key terms

Cards (9)

What is an allele?
A form/version of a gene.
What is a genotype? 
The alleles present, which operate at a molecular level to develop characteristics.
What is a phenotype? 
The characteristic expressed by the organism.
What is meant by dominant?
The allele that is always expressed, even when one copy is present.
What is meant by recessive?
The allele that is only expressed if two copies are present.
What is meant by homozygous? 
the alleles present are the same.
What is meant by heterozygous? 
the alleles present are different.
What is polydactyly?
Having extra fingers or toes, caused by a dominant allele.
What is cystic fibrosis?
A disorder of cell membranes, caused by a recessive allele.