Biology Predictions/Thoughts (4 Viewers)

[lily5885]

Only curveball will be the final 20 marker with 2 pages of stimulus.

8marker max hehe

 

[abstractaviator]

is anyone else struggling to study for this exam? every time I try reading my notes I start yawning and falling asleep

 

[Leadmen4y]

is anyone else struggling to study for this exam? every time I try reading my notes I start yawning and falling asleep

reading ur notes is probs the most ineffective study strategy out there, just do some papers lol

 

[mikrokosmos]

reading ur notes is probs the most ineffective study strategy out there, just do some papers lol

i agree! i've been handwriting summaries for the harder parts, and doing past hsc questions/past papers

 

[abstractaviator]

you guys are right tbh, are there any past papers which are the best or is it fine to do just do any?

 

[Leadmen4y]

you guys are right tbh, are there any past papers which are the best or is it fine to do just do any?

selective school trials usually can't go wrong, the 2 new syllabus hsc papers r probs the best practice u could get so make sure to do those too

 

[icycledough]

is anyone else struggling to study for this exam? every time I try reading my notes I start yawning and falling asleep

As mentioned above, you want to be doing forms of active study or recall, rather than passive study, which involves just plainly reading notes for the sake of it. Make it meaningful what you are trying to do; if not full practice exams, work on questions from modules you may not be as strong at, watch Youtube videos to consolidate specific knowledge if necessary, etc.

 

[lily5885]

can someone please tell me the difference between independent assortment and random segregation?

THANKS

 

[zizi2003_]

can someone please tell me the difference between independent assortment and random segregation?

THANKS

ind. assortment is the random alignment of the homologous chromosomes in metaphase I of meiosis. This means that the inheritance of alleles on each chromosome is independent of each other (maternal and paternal chromosomes could align in any manner along the metaphase plate)
whilst random segregation is basically when 2 alleles separate at random into gametes in anaphase I of meiosis. This means that there's 50% chance that either allele will end up in either gamete

 

[lily5885]

ind. assortment is the random alignment of the homologous chromosomes in metaphase I of meiosis. This means that the inheritance of alleles on each chromosome is independent of each other (maternal and paternal chromosomes could align in any manner along the metaphase plate)
whilst random segregation is basically when 2 alleles separate at random into gametes in anaphase I of meiosis. This means that there's 50% chance that either allele will end up in either gamete

thank YOU so much life saver, i had trouble understandingthis. But one thing,for random segregation,is it 2 alleles of the same gene ?

 

[zizi2003_]

thank YOU so much life saver, i had trouble understandingthis. But one thing,for random segregation,is it 2 alleles of the same gene ?

yess basically. coz remember homologous chromosomes have the same gene located on the same loci (position), but each gene may have diff alleles
but in the case of linked genes (when more than 1 gene is located on the same loci on a chromosome)- these are inherited together and dont experience random assortment/segregation
this diagram can help u understand also

 

[shadowlike04]

Random segregation is the random separation of homologous chromosomes in anaphase I of meiosis and the random separation of sister chromatids in anaphase II and this ensures that parental genes are separated randomly and equally into gametes during meiosis.

 

[zizi2003_]

Random segregation is the random separation of homologous chromosomes in anaphase I of meiosis and the random separation of sister chromatids in anaphase II and this ensures that parental genes are separated randomly and equally into gametes during meiosis.

doesnt random segregation only serve a purpose in anaphase I? since anaphase II does not result in any sort of variation- phase 2 is apparently the same as mitosis

 

[shadowlike04]

I think because the sister chromatids still need to separate randomly to ensure a fully random set of chromosomes in each gamete so it serves a purpose in Meiosis II. The second phase of Meiosis II is different to mitosis as it occurs in haploid cells with recombinant chromosomes.

 

[zizi2003_]

I think because the sister chromatids still need to separate randomly to ensure a fully random set of chromosomes in each gamete so it serves a purpose in Meiosis II. The second phase of Meiosis II is different to mitosis as it occurs in haploid cells with recombinant chromosomes.

yea ofc what i meant was that phase II is similar to mitosis in the sense that it also involves the separation of sister chromatids + there's no genetic variation introduced in the second phase whatsoever
so hence why random segregation only really serves a purpose in anaphase I

 

[theoneandonlyshrek]

guys wth do we actually have to know this I genuinely dont remember being taught this at all

 

[Leadmen4y]

yea ofc what i meant was that phase II is similar to mitosis in the sense that it also involves the separation of sister chromatids + there's no genetic variation introduced in the second phase whatsoever
so hence why random segregation only really serves a purpose in anaphase I

not 100 percent certain but i think u meant independent assortment which actually occurs in metaphase I, random segregation occurs in anaphase II
edit: mb didn't read what u wrote earlier

 

[Leadmen4y]

guys wth do we actually have to know this I genuinely dont remember being taught this at all

pretty sure its not specified but I think the syllabus says something along the lines of 'mechanisms of meiosis that introduce genetic variation' which is what is mentioned here (independent assortment + random segregation)

 

[zizi2003_]

random segregation occurs in anaphase I only as the second phase of meiosis does not result in any variation, merely the separation of sister chromatids
see https://ib.bioninja.com.au/higher-l...and-evolu/101-meiosis/mendel-and-meiosis.html for more info
i remember having a discussion about this with Hiva on some thread earlier

 

[shadowlike04]

But without random segregation of sister chromatids in anaphase 2 non disjunction will occur. If you get a question regarding the mechanisms of variation in meiosis, I don't think it will be incorrect to say that random segregation occurs in both the first and second division of meiosis.