Answer: Possession of Valves
Explanation: Veins possess valves which ensures that blood flows in only one direction. Valves helps blood to flow back to the heart against gravitational force.
Arteries don't have valves because the pressure originating from the heart is capable of causing the blood to flow in one direction.
The wood in a matchstick is made of cellulose, a polymer of glucose molecules. When you light the matchstick, heat and light are given off, indicating that an exothermic reaction is occurring.
There are two types of reactions:
1. Exothermic reactions: In these reactions, the reactants combine to form product and heat is liberated. Example, burning of fuel.
2.Endothermic reactions: In these reactions, the reactants combine to form product and heat gets absorbed from the surroundings. Example, photosynthesis in plants where the energy of the Sun gets absorbed.
<span> 2.5 million red blood cells can be destroyed every second
Hope this helps!
:D
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Answer: the earth was just starting to develop really well and well enough for life.
Explanation: atmospheric oxygen and oceanic calcium levels went up, but nobody needs to know that much facts about how earth developed, But the group called phyla started growing because of these conditions
Four haploid cells each chromosome containing 2 sister chromatids.
you are right, it's B.) 4 haploid cells