Motor neurons carry impulses to the effectors in the body, which are the muscles or glands that produce a change based on a stimulus sensed by the receptors. The motor neurons "innervate" muscle fibers, which essentially means that they cause them to move. The fewer the muscle fibers associated with a motor neuron, the more precise are the movements of those fibers. Having to control a small number of fibers, the neuron is able to coordinate more dexterous motions. An example of a region where there are not a lot of muscle fibers related to each neuron is in your fingers.
a. respiration of living organisms
D. absorption of CO2 from the atmosphere by ocean water
Squamous cells area one single layer and flattened, this allows for diffusion of oxygen and carbon dioxide to happen easily in the lungs.
Answer:
Charles Darwin
Explanation:
Natural selection, most famously proposed by Charles Darwin, states that when presented with an environmental challenge, some individuals in a species will develop adaptations to face these challenges. Successful individuals will be more likely to mate and their offspring will inherit these adaptive traits, and will continue to pass for generations.
In this sense, plants face the challenge of the cold. Those that adapt to the cold will survive and reproduce, those that can't adapt to the cold will die. Eventually, only plants that can tolerate the cold will survive.
Answer:
- In terrestrial environments: increasing CO2 levels cause an increased photosynthetic rate
- In aquatic environments: increasing CO2 levels cause an increase in water acidity
- In both terrestrial and aquatic environments: increasing CO2 levels lead to an overall increase in the average temperature (global warming)
Explanation:
In terrestrial ecosystems, rising carbon dioxide (CO2) levels increase the rate of photosynthesis (since CO2 is one of the reactants in photosynthesis), thereby also increasing plant growth. Moreover, in aquatic ecosystems, rising CO2 concentrations increase the levels of this gas dissolved on the surface of the oceans. This increases the acidity of the oceans, thereby modifying habitats and food web structures. The increasing acidity of the oceans also reduces the amounts of carbonate, which difficult for aquatic species (e.g., corals) to form their shells/skeletons. Finally, CO2 is a greenhouse gas that contributes to the increase in the average temperature by absorbing solar radiation that would otherwise have been reflected by the Earth's surface, and this increase in the temperature negatively affects life in both terrestrial and aquatic environments.
