D. How light and oxygen levels in water affect the growth of algae within a system over time
The correct answer for this question would be the last option. The statement that best describes the reproductive life cycles of ferns and angiosperms is this: <span>The dominant sporophyte phase in the life cycles of both ferns and angiosperms includes the formation of leaves, roots, and stems. Hope this helps.</span>
Answer:
- Protozoans → would not have survived because they have no way to produce their own food → Heterotrophs
- Algae → would have survived without this food source → Heterotrophs
Explanation:
The protist kingdom is composed of two main groups. The principal difference between them is that algae can produce their own food, while protozoans need to ingest other organisms or organic molecules to survive.
- Algaes are autotroph
- Protozoans are heterotroph
<u>Protozoans</u>:
Microscopic unicellular organisms, eukaryotic and heterotrophs -predators or detritivores-. Most of them are aquatic free-living organisms, but some species are parasites. They feed on<u> bacteria</u>, other organic wastes, and other microscopic organisms. The phagocytosis process is normally used to ingest the food, invaginating their cell membrane.
<u>Algae</u>:
Eukaryotic micro- or macroscopic organisms. Autotroph and photosynthetic. They might be either unicellular or pluricellular. They use sunlight to synthesize organic matter from water, CO₂, and mineral salts. Unicellular ones can be free-living or associate with others to form colonies. They are part of the phytoplankton and are ingested by heterotrophic organisms. Pluricellular algae do not create real tissues but they compose a tale. The depth at which they inhabit depends on the pigments they produce. All of them inhabit fresh or sea waters.
Muscle cramps are caused when the muscle takes longer than normal to relax after a contraction. During contraction, the myosin heads attach on their binding sites on the actin filament and pulls on the filament hence shortening the sarcomeres. For the myosin head to release its binding site on the actin filament, ATP attaches to an active site on the myosin and is hydrolyzed to ADP and Pi. This causes relaxation after a contraction cycle. Cramps, therefore, may be due to depletion of ATP molecule in the muscles cells.
Another reason for cramps may be a high amount of calcium in the muscles that bind to troponin on the actin filaments. This exposes the myosin binding sites longer hence promotes the formation of cross-bridge even when the contraction of the muscle is not intended anymore.