Answer:
8.7 million
Explanation:
About 8.7 million (give or take 1.3 million) is the new, estimated total number of species on Earth -- the most precise calculation ever offered -- with 6.5 million species on land and 2.2 million in oceans.
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.
I think it is the 3rd one because health problems at older age.
Your answer is C the objects should attract to each other due to Newton's laws.