Answer:
Earliest- gametophyte dominance, sporophyte dependence
Middle- sporophyte dominance, gametophyte independence
Recent- sporophyte dominance, gametophyte dependence
Explanation:
The life cycle of plant alternates between the two phases: the haploid gametophyte which produces gametes and the diploid sporophyte which produces spores. The evolution of land plants shows how these are dependent on each other in terms of the requirement of nutrition.
In bryophytes, the gametophyte is the dominant phase on which the sporophyte depended. Later in pteridophytes, the sporophyte became dominant which is present in the later evolved groups namely the gymnosperms and the angiosperms. The gametophyte was independent on the sporophyte but in angiosperms and gymnosperms, it is dependent.
When we talk about evolution we come across the process of natural selection. Genetic variation is always required for the natural selection. A change or variation in the genes may help the individuals in a population to better adapt to the environment. Such changes may be brought by mutations or random mating in the population. Such variations help in the survival of the population by allowing them to adapt to changing environmental conditions.
Answer:
it is unclean
Explanation:
fish that have non-shedding, non-overlapping, diamond-patterned, or imbedded scales should be considered unclean.
Ecosystems equilibrium is when populations of organisms in the ecosystem are balanced.
Tight-fitting respirators must seal to the wearer’s face in order to provide expected protection. This includes disposable respirators (also called “filtering facepieces”). Therefore, fit testing is required in the US by the Occupational Safety and Health Administration (OSHA) before a user wears a mandatory respirator on the job, and must be assessed at least annually. In addition, fit tests should be performed:
Whenever a different size, style, model or make of respirator is used.
When any facial changes occur that could affect fit, such as significant weight fluctuation or dental work.
A good fit means the respirator will seal to your skin. A respirator can only work when air passes through the filter. Air will take the path of least resistance, so if the seal isn’t there, the air will go around rather than through the respirator – and therefore lessen the protection.
Safety glasses, hearing protection, face shields, hard hats and coveralls can all vie with a respirator for real estate on a person’s face, head or body. For instance, if a half face respirator doesn’t fit well (especially if it’s too large), it can overlap with glasses. The more that happens, the more fogging can potentially occur on glasses, and the more likely it is that they’ll interfere with the respirator’s seal.
