Rigid skeletons are formed from materials including chitin (in arthropods), calcium compounds such as calcium carbonate (in stony corals and mollusks) and silicate (for diatoms and radiolarians).
Answer:
Mesophyll cells.
Explanation:
Transpiration is the evaporation of water at the surfaces of the spongy mesophyll cells in leaves, followed by loss of water vapour through the stomata . Transpiration produces a tension or 'pull' on the water in the xylem vessels by the leaves. Water molecules are cohesive so water is pulled up through the plant.
<span>the
end products of aerobic glucose breakdown are carbon dioxide and water;
the end product of anaerobic glucose breakdown is lactic acid</span>
Explanation:
In Earth’s history before the Industrial Revolution, Earth’s climate changed due to natural causes not related to human activity. Most often, global climate has changed because of variations in sunlight. Tiny wobbles in Earth’s orbit altered when and where sunlight falls on Earth’s surface. Variations in the Sun itself have alternately increased and decreased the amount of solar energy reaching Earth. Volcanic eruptions have generated particles that reflect sunlight, brightening the planet and cooling the climate. Volcanic activity has also, in the deep past, increased greenhouse gases over millions of years, contributing to episodes of global warming
Answer:
Carcinogenic
Explanation:
A carcinogenic substance is able to modify or damage the genome in a way which promotes the formation of cancerous cells. Cell cycle checkpoint proteins are very crucial for the progression of normal cell cycle. They check for any anomaly in their designated step and halt the process if it is detected. Repair mechanism is activated and cell cycle does not progress till the damage has been repaired.
Here, the pollutant alters the structure of these proteins such that they lose their function. They are not be able to stop cell cycle from progressing even if there is some damage in the genome. The cell divides and gives rise to more damaged cells. Eventually these cells lose their normal function and just keep dividing due to which their division rate becomes double of the normal rate. It can ultimately give rise to cancer which is why the chemical is carcinogenic.
