Heredity Quiz

Bio science Honors 9

Describe the work of Gregor Mendel

conducted experiments with pea plants in the 1800s, discovering the fundamental laws of inheritance

Who was Gregor Mendel and what did he study?

an Austrian monk and scientist often called the "father of modern genetics" for discovering the fundamental laws of inheritance

What was the outcome (describe the genotype and phenotype of the F1 offspring) of the parental (P) crosses in Mendel’s experiment? 

• Genotype: All F1 offspring were heterozygous (e.g., Pp or Tt). They each inherited one dominant allele from one parent and one recessive allele from the other.

• Phenotype: All F1 offspring exhibited the dominant trait (e.g., all purple flowers or all tall stems). The recessive trait "disappeared" in this generation because it was masked by the dominant allele.

What was the outcome (describe the genotype and phenotype of the F2 offspring) of the First Filial (F1) crosses in Mendel’s experiment? 

a predictable reappearance of recessive traits, resulting in a 3:1 phenotypic ratio (dominant:recessive), such as 3 round : 1 wrinkled, and a 1:2:1 genotypic ratio (1 homozygous dominant : 2 heterozygous : 1 homozygous recessive).

Explain the difference between dominant and recessive traits. 

If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.

Explain the difference between homozygous and heterozygous. 

Homozygous means having two identical alleles (gene versions) for a trait (e.g., RR or rr), inheriting the same version from each parent, while heterozygous means having two different alleles for a trait (e.g., Rr), inheriting a different version from each parent

Explain the difference between genotype and phenotype. 

Genotype refers to an organism's internal genetic makeup (DNA) inherited from parents, while phenotype represents the observable physical traits or behaviors resulting from the expression of those genes, heavily influenced by environmental factors. Genotypes remain stable, whereas phenotypes can change due to lifestyle, diet, or climate.

What is probability?

Mathmaticly likely an event is to occur,

Know how to complete a Punnett square to predict the genotype/phenotype of offspring.  

crossing the alleles of each parent to determine all of the possible genotypes for their offspring

Be able to calculate the percentage or ratio of the Punnett square results.  

dividing the number of squares with a specific genotype or phenotype by the total number of boxes (usually 4) and multiplying by 100 for a percentage

Be able to identify homozygous and heterozygous alleles.

checking if a pair of genes is identical or different, using letter representations (genotypes) like AA, Aa, or aa.

Be able to read a pedigree chart