Science
This is true because humans can only know so much due to unexplored lands, water depth, and evidence of extinction being hidden.
I’m not sure but I think A
Answer:
a.
Explanation:
The slight positive charges on the hydrogen atoms in a water molecule attract the slight negative charges on the oxygen atoms of other water molecules. This tiny force of attraction is called a hydrogen bond.
Answer:
The above paragraphs describes that how salt- and fresh-water fish regulates their osmoregulation. Hence, the correct answer would be c. have adapted to deal with osmosis.
Osmosis is the process by which solvent's molecule move from region of low concentration (hypo-tonic) to the region of high concentration (hyper-tonic) through a semi-permeable membrane.
In sea-water fishes, the body fluids are hypo-tonic to the surrounding water and thus water is kept moving out of their gills. In order to prevent the excess water loss they need to drink water constantly and excrete concentrated urine.
In contrast, fresh-water fishes body fluids are hyper-tonic to surrounding water and hence, water keeps entering in their body through gills. So, in order to prevent excess dilution they absorb salt from surrounding with the help of gills and also their bodies reabsorb salt from urine.
Answer:
What best describes how transferrin is transported through the erythrocyte plasma membrane is receptor-mediated endocytosis.
Explanation:
The incorporation of transferrin across the erythrocyte membrane depends on a transferrin receptor expressed on the surface of the membrane. The specific receptor recognizes the presence of iron-charged transferrin, transferin diferrica, incorporating it into the cell by endocytosis. Once in the cytoplasm, the iron is dissociated from the transferrin.
Free transferrin is called apotransferrin. The transferrin receptor has a high affinity for transferrin di-ferrica, which facilitates its incorporation by endocytosis, and the release of apotransferrin into the extracellular space.
The other options are not correct because:
<em> A. </em><u><em>Exocytosis</em></u><em> implies the exit of substances from the cell.</em>
<em> B. </em><u><em>Pinocytosis</em></u><em> involves the invagination of the membrane to incorporate soluble substances into the cell.</em>
<em> C. </em><u><em>Phagocytosis</em></u><em> is the incorporation of solid substances by invagination of the membrane.</em>
