Question

Fill in the blanks to correctly complete the sentence: The genotype of both parent plants is , which means that both parents will be

Short answer

The genotype of both parent plants is heterozygous (Aa), which means that both parents will be carrying one dominant allele (A) and one recessive allele (a) for the trait.

Step-by-step solution

Fill in the blanks with a genotype

Given that we want to talk about the genotype of both parent plants, we can choose a genotype for them. In this case, let's choose heterozygous (Aa) as the genotype. The sentence now becomes: The genotype of both parent plants is heterozygous (Aa), which means that both parents will be ______.

Explain the meaning of the genotype

Now that we have established their genotype as heterozygous (Aa), we need to explain what it means for both parents. In this case, it means that each parent has one dominant allele (A) and one recessive allele (a) for this particular trait. The completed sentence is: The genotype of both parent plants is heterozygous (Aa), which means that both parents will be carrying one dominant allele (A) and one recessive allele (a) for the trait.

Key concepts

Heterozygous Genotype

The term 'heterozygous' is vital in genetics and refers to the makeup of a particular gene within an organism. When an individual is heterozygous for a gene, it means that they have two different alleles at a specific locus (position) on their chromosomes. One of these alleles comes from one parent, and the other comes from the second parent.

In the case of plants, as mentioned in the exercise, a heterozygous genotype like Aa signifies that one allele is dominant (represented by the uppercase letter 'A') and one allele is recessive (denoted by the lowercase letter 'a'). This combination results in a unique interaction where the dominant allele masks the expression of the recessive allele, leading to the dominant trait being exhibited.

Genetic variations like heterozygous genotypes are essential for diversity in a population. They ensure that offspring have a combination of traits from both parents, which can contribute to the adaptability and survival of species in changing environments.

Dominant Allele

In genetics, an 'allele' refers to one of two or more versions of a gene. If we consider a pair of alleles that influence a particular trait, the 'dominant allele' is the one that determines the phenotype of an organism. Phenotype is the set of observable characteristics, such as eye color, leaf shape, or flower color in plants.

The dominant allele is typically represented by an uppercase letter, like 'A' in our exercise example. Even when paired with a recessive allele (a), the dominant allele's trait will be visibly expressed. Therefore, if a plant has the genotype Aa, it will display the characteristics associated with the dominant 'A' allele.

Understanding dominant alleles is crucial for predicting the outcome of genetic crosses. For instance, in a cross between two heterozygous parents (Aa x Aa), the dominant trait associated with 'A' will appear in the majority of the offspring, following Mendelian inheritance patterns.

Recessive Allele

Conversely to the dominant allele, the 'recessive allele' is the version of a gene that is overshadowed when a dominant allele is present. It is represented by a lowercase letter, such as 'a' in our exercise. The recessive allele's trait will only be expressed phenotypically if an individual has two copies of the recessive allele (aa), meaning the individual is homozygous recessive.

In the context of our plant example, when parent plants are heterozygous (Aa), the recessive allele 'a' does not manifest as a trait because of the presence of the dominant 'A' allele. However, the recessive allele can still be passed on to the offspring. When two heterozygous plants mate, there is a 25% chance for an offspring to inherit two recessive alleles, resulting in the exhibition of the recessive trait.

Recessive alleles play a significant role in genetics, especially in understanding hereditary conditions and traits. They may not always be apparent in an organism's phenotype, but they can emerge in future generations, adding to the genetic diversity and complexity of living organisms.