<span>How many openings are in the digestive system of flatworms? Answer: 1
Flatworms digestive system is called 2-way which mean the same opening is used for eat and removing waste. That's why it only has one opening. Human system is one way since we eat from the mouth and remove waste from the anus.</span>
Muscle cells contain protein filaments of actin and myosin that slide past one another, producing a contraction that changes both the length and the shape of the cell. Muscles function to produce force and motion.
Endocyrosis and exocytosis are types of bulk transport
Answer:
Water striders are able to walk on top of water due to a combination of several factors. Water striders use the high surface tension of water and long, hydrophobic legs to help them stay above water.
Water striders use this surface tension to their advantage through their highly adapted legs and distributed weight. The legs of a water strider are long and slender, allowing the weight of the water strider body to be distributed over a large surface area. The legs are strong, but have flexibility that allows the water striders to keep their weight evenly distributed and flow with the water movement. Hydrofuge hairs line the body surface of the water strider.
Answer:
A. through proteins embedded in the membrane that "recognize" specific substrates and allow their passage.
Explanation:
Some of the membrane proteins serve as transport proteins. These transport proteins can serve as channels, carriers or pumps and allow facilitated diffusion or active transport of the substances across the membrane. ion channels are transport proteins that allow specific ions to move across the membrane since the charged ions cannot cross the non-polar core of the membranes. Most of the ions channels are specific and allow only particular ions to move through them. For example, Na+ ion channels will allow only Na+ ions to move across it while the chloride ions would not able to move through it.