Passive is when the channels don't need energy to do so and active is when they need energy
Answer:
Cross overs can lead to formation of chromosome pairs that have no mutant allele.
Explanation:
Cross overs can lead to formation of chromosome pairs that have no mutant allele.
For example -
Suppose "X" is a mutant allele and "x" is a mutant free allele.
Now when two homologous chromosomes contains a single mutant allele in different parts of the chromosome are crossed the following offspring are produced
X x
X XX Xx
x Xx xx
"xx" is a mutant free genotype.
Thus, crossing over can create a single mutation-free chromosome
a glacier made of ice can erode a landscape made of rock because there can be water held within the rock that gets frozen, and because water expands when it is frozen the rock breaks apart and the glacier grinds its' way 'downhill' (down a mountain range, a good example of this is the Appalachian mountain range) and carves out a significant amount of material that is below it, as well as the materials frozen inside of the glacier. so glaciers can freeze the rocks, and then scrape away any material that is softer than rock.
Tobias drank from a contaminated water fountain
During the rock cycle igneous rock is weather into metamorphic rock