Stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years (for the most massive) to trillions of years (for the less massive), considerably more than the age of the universe. ^
Small, relatively cold, low mass red dwarfs burn hydrogen slowly and will burn for hundreds of billions of years
Massive hot supergiants will live for just a few million years.
A mid-sized star like the Sun will remain on the main sequence for about 10 billion years. Hope tis helps!!
The right option is; Hormones are the chemical signals, which are sent all through the body to monitor other processes of the body.
Hormones are chemical messengers that are secreted from the endocrine glands, and are released directly into the bloodstream, which transports them to tissues and organs to perform their functions. Different types of hormones act on different body function and processes. Hormones influence the body’s functions, including development and growth, cognitive function and mood, sexual function and reproduction, regulation of body temperature and thirst, and food metabolism.
In ecology, allogenic succession is mediated by the abiotic components of the ecosystem, while the autogenic succession refers to the succession, which is mediated by the biotic components of an ecosystem.
A volcanic eruption wiping out an entire island is an example of allogenic succession.
A soybean crop helping in nitrogen fixation, leading to the development of other species is an illustration of autogenic succession.
A tsunami devastating all the living organism in a habitat is an example of allogenic succession.
Oak trees preventing the growth of smaller sun-seeking shrubs is an example of autogenic succession.
Answer: Alveolar surfactant
Surfactant Alveolar
is a type of substance secreted by pneumocytes II (one type of cell that forms the epithelium in the alveolar membrane). This substance is known as an tensioactive agent, decreasing the surface tension within the alveoli.
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