Psyxwar's Biology 3/4 Question Thread

[alondouek]

Is saying the "dominant allele" incorrect terminology? Would I have to say "the allele coding for the dominant trait"?

Yes. It is erroneous to say "dominant/recessive allele", your alternative is correct.

Source: Got shouted at by teacher for doing this early in year 12

[vox nihili]

Yes. It is erroneous to say "dominant/recessive allele", your alternative is correct.

Source: Got shouted at by teacher for doing this early in year 12

The maths lecturer says it all the time too -.-

[psyxwar]

Yes. It is erroneous to say "dominant/recessive allele", your alternative is correct.

Source: Got shouted at by teacher for doing this early in year 12

ah damn, that takes ages to write out

[psyxwar]

Could someone define hominin, hominid, etc?

[Yacoubb]

Could someone define hominin, hominid, etc?

Hominin is the zoological tribe of organisms belonging to the genus Australopithecus or Homo.

[vox nihili]

Could someone define hominin, hominid, etc?

Hominid includes the great apes and the Pongids as well.

Hominins belong to the family Hominini

[psyxwar]

And hominoids belong to the superfamily hominoidea?

ATARnotes Heredity test, q5a:

Asks at which part of mitosis do spindle fibres attach to centromeres:

answer given is metaphase, but isnt it prophase?

[swagsxcboi]

And hominoids belong to the superfamily hominoidea?

ATARnotes Heredity test, q5a:

Asks at which part of mitosis do spindle fibres attach to centromeres:

answer given is metaphase, but isnt it prophase?

From what I remember, prophase is when the centrosomes move to the opposite ends and when the spindle fibres form
metaphase is when the chromosomes line up, and the spindle fibres attach to the kinetochores

[Yacoubb]

And hominoids belong to the superfamily hominoidea?

ATARnotes Heredity test, q5a:

Asks at which part of mitosis do spindle fibres attach to centromeres:

answer given is metaphase, but isnt it prophase?

Metaphase is when the spindle fibres attach to thw kinetochores located at the centromeres of the chromosomes. Prophase is just the beginning of the spindle fibres forming as the nuclear membrane is degraded and the chromatin continues to coil tightly (supercoil) around histone proteins, forming shortened and more condensed chromosomes made up of two chromatids joined at the centromere.

[psyxwar]

I think maphase is simply when chromosomes line up on the cell equator though. The actual attaching to kinetochores occurs during pro metaphase but... we don't cover this in VCE Bio... Textbooks say different things

[vox nihili]

I think maphase is simply when chromosomes line up on the cell equator though. The actual attaching to kinetochores occurs during pro metaphase but... we don't cover this in VCE Bio... Textbooks say different things

I agree on this. Prometaphase seems reasonable, but it isn't in the VCE course.

[Yacoubb]

I think maphase is simply when chromosomes line up on the cell equator though. The actual attaching to kinetochores occurs during pro metaphase but... we don't cover this in VCE Bio... Textbooks say different things

Yeah I think so many things have been dumbed down for the purpose of VCE Bio lol!

Hey quick question, what is pure breeding? My teacher took one mark off my SAC because she told me pure breeding was between organisms with the same genotype... I wrote that pure breeding is a cross between a homozygous dominant organism and homozygous recessive organism for a particular trait.

[psyxwar]

Yeah you're wrong.

It's either two homozygote recessives being crossed or two homozygote recessives being crossed, so all offspring have the same genotype (as their parents).

[Yacoubb]

Yeah you're wrong.

It's either two homozygote recessives being crossed or two homozygote recessives dominant being crossed, so all offspring have the same genotype (as their parents).

See, that's the thing. I've received so much conflicting info. Plus, one part of our SAC looked at incomplete dominance, and the cross was between RR and rr. The question asked how the experiment was an example of pure breeding. Well, RR and rr crossed gives all heterozygote offspring Rr, for which in our case, were light green peas.

I'm just puzzled because I'm confused as to whether its RRxRR and rrxrr, or RRxrr

[psyxwar]

See, that's the thing. I've received so much conflicting info. Plus, one part of our SAC looked at incomplete dominance, and the cross was between RR and rr. The question asked how the experiment was an example of pure breeding. Well, RR and rr crossed gives all heterozygote offspring Rr, for which in our case, were light green peas.

I'm just puzzled because I'm confused as to whether its RRxRR and rrxrr, or RRxrr

I dunno, doubt they'll ask a question on it + when they same "true breeding organism" in a question they always mean homozygous for that allele.