Why Organisms Look The Way They Do - Flashcard 2 Review

Front

What is genetic variation and why is it important in a population?

Back

Genetic variation refers to the differences in DNA among individuals within a population. It is important because it allows for adaptability and evolution, enabling populations to survive changes in the environment.

Front

What does it mean for an allele to be recessive?

Back

A recessive allele is one that does not manifest in the phenotype unless two copies are present (homozygous). It is overshadowed by a dominant allele when both are present.

Front

Define genotype and phenotype. How are they related?

Back

Genotype is the genetic makeup of an organism (the alleles it carries), while phenotype is the observable characteristics or traits. The phenotype is influenced by the genotype and environmental factors.

Front

What is the significance of dominant and recessive traits in inheritance?

Back

Dominant traits are expressed in the phenotype even if only one copy of the allele is present, while recessive traits require two copies to be expressed. This affects how traits are passed from parents to offspring.

Front

How many alleles does a child inherit from each parent for a given trait?

Back

A child inherits one allele from each parent for each trait, resulting in two alleles for that trait.

Front

What is the difference between homozygous and heterozygous genotypes?

Back

Homozygous genotypes have two identical alleles for a trait (e.g., AA or aa), while heterozygous genotypes have two different alleles (e.g., Aa).

Front

What is a Punnett square and how is it used in genetics?

Back

A Punnett square is a diagram used to predict the genetic outcomes of a cross between two organisms. It shows the possible combinations of alleles from the parents.

Front

Explain the concept of alleles. How do they contribute to genetic diversity?

Back

Alleles are different versions of a gene that can exist at a specific locus on a chromosome. They contribute to genetic diversity by providing variations in traits among individuals.

Front

What does it mean for a trait to be dominant?

Back

A dominant trait is one that is expressed in the phenotype even when only one copy of the dominant allele is present. It masks the effect of a recessive allele.

Front

How can environmental factors influence phenotype?

Back

Environmental factors such as nutrition, temperature, and exposure to toxins can affect the expression of genes, leading to variations in phenotype even among individuals with the same genotype.