Archive for the ‘Biology’ Category
Thursday, July 10th, 2008
Implantation of a fertilized blastocyst occurs between 6 and 14 days after sexual intercourse. A blastocyst is the term for a fertilized egg whose cells are rapidly dividing. Normally, sperm must reach an egg within 24 hours of ovulation because the egg won't survive in the fallopian tubes much longer. ...
Posted in Anatomy, Biology, How long does it take | No Comments »
Thursday, July 10th, 2008
Most people after exposure will test positive after between 2 and 12 weeks. There is a small percentage of people who will not test positive until the virus has been in their body for 6 months, so to be absolutley sure that you are HIV free, take the test at ...
Posted in Biology, Education, How long does it take | No Comments »
Tuesday, July 8th, 2008
It takes anywhere from a week to 10 days for the seeds to send up grass shoots. When working from bare ground, the advice I have read says that when these shoots are about 2 to 3 centimeters long, add another layer of grass seed and in approximately one month, ...
Posted in Biology, Education, How long does it take, Plants | No Comments »
Thursday, June 26th, 2008
The difference between DNA and RNA in the most basic way is that DNA is double stranded whereas RNA is single stranded. The next difference is that DNA is made from deoxyribose and RNA is made from ribose. Ribose has a hydroxyl group attached to it, making it less stable. ...
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Thursday, June 26th, 2008
HIV stands for Human Immunodeficiency Virus and it is the virus that causes AIDS; which stands for Acquired Immune Deficiency Syndrome. The main difference being that a person can have HIV without having AIDS, but HIV is what causes AIDS.
The progression of HIV to AIDS is a continuum where AIDS ...
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Thursday, June 26th, 2008
Mitosis refers to duplication of a non sex cell into two diploid cells (diploid means that it has two sets of chromosomes - one from mom and one from dad) and Meiosis refers to the duplication of sex cells only; sperm and egg. Meiosis of one sex cell results in ...
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Thursday, June 26th, 2008
The difference between plant and animal comes down to cell structure. Plants have a tough, cellulose wall and animals don't. Plants have chloroplasts that photosynthesize matter from carbon dioxide and sun. Also, plants take in carbon dioxide to help create plant material and give off oxygen as a byproduct, whereas ...
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Thursday, June 26th, 2008
Prokaryotic organisms are mostly unicellular and much simpler in form and function than eukaryotic cells. Plants and animals have eukaryotic cells to carry out the complicated metabolic functions required to stay alive. Prokaryotic cells are much smaller, they don't have any membrane bound organelles; parts enclosed in a separate sack ...
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