Answer: A the chromosomes from another parent cell were introduced
Explanation: A child is created when the male sex cell joins the female cell. If the male and female sex cells had the standard number of chromosomes, as is found in body cells then the zygote (baby) would have double that number of chromosomes. The number of chromosomes would keep doubling every generation. To avoid this doubling the parent's body cells split by miosis which halves the number of chromosomes and so when the sex cells join the total number of chromosomes is the same as that found in the parent's body cells.
Answer:

Explanation:
We are asked to find how much of a 40 gram sample remains after 12 years.
Iron-55 has a half-life of 3 years. Therefore, after 12 years, 4 half-lives have been completed.
- 12 years/3 years = 4 half-lives
Every time a half-life is completed, half of the sample's mass decays. Remember we start with a 40 gram sample.
- 1 half- life: 40 g / 2 = 20 g
- 2 half-lives: 20 g / 2= 10 g
- 3 half-lives: 10 g / 2 = 5 g
- 4 half-lives: 5 g / 2 = 2.5 g
There is also a formula that can be used to solve this problem.

Where A₀ is the initial amount, t is the time, and hl is the half-life.
We know 40 grams is the inital amount, 12 years is the time, and 3 years is the halflife.




After 12 years, <u>2.5 grams </u> of Iron-55 will remain.
I believe the answer is c
The answer is A, storing urine until it is eliminated.
The bladder stores urine, allowing urination to be infrequent and controlled. The bladder is lined by layers of muscle tissue that stretch to hold urine. The normal capacity of the bladder is 400-600 mL. During urination, the bladder muscles squeeze, and two sphincters (valves) open to allow urine to flow out.