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.
The right answer is True.
At the global level, climate change will contribute to the disruption of the Earth's natural ecosystems, which could lead to the extinction of wild animal species and plants. It is mainly the impact of climate change on habitat and ecosystems that will dictate the impacts on biodiversity (by expanding them or the opposite).
Climate change will profoundly affect agricultural and forestry production. The effects in terms of production potential will be very variable depending on the regions and plant cover. They can result in an overall tendency for moderate stimulation in temperate climates and for limited warming at 2 ° -3 ° C.
