Homework Help

Human Anatomy, Physiology, and Medicine. Anything human!

Moderators: Leonid, amiradm, BioTeam

Post Reply
redfoxindigo
Garter
Garter
Posts: 4
Joined: Thu Apr 27, 2006 1:12 am

Homework Help

Post by redfoxindigo » Thu Apr 27, 2006 1:28 am

I've been working on this Unit for 3 weeks now and some of the questions they ask I just cannot find the answer to. I've been over 3 different text books and the internet and i'm just not finding them. Maybe I''ve already found the answer and just don't know it, but do you think anyone could help?

The questions I'm having trouble with are:

1. What would probably happen if a small group of cells broke off of a human blastula?

I'm thinking the answer is that you would get twins...am i right? I've searched but have not gotten any definit answers, but it seems like the most likely answer.

2. Both egg and sperm cells donate 23 chromosomes to the zygote in human reproduction. What else is donated by the egg cell?

If anyone can help me out here that would be great.

User avatar
mith
Inland Taipan
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN
Contact:

Post by mith » Thu Apr 27, 2006 1:37 am

I believe mitochondria for #2
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

User avatar
victor
King Cobra
King Cobra
Posts: 2668
Joined: Sat Apr 30, 2005 12:01 pm
Location: Yogyakarta, Indonesia..
Contact:

Post by victor » Thu Apr 27, 2006 3:21 pm

I think your answer for #1 will occur when it's in Morula stadium...
Q: Why are chemists great for solving problems?
A: They have all the solutions.

pdavis68
Death Adder
Death Adder
Posts: 57
Joined: Mon Apr 03, 2006 8:37 pm

Post by pdavis68 » Sat Apr 29, 2006 12:22 pm

For #1, Identical twins will develop if a small group of cells breaks off within 4-12 days of fertizilization. If it happens after 12 days, you get conjoined twins.

Fraternal twins result from two separate eggs being fertalized, so there's no split in that case.

The previous answer for #2 is correct as well. The sperm and egg contribute to the nuclear material but the egg alone contributes the mitochondria and mitochondria DNA.

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 2 guests