If the dominant allele is t and the recessive allele ("non-taster") is n, than tn and tt are the genotypes of a "taster". tn is heterozygous and tt is dominant homozygous. nn is the genotype of a "non-taster" and it is recessive homozygous.
The contractile vacuole expels excess fluid from the cell.
Answer:
In speciation, organisms evolved with the passage of time.
Explanation:
Speciation is the evolutionary process in which populations of species evolve with the passage of time to become different species from the original one. Temporal isolation and gametic isolation are two possible prezygotic barriers of the Hawaiian honeycreepers that contribute to occur speciation. The newly available niches could lead to speciation of that organisms that tolerate the Hawaiian climatic conditions when the extinction of Hawaiian honeycreepers occurs. The new organisms used the available resources such as food and space etc and increase its population.
The fossil record shows a sequence from simple bacteria to more complicated organisms through time, it is very reliable because it is physical evidence and by studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.
Basically the first part is when the Euglena starts swimming to the light direction.
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