Search found 728 matches

by biostudent84
Tue Nov 15, 2005 10:24 pm
Forum: Human Biology
Topic: Need help on Stem Cells.... pleease!
Replies: 2
Views: 1768

A "line" of stem cells is a group of stem cells with identical genetic material. The "signals" are not that well understood. In a developing human fetus, they are not understood at all. All that we know so far is that if a stem cell is placed into a culture of specialized cells, the stem cells will ...
by biostudent84
Tue Nov 15, 2005 10:22 pm
Forum: Human Biology
Topic: Ovulation/menstruation question
Replies: 8
Views: 4578

14 days is the AVERAGE. Everyone's body is different. It could vary anywhere between 7 and 21 days after menstruation.
by biostudent84
Tue Nov 15, 2005 10:21 pm
Forum: Human Biology
Topic: Birth control
Replies: 28
Views: 15099

If you are worried about side effects, use a condom. It has absolutely no side effects and protects you from STD's(just in case your innocent new girlfriend ain't that innocent ) Uhh. Condoms keep 99.99% of the sperm inside it. 0.01% usually gets through because of the size of the holes in the cond...
by biostudent84
Sun Nov 13, 2005 4:59 pm
Forum: General Discussion
Topic: New embryonic stem cell possibility?
Replies: 2
Views: 2031

It sounds like it would take a lot of work to do so. Also...it would still be attacked by the fundamentalist groups because technically it will be an embryo...
by biostudent84
Sat Nov 12, 2005 6:42 pm
Forum: Human Biology
Topic: advantages of human reproduction system?
Replies: 8
Views: 11899

An other thing is that woman are fertile once a month, when most animals have much more limited reproductive period: advantage: more offspring That also helps conserve eggs and extend the overall time when a woman is fertile in her entire lifetime. Instead of being extremely fertile for a few years...
by biostudent84
Sat Nov 12, 2005 4:37 pm
Forum: Human Biology
Topic: Colors of blood vessels
Replies: 8
Views: 31174

hurly wrote:All bloodvessels carries oxygen, don't they?


Yes. Oxygenated blood carries between 100 and 95 mmHg of oxygen. Deoxygenated blood carries about 40 mmHg of oxygen.
by biostudent84
Sat Nov 12, 2005 4:36 pm
Forum: Human Biology
Topic: advantages of human reproduction system?
Replies: 8
Views: 11899

Err....it sounds like the teacher is asking for advantages of the actual human reproductive system...not the advantage to the idea of sexual reproduction. An advantage off the top of my head is that it is "fun" therefore making humans more apt to reproduce. A disadvantage is that most offspring conc...
by biostudent84
Fri Nov 11, 2005 9:27 pm
Forum: Genetics
Topic: Greg Mendal
Replies: 11
Views: 7579

He was actually born in what is present day Czech Republic.
by biostudent84
Fri Nov 11, 2005 9:21 pm
Forum: Human Biology
Topic: Matching blood groups
Replies: 22
Views: 23199

why can O donate to A --> thus: why can A receive O. You also must remeber: blood clotting occurs when the receiver produces agglutinins against the donated bloodgroup --> O doesn't contain any agglutinogen and therefore can be donated to blood type A patient (which produces agglutinine B but there...
by biostudent84
Fri Nov 11, 2005 1:37 pm
Forum: General Discussion
Topic: Nutrional Relationships
Replies: 12
Views: 6825

A food chain is just one path traced along the food web. :)
by biostudent84
Fri Nov 11, 2005 12:37 pm
Forum: Human Biology
Topic: Matching blood groups
Replies: 22
Views: 23199

It is the presence of conflicting agglutinins that cause the clotting, therefore making transfusion impossible. The red blood cells in type O individuals have no agglutinins in the first place, therefore do not cause potential for clotting.
by biostudent84
Thu Nov 10, 2005 6:27 pm
Forum: Cell Biology
Topic: rbc survival ?
Replies: 21
Views: 12529

How can it use O2 without any metabolic activity? Actually, RBC's are able to make energy. They are able to carry out the first state of Glycosis to make 2 net ATP's, as this stage is carried out in the cytoplasm, not in the mitochondria. And if memory serves, blood cells only remain in the blood s...