Động vật nào sau đây máu đu nuôi cơ thể không pha trộn giữa máu giàu o2 và máu giàu co2

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?

Using meiosis, the sporophyte produces spores that are .

The sea slug that considered to be a photosyntheesizing animal