Biology Predictions/Thoughts (1 Viewer)

[Leadmen4y]

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

wait but isn't independent assortment how gametes are unrelatedly sorted to either side of the cell in metaphase I? (becoz I thought after that the chromatids r just pulled to the allocated side rather than randomly segretated) i thought random segregation was how each allele coding for the same trait are segregated which supposedly happens in anaphase II

 

[stressedadfff]

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

same

 

[theoneandonlyshrek]

same

im actually done for this exam im manifesting that nesa made it easy

 

[zizi2003_]

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.

nondisjunction has nothing to do with randoms segregation tho?? it's basically when a mutation occurs in the gene coding for the microtubules that form spindles, hence the chromatids fail to separate properly. The failure to separate properly has nothing to do with random segregation which is when alleles are randomly distributed into gametes
but ur overall point is right, mutations can absolutely be induced in phase 2 of meiosis and cause variation
but with that logic, mutations also arise during anaphase of mitosis and are hence a source of variation
i wasnt talking about variation in general (including mutations), i was talking about only random segregation as a means of variation that doesnt occur in anaphase II since it's just the separation of sister chromatids just like in mitosis

 

[zizi2003_]

wait but isn't independent assortment how gametes are unrelatedly sorted to either side of the cell in metaphase I? (becoz I thought after that the chromatids r just pulled to the allocated side rather than randomly segretated) i thought random segregation was how each allele coding for the same trait are segregated which supposedly happens in anaphase II

wdym by "gametes" are unrelatedly sorted to either side of the cell? yea independent assortment is when homologous chromosomes(maternal and paternal pairs) align in random pairs during metaphase along the metaphase plate
and yes ur definition of random segregation is right except it happens in anaphase I im sure,

 

[shadowlike04]

Mechanically, the process of meiosis 2 is similar to mitosis, though its genetic results are fundamentally different. The end result is production of four haploid cells rather than diploid cells.

Chromosome segregation occurs at two separate stages during meiosis called anaphase I and anaphase II - https://en.wikipedia.org/wiki/Chromosome_segregation

Mentioning non-disjunction when talking about random segregation is an error on my part I was trying to illustrate why segregation of chromosomes is essential.

 

[Leadmen4y]

wdym by "gametes" are unrelatedly sorted to either side of the cell? yea independent assortment is when homologous chromosomes(maternal and paternal pairs) align in random pairs during metaphase along the metaphase plate
and yes ur definition of random segregation is right except it happens in anaphase I im sure,

yeah my bad I meant homologous chromosomes. thanks for the explanation

 

[zizi2003_]

Mechanically, the process of meiosis 2 is similar to mitosis, though its genetic results are fundamentally different. The end result is production of four haploid cells rather than diploid cells.
Mentioning non-disjunction when talking about random segregation is an error on my part I was trying to illustrate why segregation of chromosomes is essential.

yea I wasnt trying to say that meiosis 2 is exactly like mitosis, i was just talking about the mechanics of it- how they both involve the separation of sis chromatids
mhmm but it sure is complicated as to whether random segregation occurs in anaphase 1, 2 or both, since a variety of sources say diff things
but yea I think they would accept it if we say both phases 1 and 2 at this point

 

[abstractaviator]

im actually done for this exam im manifesting that nesa made it easy

yea same this thread is making me realise how screwed I am

 

[Leadmen4y]

yea I wasnt trying to say that meiosis 2 is exactly like mitosis, i was just talking about the mechanics of it- how they both involve the separation of sis chromatids
mhmm but it sure is complicated as to whether random segregation occurs in anaphase 1, 2 or both, since a variety of sources say diff things
but yea I think they would accept it if we say both phases 1 and 2 at this point

yeah I saw it as anaphase II way back when we were doing mod 5 but I dug the theory n the textbooks all say its anaphase I or doesn't mention it like pearson. i think its confusing since apparently law of segregation and random segregation r different, and chromosome segregation occurs in both anaphase I and II but only I is random. hoping they don't ask meiosis on Monday at this point lol

 

[cloud_berry]

idk if i redo past trial papers or not, i already did all the practice papers for the new syllabus while studying for trials

 

[lily5885]

guys are you going to memorise examples of a genetic disease for each type of mutation like frameshift, chromosomal, etc

 

[icycledough]

idk if i redo past trial papers or not, i already did all the practice papers for the new syllabus while studying for trials

As biology is in 2 days, it really depends on you whether you want to do past papers, as there are definitely positives and some negatives. Past papers for the sake of it won't be effective, but timed past papers (closed book), marked after and gone through will be much more useful for your study. If you don't want to, then make sure you are doing some sort of active recall study, rather than just 'reading through notes or a textbook', which will prevent you from retaining information. You may want to consolidate your knowledge of weak topics through textbook questions, Youtube/Khan Academy videos, and other resources you have available.

 

[lily5885]

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

i somewhat agree. Reading yournotes is good for a general basis which is what ive been doing but then ive also balanced this with lots and lots of practice papers... not point indoing past papers if you have no idea what youre talking about

 

[lily5885]

past hsc questions in order of topics:

Module 5 Heredity - Reproduction

Year	Questions
2020	2, 3, 25(a-c)
2019	9, 27(a-b)
2019 Sample	1, 11(a-b), 12
2011	10

Module 5 Heredity - Cell Replication

Year	Questions
2020	16
2019	4
2019 Sample	2, 13(a-c), 14(a-b)
2018	4, 29, 33(a)(i)
2017	13, 17, 19
2016	10, 13, 26
2015	23
2012	29
2011	4

Module 5 Heredity - DNA and Polypeptide Synthesis

Year	Questions
2020	5, 20
2019	14, 33(a)
2019 Sample	3, 4, 15
2018	26(a), 28
2017	33(c), 34(a)
2015	11, 14, 34(b)
2014	32(a), 33(a)
2013	32(a), 33(b)
2012	8, 17, 33(b)
2011	33(b), 34(a)

Module 5 Heredity - Genetic Variation

Year	Questions
2020	14, 19, 26(a), 26(b)
2019	11, 17, 28(a), 30, 33(b)(i)
2019 Sample	8, 5, 6, 7, 9, 16(a-b), 17
2018	14, 19, 28, 33(c)(ii)
2017	12, 15, 24(a-b), 28
2016	8, 14
2015	2, 15
2014	10, 15
2013	5, 18, 33(a)
2012	23(b)
2011	5, 17

Module 5 Heredity - Inheritance Patterns In a Population

Year	Questions
2019 Sample	10, 18(a-b)
2017	34(b), (e)
2014	33(c)
2013	33(e)
2011	34(d), (e)

Module 6 Genetic Change - Mutation

Year	Questions
2020	17, 18, 23(a-b), 28(b), 29
2019	3, 13, 15, 22, 25(a-b), 26
2019 Sample	1, 2, 3, 4, 8(a-c), 9
2018	26(b)(i), 33(b)
2017	34(c)
2016	4
2014	1
2012	25, 33(d)

Module 6 Genetic Change - Biotechnology

Year	Questions
2019 Sample	5, 6, 10, 11(a), 12(a)
2018	32(a)(i), 33(d), 33(e)
2016	18
2015	29, 33(a)(i), 33(d)(i)

Module 6 Genetic Change - Genetic Technologies

Year	Questions
2020	12, 13
2019	8
2019 Sample	7, 10, 11(a-b), 12(b), 13, 14
2018	10
2017	31, 33(b)
2016	33(c)(ii), 33(e)
2014	16, 33(b)
2013	30, 33(d)
2012	1, 33(a)
2011	33(d)

Module 7 Infectious Disease - Causes of Infectious Disease

Year	Questions
2020	4, 7, 32(a), 32(b)(i)
2019	31(a-b)
2019 Sample	1, 2, 3, 12, 13
2018	8, 11, 22, 30
2017	14
2016	2, 15, 25
2015	9
2014	5, 12, 13
2013	1, 24, 28(a)
2012	4, 16
2011	9, 19, 29

Module 7 Infectious Disease - Responses to Pathogens

Year	Questions
2019 Sample	4, 5, 15(a-b)

Module 7 Infectious Disease - Immunity

Year	Questions
2019	5
2019 Sample	6, 7, 8, 16(a-b), 17(a-b)
2018	3, 16
2017	4, 6, 11, 30
2016	11, 19, 20
2015	17, 19, 20, 27(b)
2014	17, 21
2013	2, 4, 6, 21
2012	3, 13
2011	8, 14, 16

Module 7 Infectious Disease - Prevention, Treatment and Control

Year	Questions
2020	6, 15, 21, 22
2019	2, 10, 32(a-b)
2019 Sample	9, 10, 12
2018	24, 30
2017	29
2016	28, 30
2015	12, 13, 21
2014	11, 18, 22(a), 23, 25
2013	3, 7, 11, 28(b)
2012	6, 7, 27
2011	7, 24, 26

Module 8 Non-Infectious Disease - Homeostasis

Year	Questions
2020	1, 31(a-b)
2019	12, 21, 29
2019 Sample	1, 2, 3, 10(a-b)
2018	9, 21, 26(b)(ii)
2017	1, 2
2016	23(b)
2015	3, 7, 8
2014	3
2013	14, 15, 17, 23
2012	18
2011	3, 32(a)

Module 8 Non-Infectious Disease - Causes and Effects

Year	Questions
2019 Sample	4
2014	22(b)
2012	5, 12

Module 8 Non-Infectious Disease - Epidemiology

Year	Questions
2020	8, 9, 27(a)
2019	33(b)(ii), 33(c)
2019 Sample	5, 6, 11
2015	16
2012	23(a), 26
2011	27

Module 8 Non-Infectious Disease - Prevention

Year	Questions
2019	23
2019 Sample	7

Module 8 Non-Infectious Disease - Technologies and Disorders

Year	Questions
2020	11, 24(a-c)
2019	6
2019 Sample	8, 9, 13(a-b)
2018	7, 15, 26(b)(ii), 31(a)(c)(d)
2017	7, 32(a)(b)(c)(e)
2016	7, 9, 32(e)
2015	31, 32(e)
2014	6, 31(c)
2013	29, 31(b-d)(e)(ii)
2012	31(a-b)
2011	32(c)(e)

 

[lily5885]

Questions Covering Multiple Topics

Year	Questions	Topics
2020	28(a)	Mod 5 Cell Replication Mod 5 Genetic Variation
2020	32(b)(ii)	Mod 5 DNA and Polypeptide Synthesis Mod 7 Causes of Infectious Disease
2020	30	Mod 6 Biotechnology Mod 6 Genetic Technologies Mod 7 Prevention, Treatment and Control Mod 8 Prevention
2020	10	Mod 6 Mutation Mod 6 Genetic Technologies
2020	32(b)(ii)	Mod 5 DNA and Polypeptide Synthesis Mod 7 Causes of Infectious Disease
2020	30	Mod 6 Biotechnology Mod 6 Genetic Technologies Mod 7 Prevention, Treatment and Control Mod 8 Prevention
2020	32(c)	Mod 7 Response to Pathogens Mod 7 Immunity Mod 7 Prevention, Treatment and Control
2020	27(b)	Mod 8 Causes and Effects, Mod 8 Epidemiology
2019 Sample Mod 7	11, 18	Mod 7 Causes of Infectious Disease Mod 7 Prevention, Treatment and Control
2019 Sample Mod 7	14	Mod 7 Causes of Infectious Disease Mod 7 Responses to Pathogens
2019	28(b)	Mod 5 Cell Replication Mod 5 Genetic Variation
2019	18	Mod 5 Reproduction Mod 8 Homeostasis
2019	19, 20, 24	Mod 6 Biotechnology Mod 6 Genetic Technologies
2019	7	Mod 7 Causes of Infectious Disease Mod 7 Prevention, Treatment and Control
2019	1	Mod 7 Causes of Infectious Disease, Mod 8 Cause and Effects
2019	33(d)	Mod 7 Causes of Infectious Disease, Mod 8 Causes and Effects, Mod 8 Epidemiology
2019	16	Mod 7 Immunity Mod 7 Prevention, Treatment and Control
2014	29	Mod 5 Reproduction, Mod 5 cell replication
2012	30	Mod 7 Causes of Infectious Disease, Mod 7 Causes of Infectious Disease
2012	15	Mod 8 Homeostasis, Mod 8 Technologies and Disorders
2011	31	Mod 6 Biotechnology, Mod 7 Prevention, Treatment and control, Mod 5 DNA and Polypeptide Synthesis
2011	25	Mod 8 Homeostasis, Mod 8 Technologies and Disorders

 

[Leadmen4y]

i somewhat agree. Reading yournotes is good for a general basis which is what ive been doing but then ive also balanced this with lots and lots of practice papers... not point indoing past papers if you have no idea what youre talking about

yeah ofc its good to get a general understanding, but doing it more than even once is ineffective imo there are way better ways to memorise stuff like flashcards

 

[Leadmen4y]

past hsc questions in order of topics:

thanks for this, this is helpful

 

[theoneandonlyshrek]

guys are you going to memorise examples of a genetic disease for each type of mutation like frameshift, chromosomal, etc

yes!!!

 

[lily5885]

nondisjunction has nothing to do with randoms segregation tho?? it's basically when a mutation occurs in the gene coding for the microtubules that form spindles, hence the chromatids fail to separate properly. The failure to separate properly has nothing to do with random segregation which is when alleles are randomly distributed into gametes
but ur overall point is right, mutations can absolutely be induced in phase 2 of meiosis and cause variation
but with that logic, mutations also arise during anaphase of mitosis and are hence a source of variation
i wasnt talking about variation in general (including mutations), i was talking about only random segregation as a means of variation that doesnt occur in anaphase II since it's just the separation of sister chromatids just like in mitosis
View attachment 33922

thanksso much forthis,really helpedme !