A hormone is a molecule that functions as a chemical signal. A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Endocrine hormone molecules are secreted (released) directly into the bloodstream. !
Answer:
i think it is the middle one
B
The answer is true letter a
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: Chloroplast
Explanation:
The presence of chloroplast would have been the last organelle which appeared in the eukaryotic cell. Chloroplast helps in photosynthesis which means prepare food from the inorganic compounds.
But here the cell obtains energy from the organic compounds which states that there is no need of chloroplast in the cell as they obtain energy by hetero tropic mode of nutrition.
Hence, chloroplast is the correct answer.
