Explanation:
In the majority of cases, the extra copy of chromosome 21 comes from the mother in the egg.
In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm.
In the remaining cases, the error occurs after fertilization, as the embryo grows.
I think it is A because birds do help spread around the seeds hope i helped
Answer:
Mutualism
Explanation:
When the two different population species interact in such a manner that it is beneficial to each other, then this form of interaction is called mutualism.
The amount of the 30 gram-sample that will remain after 270 years is 6.61 grams
<h3>How to determine the number of half-lives </h3>
We'll begin by obtaining the number of half lives that has elapsed. This can be obtained as follow:
- Half-life (t½) = 96 years
- Time (t) = 270 years
- Number of half-lives (n) =?
n = t / t½
n = 270 / 99
n = 2.8125
<h3>How to determine the amount remaining </h3>
- Original amount (N₀) = 30 grams
- Number of half-lives (n) = 2.8125
- Amount remaining (N) =?
The amount remaing can be obtained as follow:
N = N₀ / 2^n
N = 30 / 2^2.8125
N = 6.61 grams
Learn more about half life:
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