Podcast
Questions and Answers
In the XX-XY sex determination system, which of the following statements is true?
In the XX-XY sex determination system, which of the following statements is true?
- Males produce only X gametes.
- Females produce both X and Y gametes.
- All somatic cells in human females contain one X and one Y chromosome.
- Males inherit their X chromosome from their father and their Y chromosome from their mother. (correct)
How many genes are there on the Y chromosome compared to the X chromosome in humans?
How many genes are there on the Y chromosome compared to the X chromosome in humans?
- Equal number of genes on both X and Y chromosomes
- 900–1400 genes on the Y chromosome and ~75 genes on the X chromosome (correct)
- Y chromosome has more genes than the X chromosome
- Both X and Y chromosomes have around 1000 genes
What determines maleness in the XX-XY sex determination system?
What determines maleness in the XX-XY sex determination system?
- Sperm cells that carry the X chromosome
- Females producing only X gametes
- Presence of two X chromosomes
- Sperm cells that carry the Y chromosome (correct)
During early development, every human embryo is potentially hermaphroditic until around which week of gestation?
During early development, every human embryo is potentially hermaphroditic until around which week of gestation?
At what stage does the gonadal tissue of a human embryo become sexually indifferent or neutral?
At what stage does the gonadal tissue of a human embryo become sexually indifferent or neutral?
Which part of the neutral gonadal tissue may develop into a testis in a human embryo?
Which part of the neutral gonadal tissue may develop into a testis in a human embryo?
In humans, how many X chromosomes do males inherit from each parent?
In humans, how many X chromosomes do males inherit from each parent?
Which type of sex cells do females produce in the XX-XY sex determination system?
Which type of sex cells do females produce in the XX-XY sex determination system?
What can be distinguished at the stage where the gonadal phenotype is sexually indifferent?
What can be distinguished at the stage where the gonadal phenotype is sexually indifferent?
What determines maleness in humans according to the XX-XY sex determination system?
What determines maleness in humans according to the XX-XY sex determination system?
In the XX-XO system, which of the following accurately describes the determination of maleness?
In the XX-XO system, which of the following accurately describes the determination of maleness?
What is the role of the Wolffian ducts and Müllerian ducts in each embryo?
What is the role of the Wolffian ducts and Müllerian ducts in each embryo?
What is the function of the testis determining factor?
What is the function of the testis determining factor?
What are the pseudoautosomal regions (PARs) critical for?
What are the pseudoautosomal regions (PARs) critical for?
What genetic consequences result from having more than two copies of pseudoautosomal regions (PARs)?
What genetic consequences result from having more than two copies of pseudoautosomal regions (PARs)?
What is the function of Barr bodies in somatic cells of females?
What is the function of Barr bodies in somatic cells of females?
According to the Lyon hypothesis, when does X chromosome inactivation occur?
According to the Lyon hypothesis, when does X chromosome inactivation occur?
What is the basis for sex determination in organisms with Haplodiploidy?
What is the basis for sex determination in organisms with Haplodiploidy?
What is the mechanism of sex determination in organisms with XX-XY system?
What is the mechanism of sex determination in organisms with XX-XY system?
In Drosophila melanogaster, which one of the following accurately describes the sex-linkage pattern for the gene controlling eye color?
In Drosophila melanogaster, which one of the following accurately describes the sex-linkage pattern for the gene controlling eye color?
What did Calvin Bridges' observation of flies with unusual phenotypes cytogenetically confirm?
What did Calvin Bridges' observation of flies with unusual phenotypes cytogenetically confirm?
Which statement accurately represents Morgan’s Hypothesis on X-linkage in Drosophila melanogaster?
Which statement accurately represents Morgan’s Hypothesis on X-linkage in Drosophila melanogaster?
What was the significance of conducting reciprocal crosses in the study of sex-linkage in Drosophila?
What was the significance of conducting reciprocal crosses in the study of sex-linkage in Drosophila?
What did the observation of unexpected phenotypes at a frequency more than the expected mutation rate in Morgan’s crosses indicate?
What did the observation of unexpected phenotypes at a frequency more than the expected mutation rate in Morgan’s crosses indicate?
What was one result of X-linkage according to Morgan’s hypothesis?
What was one result of X-linkage according to Morgan’s hypothesis?
Which of the following accurately describes the F1 offspring obtained in a reciprocal cross for an autosomal gene or trait?
Which of the following accurately describes the F1 offspring obtained in a reciprocal cross for an autosomal gene or trait?
In Morgan’s studies, what did the observation of a white eyed male fly as opposed to red eyed flies lead to?
In Morgan’s studies, what did the observation of a white eyed male fly as opposed to red eyed flies lead to?
What genetic phenomenon did Calvin Bridges' observation confirm about the flies with unusual phenotypes?
What genetic phenomenon did Calvin Bridges' observation confirm about the flies with unusual phenotypes?
What did Bridges' observation confirm about the flies' rare phenotypes?
What did Bridges' observation confirm about the flies' rare phenotypes?
What is the sex determination system present in butterflies, birds, some reptiles, and amphibians?
What is the sex determination system present in butterflies, birds, some reptiles, and amphibians?
According to Bridges, what plays a critical role in sex determination in Drosophila melanogaster?
According to Bridges, what plays a critical role in sex determination in Drosophila melanogaster?
What did Thomas H. Morgan observe in his Drosophila lab cultures, leading to his studies of sex-linkage?
What did Thomas H. Morgan observe in his Drosophila lab cultures, leading to his studies of sex-linkage?
What was Morgan's hypothesis regarding the allele for white eyes in Drosophila?
What was Morgan's hypothesis regarding the allele for white eyes in Drosophila?
What is the definitive method to test for sex-linkage?
What is the definitive method to test for sex-linkage?
In a reciprocal cross, if the gene or trait is autosomal, what will be observed in the offspring?
In a reciprocal cross, if the gene or trait is autosomal, what will be observed in the offspring?
What is observed in the offspring of a reciprocal cross if the gene or trait is sex-linked?
What is observed in the offspring of a reciprocal cross if the gene or trait is sex-linked?
What did Calvin Bridges observe under the microscope to confirm his hypothesis regarding unusual phenotypes?
What did Calvin Bridges observe under the microscope to confirm his hypothesis regarding unusual phenotypes?
What did unexpected phenotypes appearing at a frequency more than the expected mutation rate provide definite proof for?
What did unexpected phenotypes appearing at a frequency more than the expected mutation rate provide definite proof for?
