homozygous / heterozygous
homocigoto / heterocigoto
homozygous means having two identical alleles for a gene; heterozygous (also called hybrid) means having two different alleles.
Example
A pea plant that is TT or tt is homozygous; a plant that is Tt is heterozygous.
In Spanish
homocigoto / heterocigoto — homocigoto significa tener dos alelos idénticos de un gen; heterocigoto (también llamado híbrido) significa tener dos alelos distintos.
Una planta de chícharo TT o tt es homocigota; una planta Tt es heterocigota.