Answer:
Flatworms are beings that do not have a heart, veins, arteries, capillaries, hemolymph, or some type of circulatory fluid. Their circulation occurs between cells or intercellularly and they are responsible for transporting substances by diffusion from cell to cell.
Explanation:
Flatworms are considered multicellular eukaryotic organisms. This implies that in their cells they have a cellular nucleus, in which the DNA is contained, structuring the chromosomes. Likewise, they are made up of several types of cells, each one specialized in a specific function. They lack a structured circulatory system as such. Because of this they do not have specialized structures such as a heart or blood vessels, however, the circulation of certain substances is established between their cells. This is done thanks to the diffusion process. Substances pass from one cell to another through this process.This does not apply to all flatworms, since in some species of bog and digenae there is a certain organization and some very small conducting vessels known as the endolymphatic system, the which forms a kind of plexus in the parenchyma.It should also be noted that some species do not even have a digestive system, being the digestive tract the one in charge of digestive functions and the distribution of the nutrients they receive.
➜ Fission (binary and multiple), regeneration and fragmentation are considered as methods of asexual reproduction because all of them involve only one parent and gametes are not formed in them. New individuals produced after cell division are always genetically identical or clone to their parents.
Bacteria cells, I believe so.
Due to huge effect use of Drought the population of animal get extinct.
Explanation:
Droughts can have a severe impact on the extinction of animal populations, specifically in Arid and Semi environments. Different type of climate changes can accelerate the dying of particular species or animal population.
For extinction of population and also species Droughts play vital role. Droughts are one of such severe climatic change that leads to the extinction of species. Some life traits of specific Species make it vulnerable to drought.