Please help me with number 9. I need to use all the words that are given and make sentences out of it.

amber has allowed scientists to study dna that has been preserved over millions of years.

the answer would be 2, if crossing over doesn’t occur 2 out of 4 of the daughter cells will have that allele.

hope this : )

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added