Compared to arteries, valves have no pulse, have thin walls and have valves that prevent backflow of the blood. The pressure in the veins is less than that of the arteries, hence, there is no pulse. They are nearer to the surface of the skin. It also connects arteries and capillaries which transport blood all throughout the circulatory system.
Diatoms contain chloroplasts that have four membranes. These four membranes are evidence of secondary endosymbiosis (Option c).
<h3>What is secondary endosymbiosis?</h3>
Secondary endosymbiosis is a hypothesis used to explain why diatom chloroplasts have four membranes.
According to this hypothesis, diatoms received different genes from distinct photosynthetic and non-photosynthetic ancestors.
The acquisition of genes of different ancestors led to diatoms having chloroplasts with four membranes.
Learn more about the endosymbiosis hypothesis here:
brainly.com/question/2957447
Answer: Neurone
Explanation:
Neurone is also known as nerve cell. It is the basic unit of the nervous system, and helps to transmits/ conducts nerve impulses from the brain to the body or vice versa.
Carbohydrates,lipids,proteins,vitamins,,water, minerals
It is extremely useful for geologists, because most specimens of a given mineral are very close to the same hardness. ... So, we can conclude that not all the rocks are hard, and the hardness of rocks depends on how the atoms of the rock's minerals are bound to each other and how they are arranged.
