Rachel Carson played a key role in the birth of environmentalism in the 20th century.
She became increasingly aware of the harmful facts of insecticide DDT on the environment. This compelled her to write her most famous work Silent Spring and defending herself against attacks from commercial interests.
The book also played an influential part in persuading governments to ban or heavily restrict the use of DDT and similar chemicals that persist in the environment.
Answer:
The correct answer would be a lipid-soluble signal.
Signal transduction refers to the set or cascade of bio-chemical reactions take place in a cell in order to transmit the chemical or physical signal from outside the cell to inside target molecule.
It is usually initiated by receptors present on the membrane of the cell which sense the extracellular stimulus (such as ligand, hormone, pressure, temperature, pressure etc). Once activated, these receptors activate the cascade of reaction which ultimately reaches the target molecule and produces a cell's response.
In contrast, the lipid-soluble signals (such as steroidal hormones, thyroid hormone etc) enter the cell membrane without any hindrance. They directly bind to intra-cellular receptor present in the cytoplasm or on the nuclear membrane.
The hormone-receptor complex then enters the nucleus and act as transcription factor and produces the response in the form of transcription.
False,Neptune is bigger than earth.