<span>A mature sporophyte produces spores by meiosis, a process which reduces the number of chromosomes to half, from 2n to n. Because meiosis is a key step in the alternation of generations, it is likely that meiosis has a fundamental adaptive function. The nature of this function is still unresolved (see Meiosis), but the two main ideas are that meiosis is adaptive because it facilitates repair of DNA damages and/or that it generates genetic variation.
The haploid spores germinate and grow into a haploid gametophyte. At maturity, the gametophyte produces gametes by mitosis, which does not alter the number of chromosomes. Two gametes (originating from different organisms of the same species or from the same organism) fuse to produce a zygote, which develops into a diploid sporophyte.</span>
Answer:
cell wall
Explanation:
the cell wall helps fighting any bacteria that tries to infect the cell itself.
The estimated daily basal metabolic rate for a man who weighs 150 lb is 1636 kcal.
Basal metabolic rate is the rate of energy expenditure per unit time by endothermic animals at rest. Metabolism comprises the processes that the body needs to function. It is the amount of energy per unit time that a person needs to keep the body functioning at rest. Any increase to the metabolic weight, such as exercise, will increase the basal metabolic rate.
Four unifying principles form the foundation of modern biology<span>: cell theory, evolutionary theory, the gene theory and the </span>principle<span> of homeostasis. These </span>four principles<span> are the founding principles of each category of biology</span>
19.69 million barrels per day.
