Answer:
Design more studies testing the effect of duration and intensity of exercise on cholesterol levels in different age groups.
Explanation:
<span>More than 50</span>. There are more than 7000 chemicals in cigarette smoke, 250 of which are known to be detrimental to health and 69 chemicals are carcinogenic (can cause cancer). Some of the carcinogenic chemicals in cigarette smoke are: Arsenic, Cadmium, Chromium, Formaldehyde and Nickel.
The nuclear envelope is perforated with pores to allow it to move in and out of the nucleus.
Every cell in the body has a nucleus, except for mature erythrocytes (red blood cells). While some cells contain more than one nucleus such as skeletal muscle and some other cells contain several nuclei.
The nuclear envelope surrounds the nucleus. i. e. largest organelle of the cell. It has a similar structure to that of
the plasma membrane. But the nuclear envelope contains tiny pores that allow a few substances to pass between it and outside the cytoplasm, i.e. the cell contents excluding the nucleus.
Therefore, the nuclear envelope is perforated with pores to allow it to move in and out of the nucleus.
To know more about the nucleus, refer to the below link:
brainly.com/question/2437355
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I would say that two products of the earth are coal and petroleum and when they are burned say in a car or a power generating facility they can be converted to fossil fuels.The burning of these fossil fuels are causing too much greenhouse gases and making the earth's temperature rise and resulting in more extreme weather so fossil fuels need to be phased out so the earth will remain inhabitable for humans.
