Biology Unit 4 Questions Megathread

[BoredSatan]

To determine whether the eye colour of the drosophila melanogaster is genetically linked?

and to determine to type of linking ie autosomal or sex linked?

and to see which colour is recessive/dominant?

thats about all i can think of

[simpak]

To determine the pattern of inheritance for the gene associated with determination of eye colour in Drosophila melongaster would be the proper aim - pattern of inheritance kind of covers all of the above ^.

[epinephrine]

Thank you

[Kaille]

can some spots of microarrays have both the green and the red fluorescent labels?

[WhoTookMyUsername]

Di chromosomes typically exist in somatic cells as 2 chromatids or 1 chromatid per chromosome?

[pi]

Di chromosomes typically exist in somatic cells as 2 chromatids or 1 chromatid per chromosome?

I think its about half-half. Chromosome exist as one chromatid per chromosome during G1 of interphase, which is roughly half of the overall cell-cycle. Not 100% sure though, but that's what I remember

[WhoTookMyUsername]

Yeah that makes sense. I think g1 is only one third of total though (s phase, g2) so it's probably lower to one third. Thanks pi

Another question - is there 1 % coding DNA in humans or in all eukaryotic organisms ( roughly )?

Moderator action: removed real name, sorry for the inconvenience

[Mr. Study]

What is Genome Phylogeny?
What are some patterns in Hominid Evolution?
What is Stem Cell differentiation?

I really don't want to be too demanding but if you could also post any sources, at all, I would really appreciate it.

Thanks, I apologize if they're 'noob' questions but I would love clarification.

[WhoTookMyUsername]

can mitotic division result in two kinds of cells? E.g. Can a cell at the end of a muscle divide into a skin cell and muscle cell ?

[Ravit]

could someone explain the consequences to protein synthesis of the prokaryotic chromosome being free in the cytoplasm?
i thought there is a probability of some of the gene on the chromosome being mutated by chemicals which enter the cell or by enzymes in the cytoplasm.
Does anyone have any better answers?
BTW this is a queston from biozone pg 184

[Russ]

Working backwards

could someone explain the consequences to protein synthesis of the prokaryotic chromosome being free in the cytoplasm?
i thought there is a probability of some of the gene on the chromosome being mutated by chemicals which enter the cell or by enzymes in the cytoplasm.

It's free in the cytoplasm, so yeah, it is exposed but that isn't particularly related to translation. What is significant is that the processes of transcription and translation can be coupled, as there is no requirement to export the mRNA from the nucleus. This means that as an RNA transcript is produced, a ribosome can attach and immediately begin producing a polypeptide.

can mitotic division result in two kinds of cells? E.g. Can a cell at the end of a muscle divide into a skin cell and muscle cell ?

Not normally.

What is Genome Phylogeny?
What are some patterns in Hominid Evolution?
What is Stem Cell differentiation?

No sources sorry, unless you want to cite my memory lol

Genome phylogeny is just a way of measuring the interrelatedness of different species. So the genomic differences between two different strains of E. coli (eg ETEC, EHEC, EPEC etc.) are used to plot them on a phylogenic tree - a gigantic diagram that shows how far apart they are evolutionarily.

nfi, i hate evolution

Stem cell differentiation is the process by which a stem cell turns into a specific type of cell. A stem cell has the potential to be any type of cell in the body when it divides. In contrast, a muscle cell will turn into a muscle cell. So the differentiation process is what happens to the stem cell to instruct it to become a muscle/skin/cardiac/brain cell (etc.)

[Inside Out]

when does cell differentiatioin occur in interfase and what phase do centrioles replicate

[WhoTookMyUsername]

centrioles replicate in G2
Edit: q 0 : can someone explain the action of dna and rna primase? Not sure about their specific action ( which does what)?


Got a few quick questions 

1) Teacher said that there are 4 haploid cells from meiosis. With ova this is not the case, is his definition wrong, or are the polar bodies considered as 'cells' in this definition?

2) do X and Y pair up ? and how?

3) Is bacterial DNA always ds? Is it always attached to plasma membrane at one point ( at least ) ?







4)
HOW many centrosomes are in each cell (and during cell division?)

Are there 1 in every cell G1 and 2 at G2?

Some sources say 1 centroSOME moves to each pole in cell divison,
while another sources says 1 centrIOLE moves to each pole in cell division, i belive the former is correct or else daughter cells wouldn't each have full centrosome.

Also , are centrioles by themselves regarded as organelles?

Thanks  a lot  XD

and yes, just started studying for Unit 4 but have to make up for lost time, i'm sure you've missed all my questions Russ and others

[Mr. Study]

Working backwards

could someone explain the consequences to protein synthesis of the prokaryotic chromosome being free in the cytoplasm?
i thought there is a probability of some of the gene on the chromosome being mutated by chemicals which enter the cell or by enzymes in the cytoplasm.

It's free in the cytoplasm, so yeah, it is exposed but that isn't particularly related to translation. What is significant is that the processes of transcription and translation can be coupled, as there is no requirement to export the mRNA from the nucleus. This means that as an RNA transcript is produced, a ribosome can attach and immediately begin producing a polypeptide.

can mitotic division result in two kinds of cells? E.g. Can a cell at the end of a muscle divide into a skin cell and muscle cell ?

Not normally.

What is Genome Phylogeny?
What are some patterns in Hominid Evolution?
What is Stem Cell differentiation?

No sources sorry, unless you want to cite my memory lol

Genome phylogeny is just a way of measuring the interrelatedness of different species. So the genomic differences between two different strains of E. coli (eg ETEC, EHEC, EPEC etc.) are used to plot them on a phylogenic tree - a gigantic diagram that shows how far apart they are evolutionarily.

nfi, i hate evolution

Stem cell differentiation is the process by which a stem cell turns into a specific type of cell. A stem cell has the potential to be any type of cell in the body when it divides. In contrast, a muscle cell will turn into a muscle cell. So the differentiation process is what happens to the stem cell to instruct it to become a muscle/skin/cardiac/brain cell (etc.)

Thank you very much for that! Don't worry about the sources.

[lexitu]

centrioles replicate in G2
Edit: q 0 : can someone explain the action of dna and rna primase? Not sure about their specific action ( which does what)?


Got a few quick questions 

1) Teacher said that there are 4 haploid cells from meiosis. With ova this is not the case, is his definition wrong, or are the polar bodies considered as 'cells' in this definition?

2) do X and Y pair up ? and how?

3) Is bacterial DNA always ds? Is it always attached to plasma membrane at one point ( at least ) ?







4)
HOW many centrosomes are in each cell (and during cell division?)

Are there 1 in every cell G1 and 2 at G2?

Some sources say 1 centroSOME moves to each pole in cell divison,
while another sources says 1 centrIOLE moves to each pole in cell division, i belive the former is correct or else daughter cells wouldn't each have full centrosome.

Also , are centrioles by themselves regarded as organelles?

Thanks  a lot  XD

and yes, just started studying for Unit 4 but have to make up for lost time, i'm sure you've missed all my questions Russ and others

RNA primase works in a similar enough way to DNA polymerase, adding RNA nucleotides alongside a DNA strand in a 5' > 3' direction. It's useful because it doesn't need a strand to add on to. DNA polymerase does, so RNA primase catalyses primer synthesis so that DNA polymerase can do its thing. I'm assuming you know a bit about what it does, let me know if that's unclear.

1) Yes that is true as far as I know.

2) X and Y pair up because they have certain regions that are homologous.

3) I'm no expert on bacteria, but to answer the first part I think in the majority of cases yes.