Answer:
<u>a) strong joints with restricted movement.</u>
Explanation:
Joints which are closely fitted cannot allow free movement because movement requires space in the joint so the bones can move in this space. So a closely fitted joint allow restricted or no movement at all. Weak joints with restricted movements are called weak because they are not well fitted closely. Strong joints with restricted movement is closely fitted, one of the example is joints of skull.
Answer:
E. 1/600
Explanation:
Hint:
The probability of fixation of a new neutral mutation is 1/(2N)
Given N as 300
= 1/(2×300)
=1/600
Therefore,
1/600 gives a sure fixation of one allele from the large population
Answer and explanation:
If a human blood cell with a 0.9% solute concentration were to be put into a container of 0% solute solution, the cell would get BIGGER.
<u>The cell contains a </u><u>more concentrated solution</u><u> than the solution in the container</u>. The difference in concentration would produce an <em>osmotic gradient</em> that would cause water from the container to get inside the cell to even the concentrations - this is going to make the cell much bigger because the entering water would bloat the cell.
In this example, the solution in the container is hypotonic in relation to the cell, while the solution inside the cell is hypertonic in relation to the solution in the container. This is why the water will be moving from outside of the cell to the inside of the cell.
There are no choices, I'll assume that the Nereus in the question refers to the underwater vehicle.
Facts about the Nereus
1) It is an HROV or <span>hybrid unmanned autonomous underwater vehicle. Operated underwater but its operator is in a remote location.
2) Built and operated by WHOI or </span>Woods Hole Oceanographic Institution<span>
3) Designed to explore the deepest surveyed point of the ocean worldwide named Challenger Deep.
4) Deepest dive was at 35,768 feet of the Mariana Trench last May 2009.
5) Was lost on May 10, 2014 after it imploded due to pressure in the Kermadec Trench</span>
DDT stands for dichloro-diphenyl-trichloroethane. The first kind of synthetic/artificial insecticides came into use in the 1940s. The earlier usage of DDT include: a) Killing of malarial vectors, b) Combatting Typhus and other insect borne human diseases, c) As a pest control in crops d) as a pest control in garden, live stock production and even at homes.
The negative impact of DDT could be felt for the first time when the pests that were earlier killed by use of DDT have now become pesticides resistant. In the 1950s in USA, the regulatory measures were adopted to reduce the usage of DDTs as its effects as a pesticides were no more long significant and also it was creating detrimental physical and psychological impacts on the human and environment.
It was in 1972 that the U.S. Environmental Protection Agency cancelled the order for banning the usage of DDT based on the adverse impact it produced on the environment, human and other life forms. Since then continuous studies are being conducted to analyse the impact of DDTs. In some later years it was established that DDT is the cause of producing tumors in liver.
Some of the common negative impacts produced by DDT as per the U.S. Department of Agriculture :
a) The non destructive nature – DDT can not be destroyed and thus it remains persistent in the atmosphere
b) It attacks the tissues of living organisms especially the animals and humans ( fatty tissue)
c) It can penetrate the atmosphere to deeper extent.
Now as per the current stuation, The use of DDT is controlled and other alternatives of pest control organisms is being deduced. As per the treaty of Stockholm Convention on POPs (Persistent organic pollutants) , usage of DDT for malarial control is justified but it puts a restrictive use of DDT as pesticides in other areas.
