quick question

[cipherpol]

Can someone give me a good definition of hominin and hominid? Everywhere I look gives me conflicting answers...

[minilunchbox]

Can someone give me a good definition of hominin and hominid? Everywhere I look gives me conflicting answers...

from what i know

a hominin is a group of primates the include apes, some monkeys and and humans.

hominids are bipedal and include homo sapiens and their descendants.

however i'm not too sure

It's the other way around according to VCAA.

http://www.vcaa.vic.edu.au/vce/studies/biology/biologyfaqs.html

[cipherpol]

From Nature of Biology:

"Modern humans (Homo sapiens) are the only hominins living on planet Earth today..."

I'm confused.

edit: thanks for the link, minilunchbox!

[scar]

I think VCAA is a bi confused by the Hominin / hominid issue too

Last years U4 Exam

Question 12
Two hominin (also called hominid) skull fragments were found in separate locations and each was associated
with a number of artefacts. Skull X was dated and shown to be 100 000 years old, while skull Y was dated at
20 000 years old.
The artefacts most likely discovered with skull Y but not skull X would be
A. fi replace fragments.
B. stone tools for cutting.
C. pigment used in rock paintings.
D. bones from hunted animals.

[kenhung123]

The term hominin is quite 'new'. They used to refer hominins in the group of hominids. Hominids are like apes, gorilla, orangutan, chimpanzees. Hominins are species homo (I am unsure on this one)

[qshyrn]

The term hominin is quite 'new'. They used to refer hominins in the group of hominids. Hominids are like apes, gorilla, orangutan, chimpanzees. Hominins are species homo (I am unsure on this one)

homonins are not only homo , they include australopithecus and all other species on the human line

[kenhung123]

I still don't understand why the question B is wrong. I understand your explanation that half+half=whole but that doesn't mean the haploid number isn't 7 right? Haploid definition is specifically 1 set of chromosomes. Polyploid means multiple sets and if you divide chromosome number of the number of set you get 1 set=haploid number? Maybe if they said the number of chromosomes in the gametes is 7 then its wrong. Please clarify?

Also I have done a little bit of research and apparantly helicase does take part in transcription?

[shinny]

Also I have done a little bit of research and apparantly helicase does take part in transcription?

Hmm, just done a little more myself.

RNA polymerase II refers specifically to the RNA polymerase which prokaryotes use to perform transcription with. This definitely has helicase-like properties, and hence, prokaryotes do not need helicase.

However, eukaryote RNA polymerase II is far less studied (I've only learnt about the prokaryote one at uni, not this), but this eukaryotic version of the enzyme does not have the helicase-like properties, and from what I can gather from wiki, helicase is involved in eukaryote (and hence human) transcription.

EDIT: DEFINITELY not at a VCE level. Wasn't even at a first year Med level =S We don't even use any of these numbering systems (RNA polymerase II is just known as RNA polymerase, and we're unaware of any others) so don't freak out guys. This is all more for self interest.

EDIT 2: Fixed incorrect info.

[kenhung123]

Could you please also answer the above question also?

[qshyrn]

I still don't understand why the question B is wrong. I understand your explanation that half+half=whole but that doesn't mean the haploid number isn't 7 right? Haploid definition is specifically 1 set of chromosomes. Polyploid means multiple sets and if you divide chromosome number of the number of set you get 1 set=haploid number? Maybe if they said the number of chromosomes in the gametes is 7 then its wrong. Please clarify?

Also I have done a little bit of research and apparantly helicase does take part in transcription?

this definition is also sorta confusing me  ive always thought haploid is half the diploid no. , not necessarily one set of chromosomes

[kenhung123]

Look up the definition. I think its usually thought of as half the number of chromosomes because we usually refer to humans and a majority of organisms which are diploid. Diploid organism forms gametes that have 1 set of chromosomes which is half the original 2 sets of chromosomes. So its kinda a coincidence that haploid is half the number of chromosomes

[shinny]

I still don't understand why the question B is wrong. I understand your explanation that half+half=whole but that doesn't mean the haploid number isn't 7 right? Haploid definition is specifically 1 set of chromosomes. Polyploid means multiple sets and if you divide chromosome number of the number of set you get 1 set=haploid number? Maybe if they said the number of chromosomes in the gametes is 7 then its wrong. Please clarify?

You need to distinguish between the concept of haploidy and monoploidy; a term not taught in VCE nor what I've come through yet (once again, this is all from wiki reading). To put it simply, the haploid number is always defined as the number of chromosomes in the gamete of an individual (just remember, haploid always equals half, which is where the term is derived from I guess), whereas the monoploid number is the number of unique chromosomes in a single complete set. In humans, because we aren't polyploids, the haploid and monoploid number are the same since our gametes only have 1 set, and our somatic cells only have 1 set which is doubled up. However, the question uses wheat which has 6 sets of chromosomes. Wheat gametes have 3 sets of chromosomes (3N) in their gametes, but only one set is unique. Thus, it'd be 21 for the haploid number, and 7 for the monoploid.

Refer to http://en.wikipedia.org/wiki/Ploidy if you need more info (although this is basically just a longer explanation of what's there).

[TrueLight]

shinny you got it mixed up

what you are referring to... the a, beta, delta is DNA polymerase invovled in replication

rna polymerase 2 is still used in eukaryortic transcription, its just more complicated in the fact that it needs a lot more regulatory proteins and transcription factors, silencers, enhancers...etc ...  

[shinny]

shinny you got it mixed up

what you are referring to... the a, beta, delta is DNA polymerase invovled in replication

rna polymerase 2 is still used in eukaryortic transcription, its just more complicated in the fact that it needs a lot more regulatory proteins and transcription factors, silencers, enhancers...etc ... 

Ah whoops sorry. Was doing that part off the top of my head from semester 1 knowledge (hence why I forgot the letter involved).

[TrueLight]

lol thats okay... any facts stated should be corrected if wrong so no harm done