another quality ambiguous question from VCAA

Spindles fibres are proteins. They do contract to split contromeres.

its the proteins in the kinetochore of the centromere that create the movement

Heinemann biology 2 text book says in anaphase the spindles contract to split the contromere...that was the most appropriate answer anyway

What gwood21 said is correct. After reading up, the kinetochore does act like a 'winch' as others have said to move the chromosomes along the fibres. HOWEVER, kenhung123 is also correct. You're both right. Both these mechanisms operate, but the winch accounts for around 75% of the movement, and the shortening 25%. As I said before the shortening occurs via removal of protein 'monomers' from a chain, so it's not necessarily a contraction per se, but I don't think this level of knowledge would be expected. Then again, I wouldn't expect any of this knowledge to be expected so hell, I have no idea what to expect from VCAA. HENCE, I think it's B. I don't think polar bodies count as gametes.

[silva]

OK Anyone from MHS, Mac Rob, Mt Scopus? If so, how did your class go? If you say bad then obviously its hard for the majority.

im from SKevs and we have a very smart year group and everyone found it challenging

[kenhung123]

waht did people write about the reason for apoptosis in the first question. that was pretty lame. i was like ugh. some cells cannot go through mitosis to stop webbing and stuff.

Error in DNA duplication?