<span>Alleles are usually represented by three different methods using two alphabets; when the two alphabets are small letters, it means that both alleles are recessive; when the two alphabets are capital letters, it means that both alleles are dominant and when one of the letter is capitalized and the other a lower case, it means that one of the allele is dominant while the other is recessive. Genotype CC means that the two alleles for curly hair are dominant.</span><span />
Advantage: Dichotomous keys are very useful because they allow non-expert users to identify organisms by directing them to look at the known, important organisms. Disadvantage: Disadvantage of dichotomous keys is that if a single wrong decision is made at any juncture, a wrong identification will result. Sometimes it becomes obvious that an error has been made, and you can retrace your steps until you get back on the right track, but this is not always the case
The last three are correct
<span>Unconformities occur when younger rock is placed on top of older rock
hope this helps
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