heterozygous
Heterozygous (adjective) means having two different versions of a gene at the same position on a pair of chromosomes, one inherited from each parent. Example: “Both parents are heterozygous for the sickle cell trait, so each child has a one in four chance of inheriting the disease.”
How to Use Heterozygous
Learner’s notesIn plain EnglishHaving two different versions of the same gene, one from each parent.
Technical genetics vocabulary; standard in school biology and medical reports.
Do not confuse it with heterogeneous, which is about mixtures, not genes.
Trace the full origin ↓Fill the Gap
Can you complete this real example?
Both parents are _____ for the sickle cell trait, so each child has a one in four chance of inheriting the disease.
Etymology
From Greek heteros 'different' and zygotos 'yoked together', from zygon 'yoke'.
Antonyms
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Rhymes for heterozygous
See all rhymes for heterozygous →Frequently Asked Questions
What is the difference between heterozygous and homozygous?
Heterozygous means the two copies of a gene differ, such as one brown-eye allele and one blue-eye allele. Homozygous means both copies are identical. A heterozygous individual can pass on either version to their offspring.
Can a heterozygous person show a recessive condition?
Not usually. With one working copy of the gene they are typically healthy carriers who can pass the recessive allele on. Some conditions are the exception, either because the faulty allele is dominant or because one working copy is not enough.
What does heterozygous advantage mean?
A situation where carrying two different alleles is better for survival than carrying two of either. The classic example is sickle cell trait, where carriers gain some resistance to malaria without developing sickle cell disease.