Molecular genetics questions.

[strawberrykiwi]

If anyone can help me with ANY of these 5 questions, it would be greatly appreciated!!!


1) what is the connection between a chromatid and a replicated DNA molecule?
2)How can all organisms share the same 4 bases DNA and still be so diverse?
3)If a fly has a diploid number of 12, how many chromosomes would there be in each cell at the end of telophase of mitosis?
4) what is the pairing rule for deoxyribonucleic acid?
5) How many chromosomes would normally be found in a human stomach cell?


once again if you know the answer to ANY of these plz post!
thanks =)

[biostudent84]

1. A chromatid is a half of a replicated chromosome (the chromosome is made up of DNA)
2. Bases are read in sets of three, called codons. There are 64 possible codons, which is more than enough to code for the 20 amino acids as well as the Start and Stop commands.
3. 24. Each is replicated, but the cell is not completely divided.
4. A<->T and G<-->C
5. 44 normal, plus 2 sex chromosomes...46 alltogether

Kyle

[strawberrykiwi]

oh my gosh thanks SOOOOOO much biostudent, you rock!!! i actually understand this stuff now so hopefully i'll do OK on the test tuesday. thanks again!

[biostudent84]

lol, all right thanks =) if you need any more help, we'll be here.

[strawberrykiwi]

awesome!! this is the coolest place ever, i'll come back if i have more questions =D
thanks!

[biostudent84]

Lol, please do

[brownpanda]

I believe there are 46 chromosomes everywhere in the human body....

[biostudent84]

I didn't believe I said anything contrary to that =P

[junkyarddawg]

Or as "old folks" like me say 23 pairs. This forum sure would have helped me with my genetics class!!!

[biostudent84]

It is generally still said "23 pairs," but they have become interchangable.

Down's Syndrome is still said to affect Chromosome Pair #21, not Chromosomes 42 and 43...

[brownpanda]

I didn't believe I said anything contrary to that =P

You didn't. strawberrykiwi seemed to suggest that by asking

How many chromosomes would normally be found in a human stomach cell?

Just trying to help clarify things, if she's still around.