Troposphere should be the answer
Answer:
Sun
Explanation:
Sun is the only star in our solar system, and planets orbit around it. Our solar system is the part of Milky way (located in one of the outer bands of the Milky way), and the Milky way is the part of the Universe (Universe is made up of billions of galaxies, and Milky way is one of those galaxies). Hence, in the given options, the Sun is the part of all of the other options given.
Testosterone is an example of a steroid. Its physiological functions include:
1. Determines the the gender of a developing embryo.
2. Development of reproductive organs and the prostrate gland in males.
3. Responsible for secondary sexual characteristics in males such as deeper pitch, increased muscle bulk, hair on the upper lip.
4. Regulates normal sperm development.
Another steroid is cholesterol. Physiological functions include:
1. Helps maintain the structure of cells and vessels improving overall health and function in the body.
2. Precursor to important sex hormones such as testosterone and estrogen.
3. Used as an insulator around nerves and is absolutely essential for brain function.
4. Precursor to Vitamin D, which supports a healthy immune and nervous system
No but they are considered protected