Sex Determination | Drosophila, Birds & Human | Biology Grade 11 | Urdu Hindi English 2025 скачать в хорошем качестве

Sex Determination | Drosophila, Birds & Human | Biology Grade 11 | Urdu Hindi English 2025

sex determination: Sex Determination in Drosophila 1. *X-Y System*: Drosophila has an X-Y sex determination system, where males have XY chromosomes and females have XX chromosomes. 2. *X-Chromosome Dosage*: The number of X-chromosomes determines the sex of the fly. Males have one X-chromosome, while females have two. 3. *Sex-Lethal Gene*: The sex-lethal (Sxl) gene plays a crucial role in sex determination. It is activated in females and repressed in males. Sex Determination in Grasshopper 1. *X-O System*: Grasshoppers have an X-O sex determination system, where males have XO chromosomes and females have XX chromosomes. 2. *X-Chromosome Presence*: The presence of the X-chromosome determines the sex of the grasshopper. Males have one X-chromosome, while females have two. Sex Determination in Birds 1. *Z-W System*: Birds have a Z-W sex determination system, where males have ZZ chromosomes and females have ZW chromosomes. 2. *Z-Chromosome Dosage*: The number of Z-chromosomes determines the sex of the bird. Males have two Z-chromosomes, while females have one Z and one W. Sex Determination in Humans 1. *X-Y System*: Humans have an X-Y sex determination system, where males have XY chromosomes and females have XX chromosomes. 2. *SRY Gene*: The SRY (sex-determining region Y) gene on the Y-chromosome plays a crucial role in sex determination. It triggers the development of testes in males. #SexDetermination #Drosophila #Grasshopper #Birds #Humans #Genetics #MolecularBiology #XYSexChromosomes #ZWSexChromosomes #SRYGene #SexLethalGene #BiologyEducation #ScienceEducation #GeneticsEducation #SexChromosomes #Chromosomes #DNA #Genome