What important event in animal evolution marks the beginning of the Cambrian period?

Biology

1 answer:

Alenkinab [10]3 years ago

3 0

The appearance of fossils would the the answer.

Although there has been some scientific debate about what fossil strata should mark the beginning of this period, the "International Geological Congress" determined that the Cambrian period was approximately 543 million years ago of which the first appearance in the fossil record of worms that made horizontal burrows was discovered.

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A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in thumb. to travel from the arter

ruslelena [56]

<h2>Answer is option "b"</h2>

Explanation:

Our body contains miles of arteries and arterioles, yet these structures are nothing more than the vascular highways that provide a pathway for the blood. It's only when our blood reaches the tiny capillaries that nutrients and wastes can be exchanged. Capillaries are microscopic blood vessels that connect the arterioles with the venules. We'll discuss venules later in the lesson.
Capillaries are grouped together in capillary beds, which are simply a network of capillaries. Capillary beds are too small to see, but if you could see them, they would look like endless alleyways leading to virtually every tissue in our body. The rate of blood flow within a capillary bed is slow because there are so many different alleyways through which blood can travel. This slow speed limit, along with the very thin walls of the capillaries, means that capillary beds are an ideal place for the exchange of gases, nutrients, hormones, and wastes between the blood and tissue cells.
Hence, the right answer is option b "two capillary beds".

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3 years ago

Compare the lymphatic system with the cardiovascular system

frosja888 [35]

<span>The circulatory system is the combination of the lymphatic system and the cardiovascular system. It comprises of the heart, blood vessels and blood as well as lymph, lymph nodes, and lymphatic vessels. It controls the whole transportation activity in the body.</span>

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3 years ago

The question is marked with red color. Please help me

Alexus [3.1K]

Answer:

Deserts

Explanation:

Short for desertification

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"Explain if a person were to consume an apple where would digestion begin. Then explain in detail how the apple would begin to b

adelina 88 [10]

Answer:

The process will behang in mouth. After that it will go through esophegus. Then it will go to small intenstine. Before going to large intenstine they will take out the needed chemicla substances and then only they will go to large intenstine.

Explanation:

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3 years ago

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zimovet [89]

200,000 is the population density.

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3 years ago