In parthenogenetic reproduction, the egg cell develops into a new or ganism without fertilization. It is clear that the most essential feature of parthenogenesis, absence of fertilization, causes important alterations of basic nature in cytological, as well as in genetic, respects.
Answer:
<u>True</u>
Explanation:
In cells, energy is obtained from food through the process of cellular respiration. In mitochondria, this occurs through aerobic respiration- here, cells breakdown sugars like glucose into carbon dioxide and water and energy in the form of ATP or adenosine triphosphate.
In cellular aerobic respiration:
C6H12O6 (glucose) + 6 O2 → 6 CO2 + 6 H2O + ≅38 ATP
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.
B.metric system of measurement.
a system of physical units ( SI units ) based on the meter, kilogram, second, ampere, kelvin, candela, and mole, together with a set of prefixes to indicate multiplication or division by a power of ten.
Answer: Vagovagal reflex control circuits in the dorsal vagal complex of the brain stem provide overall coordination of gastric, small intestinal, and pancreatic digestive functions.
Explanation:
