Principles of Genetics - Mendelian Inheritance

Flashcards based on Lecture 8 of GENE20020 covering Mendelian inheritance, principles of genetics, and related terminology.

What is the blending hypothesis in the context of genetics?

The blending hypothesis proposes that genetic material from two parents blends together in offspring, similar to mixing red and white paint to make pink.

Who is known as the father of genetics?

Gregor Mendel is known as the father of genetics for his experiments with garden peas that established the basic principles of heredity.

What is a monohybrid cross?

A monohybrid cross is an experiment that examines the inheritance of a single characteristic by crossing two parents with distinctly different traits.

What does the Law of Segregation state?

The Law of Segregation states that during gamete formation, alleles for each gene segregate from each other, so each gamete carries only one allele for each gene.

What is the phenotypic ratio observed in a monohybrid cross?

The phenotypic ratio observed in a monohybrid cross is typically 3:1.

What are alleles?

Alleles are one of two or more alternative forms of a gene.

Define genotype.

Genotype is the set of alleles possessed by an individual organism.

What is the Law of Independent Assortment?

The Law of Independent Assortment states that when two or more traits are observed, they can assort independently during gamete formation.

What does it mean for an organism to be a heterozygote?

A heterozygote is an individual organism possessing two different alleles at a locus.

What were Mendel's findings regarding dominant and recessive traits?

Mendel found that some alleles are dominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant trait.

What is the expected genotypic ratio of the offspring from a monohybrid cross of two heterozygous parents (Aa x Aa)?

The expected genotypic ratio is 1:2:1 (1 AA : 2 Aa : 1 aa).

What characterizes a dihybrid cross?

A dihybrid cross examines the inheritance of two traits at the same time.

What is the phenotypic ratio for a dihybrid cross?

The phenotypic ratio for a dihybrid cross is typically 9:3:3:1.

What does it mean for a trait to be dominant?

A dominant trait is a characteristic that is expressed phenotypically in an individual with at least one dominant allele.

What is a Punnett square used for?

A Punnett square is a tool used to predict the expected outcomes of genetic crosses.

What potential limitations does Mendel's work on ratios have?

Ratios are approximate and may vary, especially with low numbers, but become more accurate with larger population sizes.