Sex Determination And Inheritance Systems — a labelled NEET Biology diagram with a definitions lexicon.
Sex Determination and Inheritance Systems Labelled parts: Humans, Grasshopper, Birds, XX-XY system, XX-XO system, ZW-ZZ system, X-linked inheritance, X, Y, Z, W, XX, XY, XO, ZZ, ZW, Carrier mother, Normal father, Affected son. The biological process by which the sex of an organism is determined, typically based on the sex chromosomes inherited from the parents. This mechanism is genetically controlled. FYI: In humans, the sex is determined by the sex chromosomes (XX for female, XY for male), and the sperm carries the determinant. The sex determination system found in humans and other mammals, where the female is XX and the male is XY. The Y chromosome carries the primary sex-determining gene (SRY). FYI: The presence of the Y chromosome is sufficient to trigger male development, making the Y chromosome the determinant of male sex. The sex determination system found in birds, reptiles, and some fish, where the female is ZW and the male is ZZ. The Z chromosome is the primary sex-determining chromosome. FYI: In this system, the female is heterogametic (ZW), and the male is homogametic (ZZ). A pattern of inheritance where the gene responsible for a trait is located on the X sex chromosome. These traits are passed down independently of the autosomes. FYI: X-linked recessive disorders (like color blindness) are more commonly observed in males because they only have one X chromosome. A female individual who possesses one recessive allele for a specific genetic disorder but does not express the trait herself due to the presence of a dominant allele. She can pass the gene to her offspring. FYI: A carrier mother is typically phenotypically normal but carries the risk of passing the recessive allele to her children, especially if the father is also a carrier. A male offspring inheriting a recessive sex-linked trait from a carrier mother. This pattern of inheritance is common in X-linked disorders. FYI: Since the mother is a carrier (heterozygous), she has a 50% chance of passing the affected allele to her son if the gene is X-linked.