Genetics and inheritance

Using the base pair rule, Adenine goes with ___ and Guanine goes with ___

• Cytosine, thymine

• Adenine, guanine

• Thymine, cytosine

• Guanine, adenine

Sketch out what DNA is shaped like:

An allele is a:

• Gene

• Form or variation of a gene

• A chromosome

• None of these

Answer explanation

Remember, the gene in general is something like eye color, but the alleles are the variations of that gene. So the alleles in this case would be blue eyes or brown eyes

A phenotype is:

• The physical expression of a gene

• The genetic makeup of the gene

• Not visible

• All of these

A phenotype is a physical expression, where the genotype is:

• Is another term for chromosomes

• Is visible for us to see

• Also the physical expression

• The genetic makeup or allele combinations

Explain the connection between genotype and phenotype:

Answer explanation

Genotype is the allele combinations, which end up coding for one phenotype or the other to show up. Which one shows up based on dominance and recessiveness

When you inherit two alleles (one from each parent), the combination can either be homozygous OR heterozygous, which means:

• Homozygous is either two big or two little alleles (the same)

• Heterozygous is a combo of one big and one small

• Homozygous = Hh

• Heterozygous = hh

Heterozygous is a mix of two alleles, so something like Aa. What determines which of these alleles is going to actually show up in the phenotype?

• The recessive little allele will show up

• The dominant allele covers the recessive, so the dominant will show up

• The dominant will show up only if there is two big A's

• It will be a mix of dominant and recessive

Purple flower pedals are dominant over yellow flower pedals. Two yellow flowers are bred together. Their offspring will be:

• Purple

• Yellow

• A mix

• You can't tell from this information alone

Purple flower pedals are dominant over yellow flower pedals. One purple and one yellow flower are bred together. Their offspring will be:

• Purple

• Yellow

• A mix

• You can't tell from this information alone

Answer explanation

Remember, for the dominant trait, there are TWO genotype possibilities: AA or Aa. If the purple flower here was heterozygous (Aa), there is a chance that the offspring will get a small "a" from this flower, and will definitely get a small "a" from the other, resulting in a yellow flower.