Meiosis is a process of cell division that takes place only in sex organs, in order to produce sperm or egg cells. Sperm or egg cells must have half the number of chromosomes of normal, somatic cells, so that when they fuse during fertilization, the result is a zygote with the complete number of chromosomes. For example, human somatic cells have 46 chromosomes (diploid), whereas human sperm or egg cells have 23 chromosomes (haploid). To achieve this halving of chromosome number, meiosis is required.
The difference between mitosis and meiosis
Mitosis is the process of cell division where one cell divides into two cells which are identical to the original cell. This takes place in all our somatic ("normal") cells.
Meiosis is a special form of cell division that only takes place in the sex organs (gonads) of organisms that undergo sexual reproduction, in order to produce sperm or eggs (gametes). Here, the resulting sperm/egg cells are not identical to the original dividing cell, but only have half the amount of chromosomes as our normal cells (haploid).
Meiosis is a special form of cell division that only takes place in the sex organs (gonads) of organisms that undergo sexual reproduction, in order to produce sperm or eggs (gametes). Here, the resulting sperm/egg cells are not identical to the original dividing cell, but only have half the amount of chromosomes as our normal cells (haploid).
The difference between chromatin, chromatid and chromosome
It's easy to confuse these 3 terms! Let's try to clear things up here.
DNA, the blueprint of life, is organized into structures called chromosomes. In prokaryotic cells, chromosomes are circular, whereas in eukaryotic cells, they are linear strands. Different organisms have different numbers of chromosomes: human cells usually have 46 chromosomes, dogs have 78 chromosomes, while kangaroos have only 12 chromosomes!
DNA, the blueprint of life, is organized into structures called chromosomes. In prokaryotic cells, chromosomes are circular, whereas in eukaryotic cells, they are linear strands. Different organisms have different numbers of chromosomes: human cells usually have 46 chromosomes, dogs have 78 chromosomes, while kangaroos have only 12 chromosomes!
Photosynthesis Lab: What to Expect
As mentioned earlier, the rate of photosynthesis should increase when you give the plant more light, more carbon dioxide and the optimum temperature. However, at high light and high carbon dioxide, photosynthesis will reach its maximum rate and won't go any higher.
Photosynthesis Lab: What to Measure?
What to Measure?
Now, how would you measure the rate of photosynthesis?
Again, let's look at the equation for photosynthesis:
Photosynthesis Lab: Set Up
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| Photo of Elodea plant by Kristian Peters (http://www.flickr.com/photos/fabelfroh/) |
A commonly-used plant for such experiments is the Elodea, an aquatic (underwater) plant also referred to as pondweed. You can buy this at aquarium stores.
The set up depends on which question you would like to study.
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