Answer:the valves prevents the backward flow of blood
Explanation:
Answer: Option D.
Crystalline and rigid.
Explanation:
When liquid freezes to ice, it becomes solid and this is crystalline and rigid because a solids for crystals which means solid atoms, molecules or ions are orderly arranged in structures which form of crystal lattice in all sides. The structure of solid becomes rigid , it does not take the container shape like liquid and it does not expand also like liquid. it volumes reduces.
Answer: Kingdom Animalia (Multicellular Heterotrophs)
Explanation:
Heterotrophs (animals) cannot make their own food like the green plant (autotrophic mode of nutrition). So they have to search for foods by moving about. They can feed in plants, other organisms /animals or feed on dead materials.
Animals are multicellular (with many specialised cells). For example the cell in our nose are meant to respond to smell while that of the eyes are specialised for light capture. Our muscle cells focused on movement. Unlike the plants, animals lack cell walls.
Answer:
individuals of the same species that live in the same area
Explanation:
The definition of a weed is a plant growing where it is not wanted. It can also include plants that were not intentionally sown in a specific location or plants that are more competitive or interfere with the activity of people.
