A space probe discovers a planet inhabited by creatures who reproduce with the same hereditary patterns as those in humans. Three phenotypic characters are height (T = tall, t = dwarf), hearing appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures were not "intelligent" Earth scientists were able to do some controlled breeding experiment.s.

1. If a dihybrid cross was performed between a homozygous dominant alien and a homozygous recessive alien testing only for height and head appendages what would be the genotype of the parent generation? What types of gametes would the parent generation make and their proportions? Indicate the genotypes of F1 with a description of the phenotype.
2. What possible gametes could the F1 generation make and in what proportions? what is the F2 phenotype ratio of the cross described in question 1? describe the different phenotypes.

1. To determine the genotype of the parent generation, we can look at the information provided about the dihybrid cross testing for height (T = tall, t = dwarf) and head appendages (A = antennae, a = no antennae).

In this case, a homozygous dominant alien (TTAA) and a homozygous recessive alien (ttaa) are crossed. This means the first parent is dominant for both traits (Tall with antennae), while the second parent is recessive for both traits (Dwarf with no antennae).

To determine the possible gametes the parent generation can produce, we can consider the law of segregation. According to this principle, each parent will randomly pass on one allele for each trait to their offspring.

For the first parent (TTAA), it will produce gametes with the combinations of alleles for each trait: TA. This is because it only has one allele for each trait, so it can only pass on that particular allele.

For the second parent (ttaa), it will produce gametes with the combinations of alleles for each trait: ta. Similar to the first parent, it can only pass on one allele for each trait.

The proportions of the gametes produced will be equal, as the parents are homozygous for both traits. So, each parent will produce 50% TA and 50% ta gametes.

Now, let's look at the genotypes of the F1 generation. When the gametes from the parent generation combine, they will form four possible combinations: TATA, TAta, tATA, and tAta.

The F1 generation's genotype is TtAa, which means they are heterozygous for both height and head appendages. The phenotype of the F1 generation would be tall with antennae, as the dominant alleles (T and A) determine these traits.

2. Moving on to the F1 generation, let's determine the possible gametes they can produce and their proportions.

Since the F1 generation is heterozygous for both height (Tt) and head appendages (Aa), they will produce gametes by independently segregating the alleles for each trait.

For height, the possible gametes are T and t, each with an equal proportion of 50% due to the law of segregation.

For head appendages, the possible gametes are A and a, each with an equal proportion of 50% again.

When we consider both traits simultaneously, there are four possible combinations of gametes that the F1 generation can produce: TA, Ta, tA, and ta. Each combination has an equal proportion of 25%.

Now, let's move on to the F2 generation phenotype ratio. To determine this, we need to consider the possible combinations of alleles from the F1 generation gametes.

When we combine the gametes TA, Ta, tA, and ta, we get the following genotypes in the F2 generation: TTAa (tall with antennae), TTaa (tall with no antennae), TtAa (tall with antennae), Ttaa (tall with no antennae), ttAa (dwarf with antennae), ttaa (dwarf with no antennae).

The phenotypes of the F2 generation can be described as follows:
- 2 tall with antennae
- 1 tall with no antennae
- 1 dwarf with antennae
- 2 dwarf with no antennae

Therefore, the F2 phenotype ratio would be 2:1:1:2, representing the different combinations of height and head appendages in the offspring.