The nutrients get to the cells in a flatworms solid acoelomate body by diffusion process. Flatworms feed primarily on protozoa and bacteria, smaller worms and tiny organisms, dead or alive, that they come across. Based on the species of the flatworms , they also consume plant materials. They rely on diffusion to transport oxygen and nutrients to their internal tissues.
Speciation<span> is the </span>evolutionary<span> process by which biological populations evolve to become distinct </span>species<span>. The biologist </span>Orator F. Cook<span> coined the term 'speciation' in 1906 for the splitting of lineages or "</span>cladogenesis," as opposed to "anagenesis<span>" or "phyletic evolution" within lineages.</span>
Answer:
rice cultivation.
Explanation:
There are two methods of sowing a crop in the field i. e. sowing of seed and transplanting. Seeds sowing in the field is used for almost all the crops except rice in which transplantation is done. In transplanting method, plants are grown inside a nursery and when the plant reaches to a certain height, it is transported to the field. This method is done in the cultivation of paddy rice because water is present at a certain height in the field and rice is the only crop in which roots respire in water.
The pleural cavity is the thin fluid-filled space between the two pulmonary pleurae (known as visceral and parietal) of each lung. A pleura is a serous membrane which folds back onto itself to form a two-layered membranouspleural sac. The outer pleura (parietal pleura) is attached to the chest wall, but is separated from it by the endothoracic fascia. The inner pleura (visceral pleura) covers the lungs and adjoining structures, including blood vessels, bronchi and nerves. The pleural cavity can be viewed as a potential space because the two pleurae adhere to each other (through the thin film of serous liquid) under all normal conditions.