Answer:
The amount of substance present in a certain sample can be calculated through the equation,
A(t) = A(o)(0.5)^(t/h)
where At is the amount now, Ao is the original amount, t is the number of years and h is the half-life.
For a substance to at most 50% of the original amount, we get the half-life value.
At/Ao = 0.5 = 0.5^(4.5/h)
h = 4.5 billion.
Answer:
gene flow between distinct gene pools
Explanation:
In ecological studies, a hybrid zone can be described as an area in which mating occurs between organisms of two closely related species. As a result, viable offspring are produced. When reinforcement occurs, we will see that a decline in gene flow between organisms of these species will be seen. The organisms which are only closely related will be able to reproduce to produce viable offsprings. In a stable hybrid zone, continued production of hybrids will take place.
Answer:
3:1
Explanation:
Let the allele for tall plant be T; &
The allele for short plant be t
When Mendel crossed true-breeding tall pea plants(i.e TT) with true-breeding short pea plants(I.e tt); all the offspring were tall.
TT × tt
T T
t Tt Tt
t Tt Tt
we can deduce from the punnet square that the F1 offspring are all heterozygous tall plant.
Now, if the first generation (F1) tall plants are allowed to self-pollinate; we have a cross between Tt and Tt
TT × tt
T t
T TT Tt
t Tt tt
We can see phenotypically that we have 3 tall plant(TT,Tt, Tt) and 1 short plant(tt).
Therefore the ratio of phenotypes he expected in the F2 generation is (3:1)
Answer: B)typically flows from producers through a series of consumers
Explanation:
Answer: B Sputnik
Explanation: I hope this helps you
