Acquired Traits vs. Inherited Traits

This section explains the difference between acquired and inherited traits in genetics.

Acquired traits are characteristics gained from the environment and are not hereditary.

Example: Dyed hair and the ability to play the piano are acquired traits.

Vocabulary: An acquired trait is a characteristic that is learned or gained from the environment and is not passed down to offspring.

Inherited traits, on the other hand, are hereditary characteristics passed down from parent to offspring through genes.

Example: Skin color and dimples are inherited traits.

Definition: An inherited trait is a characteristic that is hereditary and passed down from parent to offspring through genes.

Genes and Alleles

This section introduces the concepts of genes and alleles, which are fundamental to understanding genetics.

Definition: A gene is a factor passed down from parent to offspring that controls a trait.

Example: There are genes for dimples and pea plant height.

Alleles are different forms of the same gene.

Highlight: There are at least two alleles for every gene.

Example: For plant height, there can be a tall allele and a short allele.

Dominant and Recessive Alleles

This page explains the concept of dominant and recessive alleles in genetics.

Definition: A dominant allele is one whose trait always shows up in the organism when present, represented by a capital letter.

Example: A black fur gene in a cat is dominant, while the white fur gene is recessive.

Definition: A recessive allele is hidden whenever the dominant allele is present, represented by a lowercase letter.

Highlight: Recessive alleles show up much less frequently than dominant alleles.

Purebred and Hybrid Organisms

This section discusses the concepts of purebred and hybrid organisms in genetics.

Definition: A purebred organism is the offspring of many generations that have the same form of a trait and therefore has two identical alleles.

Example: A purebred black cat will have received two dominant black alleles from its parents.

Definition: A hybrid organism has two different alleles (one dominant allele and one recessive allele) for a trait.

Example: A kitten with both black and white fur is a hybrid.

Genotype and Phenotype

This page explains the crucial concepts of genotype and phenotype in genetics.

Definition: Genotype is an organism's genetic makeup (combination of alleles).

Highlight: Genotypes control what we look like.

Definition: Phenotype is an organism's physical appearance (visible traits).

Example: Brown hair and blue eyes are examples of phenotypes.

Homozygous and Heterozygous Genotypes

This section clarifies the difference between homozygous and heterozygous genotypes.

Definition: A homozygous genotype is the genotype of an organism with two of the same alleles.

Example: DD (homozygous dominant) and dd (homozygous recessive) are examples of homozygous genotypes.

Definition: A heterozygous genotype is the genotype of an organism with two different alleles.

Example: Tt and Dd are examples of heterozygous genotypes.

Punnett Squares and Probability

The final section introduces Punnett squares and genetic probability.

Definition: A Punnett square is a chart that shows all the possible ways alleles can combine in a genetic cross.

Example: A Punnett square can be used to calculate the probability of offspring receiving certain genes.

Definition: Probability in genetics is a number expressed as a fraction, percent, or ratio that describes how likely it is that an event will occur.

Example: In a genetic cross, the probability of offspring might be 75% tall and 25% short.

Page 9: Hybrid Organisms

This page discusses hybrid organisms and their genetic makeup.

Definition: A hybrid organism possesses two different alleles for a trait, typically one dominant and one recessive.

Example: A kitten with both black and white fur demonstrates hybrid characteristics.

Highlight: Hybrids show how different alleles can interact within an organism.

Page 10: Genotype

This page explains genotypes and their significance in genetics.

Definition: Genotype refers to an organism's genetic makeup or combination of alleles.

Example: Height inheritance is determined by the specific combination of alleles received from parents.

Highlight: Genotypes determine the potential traits an organism can express.

Page 11: Phenotype

This page covers phenotypes and their relationship to genetic expression.

Definition: Phenotype is an organism's physical appearance or visible traits.

Example: Brown hair and blue eyes are examples of phenotypes.

Highlight: Phenotypes are the observable manifestation of genotypes.