The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Answer:
Population is growing rapidly, far outpacing the ability of our planet to support it, given current practices. Overpopulation is associated with negative environmental and economic outcomes ranging from the impacts of over-farming, deforestation, and water pollution to eutrophication and global warming.
Explanation:
Answer:
Amount of DNA in a diploid G2 nucleus after S phase has already undergone DNA replication hence the amount of DNA in a diploid nucleus in G1 would be 200 ng. As the organism is diploid, 200 ng of DNA would be carried on 14 chromosomes.
It causes eutrophication which means that the algae have too much nutrients and take over the pond, use the oxygen so there is not enough left for marine life, which die as a result.
