Answer:
The correct option is A. Steroid hormones exert their action by entering the nucleus of a cell and initiating or altering the expression of a gene.
Explanation:
Steroid hormones are derived from cholesterol and regulate multiple biological processes. All steroid hormones exert their action by crossing the plasma membrane and by binding with their respective intracellular receptors. They stimulate cell growth in a very different way, their lipophilic nature gives them the ability to cross lipid barriers, so, without the need for extracellular signals, these hormones can easily enter the cell, cross the cytoplasm and reach the nucleus. There they bind to specific receptors that are associated with DNA promoter regions, modifying their structure and promoting the expression of the genes under their control.
Answer:
The microorganism creates its own energy.
Explanation:
Based on the pattern of nutrition, a living organism can either be autotrophic or heterotrophic. Autotrophic organisms are those organisms capable of synthesizing its own food or energy source using light (photosynthesis) or chemicals (chemosynthesis). Heterotrophs, on the other hand, cannot synthesize their own food, hence, they depend on other organisms for energy.
According to this question, a researcher claims that a newly discovered microorganism is an autotroph. For this claim to be true, this means that the microorganism must be capable of CREATING ITS OWN FOOD/ENERGY either by photosynthesis (light) or chemosynthesis (inorganic chemicals).
The three substances that cause a double displacement reaction to occur are:
(i) Ionized compounds. These are usually water.
(ii) A gas that bubbles out a solution.
(iii) A precipitate.
In double displacement reaction is where two new compounds are formed when two parts of two compounds switch places. For example; when sodium chloride combines with silver nitrate, the two new compounds formed are Sodium nitrate and silver chloride reason being sodium and silver switched places.
