Answer:
The correct answer is - zero or 0%.
Explanation:
The fertilization in flowering plants takes place by fusing the pollen of one plant or flower with the ovum of another plant or flower of the same species normally and form a zygote. The zygote gets an equal amount of genetic material from both parent plants by the process f exchange of the genetic material.
The ovum or the egg cell of the plant is considered as the mother and the mother is responsible for the chloroplast And mitochondria of the progeny so in this case, the ovum and egg cell comes from the only plant Q thus, the percentage of chloroplast genes provided via Plant R is 0%.
Abiotic factors include sunlight, temperature, moisture, wind or water currents, soil type, and nutrient availability. Ocean ecosystems are impacted by abiotic factors in ways that may be different from terrestrial ecosystems.
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.
Answer:
we dont but when we fish in the reef it gives us more fish faster but people to lazy to take n' hour longer and not destroy the reef
Explanation:
Answer:1
Explanation:Because gravity always pulls you down even when your standing on an object.
