Mendel and the Basics of Inheritance
The foundations of inheritance
Who was Mendel?
Gregor Mendel studied pea plants and noticed clear inheritance patterns. His work helped establish the basic rules of genetics.
Dominant and recessive
In simple Mendelian inheritance, one allele may be dominant and another recessive. A dominant allele can determine the phenotype even when only one copy is present, while a recessive allele usually appears only when two copies are present.
Important simplification
Not all traits follow simple dominant-recessive rules. Many traits are more complex.
Mendelian terms
| Term | Meaning |
|---|---|
| Dominant | An allele that can show its effect with one copy |
| Recessive | An allele that usually shows only with two copies |
| Homozygous | Having two of the same allele |
| Heterozygous | Having two different alleles |
What did Mendel study?
Mendel's famous experiments were done with pea plants.
Correct answer: Pea plants
What does homozygous mean?
Homozygous means both copies of a gene are the same version.
Correct answer: Having two of the same allele
A recessive trait usually appears when an organism has:
In simple inheritance, recessive traits typically require two recessive copies.
Correct answer: Two recessive alleles
Why is Mendel's work still important?
Mendel's experiments explained predictable inheritance patterns that still form the basis of genetics.
Correct answer: It revealed basic rules of inheritance