It’s easy to confuse these 3 terms! Let’s try to clear things up here. Chromatin is basically a long strand of DNA, coiled around proteins. This sort of structure allows DNA that is really, really long (up to 2m!) fit into a tiny nucleus of a cell (only 5um). During cell division (S phase), this [...]
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. For more details, check this page on photosynthesis: http://click4biology.info/c4b/3/Chem3.8.htm (I will eventually get [...]
What to Measure? Now, how would you measure the rate of photosynthesis? Again, let’s look at the equation for photosynthesis: CO2 + H2O + light –> O2 + glucose There are 2 things we can quickly measure in this experiment (the dependent variables): amount of oxygen produced, or, amount of carbon dioxide used. If the [...]
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. In general, the plant is placed in a test tube filled with diluted sodium bicarbonate solution (1%). Sodium [...]
Here are some ideas for planning experiments for studying plant photosynthesis. Remember that the simple equation for photosynthesis is: CO2 + H2O + light –> O2 + glucose There are many questions you can ask about photosynthesis, such as: Does light intensity affect the rate of photosynthesis? Does temperature affect the rate? What about levels [...]
Cytokinesis is the final stage in the cell cycle. The cytoplasm of the dividing cell is separated in two. The way this happens is different for animal and plant cells. In animal cells, the cell forms a contractile ring in the middle of the dividing cell. As the ring contracts, it creates a cleavage furrow, [...]
Cells spend most of their time (90%) in interphase. However, they are not just “resting”, but preparing for the next division. The first part of interphase, the G1 phase (Gap 1), is the period during which cells are growing, synthesizing proteins and making more organelles. Cells need to double their organelles and size before dividing, [...]
Cell Theory states that cells come from pre-existing cells. What does this mean? Our body is made up of billions of cells, and all of them originate from only TWO basic cells – the sperm and egg. To get from 2 cells to a billion, these 2 cells divide many many MANY times. A lot [...]
Test for oxygen : Gas collected is able to relight a glowing splint (light a wooden splint, blow it out and then insert it quickly into the gas chamber) Test for carbon dioxide : Bubbling carbon dioxide through lime water (calcium hydroxide) makes it cloudy due to solid precipitates of calcium carbonate. Ca(OH)2 (aq) + [...]
