Most of the middle layer in the heart is composed of cardiac muscle cells
Protozoa are single-celled eukaryotes that share some traits with animals. Like animals, they can move, and they are heterotrophs. That means they eat things outside of themselves instead of producing their own food
Abiotic factors include sunlight, temperature, moisture, wind or water currents, soil type, and nutrient availability. Ocean ecosystems are impacted by abiotic factors in ways that may be different from terrestrial ecosystems.
It's depends on the size of molecule. big ones cannot pass the membrane while smaller molecules can.
