T pollen grain fertilizes an egg cell while a second fuses with two polar nuclei to produce a triploid body that gives rise to the endosperm.
When we inhale, we take in oxygen, and give out carbon dioxide when we exhale. The carbon dioxide we breathe out/exhales enters the atmosphere.
Answer:
many alveoli are present in the lungs with a shape that further increases surface area. Thin walls - alveolar walls are one cell thick providing gases with a short diffusion distance. Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface.
Explanation:
Answer:
hope this helps
Explanation:
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