Answer:
The photosynthetic rate refers to a determination of maximum rate at which leaves possess the tendency to fix carbon at the time of photosynthesis. The simple way by which the photosynthetic rate can be determined is by measuring the concentration of carbon dioxide produced.
It is known that the concentration of carbon dioxide, light intensity, and temperature are the three main elements, which affect photosynthesis. The enhanced concentration of carbon dioxide and higher light intensity results in higher photosynthetic rates.
In the given case where Elodea is used to study photosynthesis, it can be seen that at high light intensities, the concentration of bubbles increases as there is an elevation in the concentration of carbon dioxide.
I think the correct answer is ions.
An action potential occurs when a neuron sends information down an axon, away from the cell body. A neuron that emits an action potential, or nerve impulse is said to fire. These action potentials are generated by special types of voltage hated ion channels that are embedded in the plasma membrane of the cell.
C) balance
Explanation: ruler shows length and the other 2 are used for liquids
Answer:
Na+ only
Explanation:
Depolarisation of membrane refers to the change in the resting membrane potential of the membrane of a cell which is usually -70mv to a more positive value.
This value changes when the positive ions move inside the cell which increases the positive charge inside the cell.
In the myocardial cell, the sodium ions move inside the cell which changes the potential towards the more positive side as a result of which the signals for contraction arises.
Thus, Na+ only is correct.
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.
