Membranes control whats good or whats bad to get inside the cell, basically it allows good things to pass into the cell and bad things to stay out
Evidence for evolution, in other words evidence of common descent, include fossils, which have shown a (fairly) steady change in morphology over time for some species. An example would be horse hooves: we have fossils that show when they were still three toed, then two toed, then one toe in our present day horses. Another piece of evidence is vestigial organs. An example of vestigial organs is wings in some flightless birds, such as the kiwi. Their ancestors used it in order to fly across the marine barrier into New Zealand, but natural selection and random genetic drift made them quickly lose the ability to fly. Nonetheless, they still have their wings, however small. It can be assumed that eventually, their wings would be reduced to small stubs fused to other nearby bones, as has been observed in their cousins.
Answer:
Parotid glands are the largest salivary gland. Each gland is approximately 6 cm long and 3-4 cm wide and can weigh up to 30 grams. They are located within each of our cheeks. In our oral cavity they are responsible for the secretion of about 20% of saliva. This saliva is known as serous i.e. more liquid and fluid. It helps in the first phase of the digestion of food, facilitate mastication "chewing". These glands secrete protein-rich fluid which is a suspension of alpha-amylase enzyme.
TOPOGRAPHY AND ELEVATION .
Linnaeus. Carolus Linnnaeus is a Swedish naturalist whose lasting achievement is binomial nomenclature; it is a system of naming and classifying plants and animals according to genus and species.