Answer:

Single-celled organisms are in constant contact with their environments, obtaining nutrients and oxygen directly across the cell surface. The same holds true for small and simple plants and animals, such as algae, bryophytes, sponges, cnidarians, and flatworms. Larger and more complex plants and animals require methods for transporting materials to and from cells far removed from the external environment. These organisms have evolved transport systems.

Single-celled organisms are in constant contact with their environments, obtaining nutrients and oxygen directly across the cell surface. The same holds true for small and simple plants and animals, such as algae, bryophytes, sponges, cnidarians, and flatworms. Larger and more complex plants and animals require methods for transporting materials to and from cells far removed from the external environment. These organisms have evolved transport

Single-celled organisms are in constant contact with their environments, obtaining nutrients and oxygen directly across the cell surface. The same holds true for small and simple plants and animals, such as algae, bryophytes, sponges, cnidarians, and flatworms. Larger and more complex plants and animals require methods for transporting materials to and from cells far removed from the external environment. These organisms have evolved transport systems.

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Single-celled organisms are in constant contact with their environments, obtaining nutrients and oxygen directly across the cell surface. The same holds true for small and simple plants and animals, such as algae, bryophytes, sponges, cnidarians, and flatworms. Larger and more complex plants and animals require methods for transporting materials to and from cells far removed from the external environment. These organisms have evolved transport systems.