Answer: As a body cell grows, the ratio of SURFACE AREA to volume INCREASES. Before it grows to large, a cell will divide into two DAUGHTER cells. So that each new cell receives its own genetic instructions, the cell REPLICATES or copies, all of its DNA.
Explanation:
S phase
M phase (mitosis) is usually followed by cytokinesis. S phase is the period during which DNA replication occurs. The cell grows (more...) The duration of these cell cycle phases varies considerably in different kinds of cells.
Answer:
Carbon dioxide is a gas which is released in the atmosphere as greenhouse gas, burning of fossil fuel, released in respiration process. Rise in the levels of carbon dioxide and other gases has resulted in increase in global temperatures. Increase in carbon dioxide and temperatures are responsible for weather fluctuations and global warming.
Weather fluctuation means untolerated heat and lack of precipitation or rain. Weather fluctuations will affect seasons. Seasons are necessary for maintaining the life cycle of organisms. Inappropriate seasons due to climatic change will affect the life of living organisms.
Global warming is an issue which is mainly due to release of hot heat trapping gases from green house and other sources, increasing the atmospheric temperature. This will result in melting of ice from glaciers in world. The inhabiting animals living in the glaciers will suffer a lot from this as they cannot tolerate warm climatic conditions.
Decent from a common ancestor; natural selection.
TEMPURATURE:
Raising temperature generally speeds up a reaction, and lowering temperature slows down a reaction. However, extreme high temperatures can cause an enzyme to lose its shape (denature) and stop working.
pH:
Each enzyme has an optimum pH range. Changing the pH outside of this range will slow enzyme activity. Extreme pH values can cause enzymes to denature.
DIFFERENT SUBSTRATES:
Increasing substrate concentration also increases the rate of reaction to a certain point. Once all of the enzymes have bound, any substrate increase will have no effect on the rate of reaction, as the available enzymes will be saturated and working at their maximum rate.
I got these explanations from khan academy :)