Dictionary » H » Homozygous




(1) Of, or pertaining to an individual (or a condition in a cell or an organism) containing two copies of the same allele for a particular trait located at similar positions (loci) on paired chromosomes (see homologous chromosomes).

(2) Having two identical alleles that code for the same trait.


A ‘homozygous’ organism for a particular trait is described to possess either a pair of dominant alleles (e.g. AA) or a pair of recessive alleles (e.g. aa).

Word origin: G. ‘homo’ meaning ‘same’ + zygous, which pertains to a zygote.

Related forms: homozygosity (noun).
Related phrases: homozygous recessive, homozygous dominant.

Compare: heterozygous.
See also: allele.

Please contribute to this project, if you have more information about this term feel free to edit this page

Results from our forum

Genetics Pedigree Help Required

... recessive pattern? Can you not have, if it is autosomal dominant, each affected individual as heterozygous and each unaffected individual homozygous recessive; and if it is autosomal recessive you reverse it so that each affected individual is homozygous recessive and each unaffected individual ...

See entire post
by TheBell
Fri Mar 21, 2014 8:49 pm
Forum: Genetics
Topic: Genetics Pedigree Help Required
Replies: 0
Views: 1672

Need an help about Drosophila genetics

... have 4 chromosomes: 2 and 3 are useful for genetics. For each chromosomes there are two copies just like in humans: 2nd chromosome: UAS-UPRT is homozygous 3rd Chromosome: One chromosomes carries Repo. The other carries a marker TM6 which gives flies short bristles. You are starting from: 2nd ...

See entire post
by golgicik
Wed Oct 30, 2013 8:46 pm
Forum: Genetics
Topic: Need an help about Drosophila genetics
Replies: 5
Views: 2680

Re: I need help with Punnett Square

The fly been double homozygous the wild type most likely would have had a ratio of around 3:1 for the offspring. No. All of the offspring would have been wild type. The rest of your answer is correct. F0: cross female (Female: BW) ...

See entire post
by Cat
Sat Oct 05, 2013 1:11 pm
Forum: Genetics
Topic: I need help with Punnett Square
Replies: 1
Views: 3161

I need help with Punnett Square

... Female: + 4982 0.4980 1.000 Male: + 5023 0.5020 1.008 Total 10005 then I Designed a male fly with brown eye (BW) color AND ebony body (E) color (homozygous recessive for both traits), then test cross this fly with an F1 wild-type female fly from the above cross. Results of Cross #2 Parents (Female: ...

See entire post
by Yokie83
Sun Sep 29, 2013 9:21 pm
Forum: Genetics
Topic: I need help with Punnett Square
Replies: 1
Views: 3161

unbalanced gender ratios of offspring

... females reduces genetic diversity in comparison to several males producing with several females. If we take a genetic example: One male - TT (homozygous dominant) Breeding with several females lets say they're all Tt. Production: TT x Tt - 2 possibilities However an array of males TT, Tt, ...

See entire post
by wildfunguy
Sat Sep 07, 2013 10:47 pm
Forum: Human Biology
Topic: unbalanced gender ratios of offspring
Replies: 6
Views: 4443
View all matching forum results

This page was last modified 00:21, 13 July 2008. This page has been accessed 282,260 times. 
What links here | Related changes | Permanent link