The principle of probability allows us to predict the possible combinations of phenotypes in a genetic cross by using a diagram called Punnett squares. This diagram represents alleles and gives us the genetic variations formed during a cross. For example, a flower has one dominant allele for a blue color, which is represented by capital T, and one recessive allele for a pink color, which is represented by small t. When this flower is crossed with another flowering plant with the same type of alleles, which is Tt, the combinations produced for their offspring includes TT, Tt, tT, and tt.

The principle of probability allows us to predict the possible combinations of phenotypes in a genetic cross by using a diagram called Punnett squares.

A Punnett square diagram represents the alleles present in an organism and gives us the genetic variations formed during a cross. To show the probability of an offspring having a particular genotype, this diagram is used. It lists all the possible combinations of the alleles from the two parents in the four boxes. Here is an example:

Interpretation:

B = dominant allele for brown eyes
b = recessive allele for blue eyes

Genotype of parents: bb and Bb

Possible genotype of offspring:
bB, bB, bb, and bb

Considering that one parent has two recessive alleles for blue eyes and the other parent has one dominant allele for brown eyes and one recessive allele for blue eyes, the possible genotype combinations are bB, bB, bb, and bb. This means that the probability of them having an offspring with brown eyes is 50% and the probability of the having an offspring with blue eyes is also 50%.

A Punnett square diagram represents the alleles present in an organism and gives us the genetic variations formed during a cross. To show the probability of an offspring having a particular genotype, this diagram is used. It lists all the possible combinations of the alleles from the two parents in the four boxes.

**Probability** is generally defined as the likelihood that a particular event would occur. Let us take a coin flip as an example, which has two possible outcomes, either heads or tails.

Since a coin flip only has two possible outcomes, the likelihood that one of these outcomes occur is 1 chance in 2. In other words, the probability of each outcome would be 50%.

In the context of genetics, probability is used to predict the outcome of genetic crosses. This is due to the fact that the segregation of alleles is completely random, similar to a coin flip.

The **genotype** of an organism generally refers to the collection of genetic information or its genetic makeup. The genotype represents the information encoded by the DNA of an organism.

On the other hand, the **phenotype** of an organism generally refers to the observable traits exhibited by the organism according to the genetic information that is encoded by its genotype.

Additionally, the phenotype of an organism does not always reflect its genotype. In some cases, part of the genotype is not expressed in the organism, thus the phenotype would not occur.

T = dominant allele for tallness
t = recessive allele for shortness

If a homozygous plant with a genotype of tt is crossed to a heterozygous plant with a genotype of Tt, the combination produced are Tt, Tt, tt, and tt.

Possible genotype of offspring:
a. Tt = tall
b. Tt = tall
c. tt = short
d. tt = short

Therefore, there is 50% probability that a tall plant will be produced in the next generation.

There is 50% probability that a tall plant will be produced in the next generation if a homozygous short plant is crossed with a heterozygous plant.