Answer:
The key thing to consider here is that water's expansion when freezing is what allows ice to float. The fact that ice remains on top of water is what prevents lakes and rivers from freezing solid. The layer of ice on top serves to insulate the water underneath from the cold air, meaning that life can continue to survive in bodies of water even if they're totally iced over.
If that were not the case, and ice sank, many of the planet's lakes would not be able to support life in the winter. The polar ice caps would also be very different. Whereas the Arctic is a layer of ice floating on top of water, sinking ice would turn it into a giant ice cube extending all the way to the ocean floor. The Antarctic would experience an encrusting of ice all around the continent. Neither of these would be conducive to life.
So, in short, the world would probably support dramatically less life than it does now. Failures of rivers to flow in winter would likely mean that most regions beyond the subtropics would be nearly barren. People would likely have been constrained to the tropics. The oceans would be much lower due to so much ice being tied up in the poles, and there would probably be much less rainfall. This may have made the development of agriculture as we know it impossible.
So, if there were people at all in such as world, they'd probably still be hunter-gatherers, without civilization as we conceive it
Answer:
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water, In most cases, oxygen is also released as a waste product that stores three times more chemical energy than the carbohydrates. Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth.
Explanation:
Answer:
B. Gametophytes of seedless vascular plants
Answer:
1. Energy.
2. Pellagra.
3. Niacin.
4. Beta carotene.
5. Osteoporosis.
6. Calcium.
7. Epithelial.
8. Intrinsic.
9. Sunlight.
Explanation:
1. Riboflavin and thiamin are important for energy production within cells, including nervous system cells.
2. Pellagra: the niacin-deficiency disease causing dermatitis.
3. Niacin: this vitamin can be produced in the body if enough tryptophan (an amino acid in proteins) is present.
4. Beta carotene: is one of the plant-based forms of vitamin A that must be made active in the body.
5. Osteoporosis: Thinning of bones that occurs in older age and results in serious fractures.
6. Active vitamin D acts on 3 key target organs/tissues in the body to raise the blood calcium levels.
7. Epithelial: Type of tissue that lines and protects the digestive tract and respiratory tract and is maintained by vitamin A.
8. Intrinsic factor, produced in the stomach, is needed for the body to be able to absorb adequate amounts of vitamin B12.
9. Vitamin D can be produced by exposure of the skin to sunlight.
Answer: students drinking coffee
Explanation:
The dependent variable is the one that DEPENDS on what is about to happen. In this situation, whether the students scored higher DEPENDS on if they drank coffee.
So the independent variable would be the fact that they drank coffee.
Hope this helps!