Answer:
A longitudinal study
Explanation:
A longitudinal study can be used to discover relationships between variables that are not related to various background variables. This observational research technique involves studying the same group of individuals over an extended period.
Ileum portion has Peyer's patches but jejunum portion is not having it
Explanation:
Small intestine can be divided into three parts they are ileum , jejunum and duodenum. Small intestine is a long , folded as well as narrow tube that extend from the stomach to the large intestine. Small intestine is that region where digestion takes place, small intestine mainly absorb nutrients from the food. Ileum and jejunum have Brunner's gland but duodenum do not have Brunner's gland. Ileum is having Peyer's patches but jejunum and duodenum is not having it.
Difussion occurs from a high concentrated region to a low concentrated region. The velocity of diffussion is proportional to the differential of concentrations. In the lung arrives blood with low levels of oxygen while the long is rich with fresh oxygen so the oxygen flows from the lung tissues to the blood.
The other tissues consume oxygen continually them they get poor in oxygen and so the oxygen that is in the blood diffuses to the tissue that is poor in oxygen.