Biology Inheritance Principle part 36 (Female Heterogamity, human sex determination) class 12 XII

TL;DR

Female heterogamity refers to the presence of different sex chromosomes in females, while males have the same sex chromosomes. In organisms with female heterogamity, the sex of offspring is determined by the female.

Transcript

hello friends this video on principles of inheritance part 36 is brought to you by exam fear dot com no more fear from exam so let us see what is female heterogamity now on similar lines when we say female heterogamity that means in females the sex chromosomes are different but in males they are the same so female hetero in here the female sex of t... Read More

Key Insights

• 🕵️‍♀️ Female heterogamity is uncommon but observed in some insects, reptiles, birds, and butterflies.
• 🕵️‍♀️ In organisms with female heterogamity, the sex of offspring is determined by the female's contribution of sex chromosomes.
• 👪 In humans, sex determination relies on the combination of sex chromosomes contributed by both parents.
• 👶 The father's contribution of either an X or Y chromosome determines the sex of the child.
• 🕵️‍♀️ On average, there is a 50% probability of a child being male or female in each pregnancy.
• 🖐️ Autosomes, which make up the majority of chromosomes, do not play a role in sex determination.

Questions & Answers

Q: What is female heterogamity?

Female heterogamity refers to the presence of different sex chromosomes in females, while males have the same sex chromosomes.

Q: Which organisms exhibit female heterogamity?

Female heterogamity is seen in some insects, reptiles, birds (e.g., chickens), and certain butterflies and moths.

Q: How does female heterogamity affect the sex determination of offspring?

In organisms with female heterogamity, the sex of offspring is determined by the female. Males can only contribute the same sex chromosome, while females can contribute either the same or a different sex chromosome.

Q: How does sex determination occur in human beings?

In humans, sex determination is determined by the sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The combination of sex chromosomes contributed by the father and mother determines the sex of the child.

Summary & Key Takeaways

• Female heterogamity is observed in some insects, reptiles, birds, and butterflies.

• In organisms with female heterogamity, the male has the same sex chromosomes, while the female has different sex chromosomes (such as ZW in birds).

• Offspring sex determination depends on the sex chromosome contributed by the female, with males always contributing the same chromosome.