Stamen: The pollen producing part of a flower, usually with a slender filament supporting the anther. Anther: The part of the stamen where pollen is produced. Pistil: The ovule producing part of a flower. The ovary often supports a long style, topped by a stigma.
Biodiversity loss from species extinctions may rival pollution and climate change impacts. Species extinction and loss of biodiversity could be as devastating for the earth as climate change and air pollution. That's the finding of a new study by a group of scientists from nine countries.
Answer:
A source from which organisms generally take elements is called exchange pool (option B).
Explanation:
Options for this question are:
- <em>Food web.</em>
- <em>Exchange pool.</em>
- <em>Reservoir.</em>
- <em>Biotic community.</em>
The term exchange pool is related to the biogeochemical cycles that exist in nature, referring to the source from which elements present in the environment become part of living organisms.
<u>Exchange pools are the biotic components</u> -like animals and plants- of an ecosystem, which determine the passage of elements between living beings. An element can remain as a reservoir (abiotic) in the soil, and then be incorporated into the exchange pool.
Answer:
D. The two students who have two fragments have one restriction site in this region.
Explanation:
The DNA samples from the cheek cells were subjected to digestion with a restriction enzyme. This enzyme is an endonuclease and cuts the DNA at a specific sequence only. This sequence is called a restriction site. If the restriction site is not present in the sample DNA, the restriction enzyme cannot cut it. The presence of one restriction site in the sample DNA would cut it into two DNA fragments.
Similarly, the presence of two restriction sites in each DNA molecule would obtain a total of three DNA fragments per DNA molecule.
