The trends that shows the increasing use of renewable energy are:
- Houses and cars powered by solar energy
- Use of geothermal energy in areas with hot water springs
- Construction of wind energy farms in sea
- Research for cheaper and efficient material for solar cells and batteries
- Construction of dams to harvest kinetic energy of flowing water
- Research for alternative biofuels from the leftover husk of crops.
Answer:
Did alleles for drug resistance occur in bacterial populations that afflict humans, prior to the widespread use of antibiotics in medicine and agriculture? a. No—mutations for drug resistance occur in response to antibiotic use. ... Yes—alleles for resistance arise due to random mutation, so are always present.
Explanation:
Differentiation in plants refers to the processes by which distinct cell types arise from precursor cells and become different from each other. Plants have about a dozen basic cell types that are required for everyday functioning and survival. Additional cell types are required for sexual reproduction. While the basic diversity of plant cell types is low compared to animals, these cells are strikingly different. For example, some cells such as parenchyma cells retain the potential to respond to environmental and/or hormonal signals throughout their life and, under the right conditions, can be transformed into another cell type (transdifferentiation). Other cells such as the water-conducting vessel elements undergo cell death as part of their differentiation pathway and thus can never transdifferentiate to another cell type
Read more: http://www.biologyreference.com/Co-Dn/Differentiation-in-Plants.html#ixzz54pAhWVdn
*Given
Percent of the wolves which are female - 55%
Percent of the wolves which hunt
in medium-sized packs - 20%
Percent of the wolves which are both
female and hunt in medium-sized
packs - 15%
*Solution
<u>Assuming that there is a total of one hundred wolves in the species, </u>
1. Since percent (%) means "per 100" or "for every 100" then,
a. The number of female wolves is
(55 female wolves / 100 wolves) * 100 wolves total = 55 female wolves
b. The number of wolves that hunt in medium-sized packs is
(20 wolves / 100 wolves) * 100 wolves total = 20 wolves
Note that the 20 wolves is a mixture of male and female wolves.
c. The number of female wolves that hunt in medium-sized packs is
(15 female wolves / 100 wolves) * 100 wolves total = 15 female wolves
2. Because there is a total of 55 female wolves in the species, and 15 of these wolves hunt in medium-sized packs, then the number of female wolves that do not hunt in medium-sized packs is,
55 female wolves total - 15 female wolves hunting = 40 female wolves not
in medium-sized packs hunting in medium
sized packs
3. To find the proportion, we can express the answer in terms of percent (%) or in fraction, which is usually how proportions are expressed.
For every 100 wolves, there are 40 female wolves that do not hunt in medium-sized packs. This can be expressed as a proportion of
<span> <u> 40 </u>
</span> 100
and simplified by dividing both the numerator and denominator by 10, we get,
<span><u> 40/10 </u>
</span> 100/10
<span><u> 4 </u>
</span> 10
When this is expressed in percent, we multiply the fraction or proportion by 100% to get,
<span><u> 4 </u> x 100% = 40%
</span> 10
Thus, the proportion of female wolves that do not hunt in medium sized packs is 4/10 or 0.4. When expressed as percent, this is 40%.
Answer:
C. Desertification.
Explanation:
This is mainly caused by overgrazing and other human and natural activities in this areas. When desertification happens in a land area, it hampers the land ability to support life; affecting wild species, agricultural crops, domestic animals and people. Its negative effect includes famine of the inhabitants, also mass migration, as it can also cause extinction of some organisms or species.
