Answer:
The answer is below
Explanation:
The half life of a substance is the time required by that substance to reduce to half of its initial value. The half life is calculated using the formula:

Given that t = 87 years, half life = 29 years, therefore the quantity of strontium-90 left is:

That is one-eight of Strontium 90 would be left after 87 years
Answer:
There are many receptors for thyroxine on different target cells (tissues), so its effect can be huge
Explanation:
Target cell for a certain hormone is a cell that have hormone receptor specific for that hormone. There are two main types of receptors on target cell:
- cell membrane receptors (also called trans membrane receptors)-usually for peptide hormones, such as insulin
- intracellular receptors (also called nuclear receptors)-usually for steroid hormones, such as testosterone.
Hormone binding to the receptor leads to the signal cascade within the cell, which results in cell response.
Receptors for thyroid hormones are nuclear receptors.
<u>Function: -</u>
The advancement of the central nervous system, the growth and operation of the reproductive organs, and also the metabolism and blood sugar level, are all regulated by the endocrine system, which is made up of all the various hormones produced by the body from conception and via adulthood and into old age.
Metabolism- The alterations in an organism's or a cell's chemistry. These modifications generate the ingredients and energy that cells and organisms require to develop, procreate, and maintain health. Anabolism and catabolism are components of metabolism.
Hormones- Chemicals called hormones function in the body as messenger molecules. They are created in one area of the body and then go to other areas where they assist regulate how cells and organs function.
To know more about the Endocrine System, click on the below link,
brainly.com/question/8107696
#SPJ4
The layers above would be not as old and the layers below would be the older layers.
Large old-growth dominant forest trees, such as the redwoods, are part of a climax community (<span>final and permanent stage of vegetation)</span>. Such trees develop in a biome. These trees are also refers to a<span>n </span>old-growth forest<span> — also termed primary </span>forest<span>, virgin </span>forest<span>, primeval </span>forest<span>, late seral </span>forest<span>, </span>