Ecosystems disturbed by a nature will be eventually restored unless it's a really big cataclysm, but most of the ecosystems are now a human caused disturbance. For example there are plenty of species which are already extinct or nearly extinct because of hunting industry.
B. The U.S stock market crash and Franklin D Roosevelt’s policies
RFLP or Restriction Fragment Length Polymorphism exploits the variation of homologous DNA (Deoxyribonucleic Acid) sequences. This technique is frequently used in different types of analysis such as genotyping, paternity tests, forensics, hereditary disease diagnostics, and many others. In diagnosing diseases, PCR is use to find the DNA of pathogens in small amounts to diagnose hundreds of genetic diseases. While in forensic investigations, PCR can give a probably ID from 20 cells.
Answer;
Transport of substances
Explanation;
-Veins have vascular tissues, that is the xylem and the phloem. Xylem tissue transports water and mineral salts to the leaf, while phloem transports manufactured food from the leaf to other parts of the plant.
-Leaves need water for photosynthesis and the water is transported from roots to leaves through xylem.
-Veins are spread all over the leaves ,so they can easily transport water to all the cells of leaves.
-After the completion of photosynthesis in a chloroplasts, glucose is formed which may be used for cellular respiration or stored in form of starch. Phloem transports the glucose to other parts of the plant for cellular respiration;