Key Concepts in Genetics

Questions and Answers

What does it mean if an organism is homozygous?

Two different alleles for a trait

The offspring of many generations with the same traits

Two identical alleles for a trait (correct)

An organism's physical appearance

What does it mean if an organism is heterozygous?

Two different alleles for a trait (correct)

The likelihood that a particular event will occur

A gene that has more than two alleles

Two identical alleles for a trait

What is phenotype?

An organism's physical appearance or visible traits.

What is genotype?

An organism's genetic makeup or allele combinations. Signup and view all the answers

What is a Punnett square?

A chart that shows all the possible combinations of alleles that can result from a genetic cross. Signup and view all the answers

What is the definition of probability in genetics?

The likelihood that a particular event will occur. Signup and view all the answers

What is a purebred?

The offspring of many generations that have the same traits. Signup and view all the answers

What is incomplete dominance?

A blending of both parental traits Signup and view all the answers

What is codominance?

Both alleles are fully expressed Signup and view all the answers

What are multiple alleles?

A gene that has more than two alleles. Signup and view all the answers

What is a polygenic trait?

A trait controlled by two or more genes. Signup and view all the answers

What is genetics?

The scientific study of heredity. Signup and view all the answers

Who is Gregor Mendel?

Augustinian monk and botanist, recognized as the founder of genetics. Signup and view all the answers

What is self-fertilization?

Fusion of sperm and egg produced by the same organism Signup and view all the answers

What does hybrid refer to?

The offspring of different trait parents Signup and view all the answers

What is the P generation?

Parental generation, the first two individuals that mate in a genetic cross. Signup and view all the answers

What is the F1 generation?

The first generation of offspring obtained from an experimental cross. Signup and view all the answers

What is the F2 generation?

Offspring resulting from interbreeding of the hybrid F1 generation. Signup and view all the answers

What are alleles?

Different forms of a gene Signup and view all the answers

What does the chromosome theory of inheritance state?

Chromosomes are the genetic material passed from generation to generation Signup and view all the answers

How many chromosomes are in a human sex cell?

23 Signup and view all the answers

How many chromosomes are in a human body cell?

46 Signup and view all the answers

What is meiosis?

The cell division process through which sex cells form. Signup and view all the answers

Study Notes

Key Genetics Concepts

Homozygous: Organism with two identical alleles for a trait (e.g., AA or aa).
Heterozygous: Organism with two different alleles for a trait (e.g., Aa).
Phenotype: Observable physical traits of an organism, influenced by genotype.
Genotype: Genetic makeup or combination of alleles in an organism (e.g., PP, Pp, or pp).
Punnett Square: Tool used to predict potential allele combinations from genetic crosses.

Inheritance Patterns

Incomplete Dominance: A genetic inheritance pattern where neither allele is completely dominant, resulting in a blended phenotype (e.g., red and white flowers producing pink ones).
Codominance: Both alleles are expressed equally in the phenotype (e.g., black and white feathers appearing together in offspring).
Multiple Alleles: Genes with more than two allele forms affecting traits (e.g., ABO blood types).
Polygenic Traits: Traits controlled by two or more genes, contributing to a range of phenotypes (e.g., skin color).

Genetic Terminology

Purebred: Offspring derived from many generations with consistent traits.
Heritage: The process of passing traits from parents to offspring.
Alleles: Different forms of a gene located at the same position on chromosomes, contributing to variations in traits.
Recessive Allele: An allele that is masked by the presence of a dominant allele; requires two copies (e.g., "aa") to be expressed.
Dominant Allele: An allele that expresses its trait in the presence of another allele (only one copy needed).

Mendelian Genetics

Gregor Mendel: Known as the father of genetics; his pea plant experiments established foundational principles of inheritance.
Generations:
- P Generation: The parental generation in a genetic cross.
- F1 Generation: The first generation of offspring from a genetic cross.
- F2 Generation: Offspring resulting from the interbreeding of F1 generation.

Chromosomes and Cells

Chromosomes: Structures containing genes, present in a organism's cells; humans have 46 chromosomes in body cells and 23 in sex cells.
Meiosis: A specialized type of cell division leading to the formation of sex cells, producing cells with half the chromosome number.

Probability in Genetics

Probability: Measures the likelihood of a specific genetic outcome; can be predicted using Punnett squares to evaluate potential genotypes and phenotypes in offspring.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore essential genetics concepts including homozygous and heterozygous traits, phenotype vs genotype distinctions, and useful tools like the Punnett Square. Understand various inheritance patterns such as incomplete dominance, codominance, and the role of multiple alleles in genetic diversity.