Thomas H. Morgan and Sex Determination in Drosophila

What is the significance of autosomes in the sex determination of Drosophila?

Autosomes have no role in sex determination in Drosophila
Autosomes combine with X chromosomes to influence the development of male and female characteristics (correct)
Autosomes are only involved in eye color mutations in Drosophila
Autosomes alone determine the sex of the fruit fly

What distinguishes sex-linked traits from autosomal traits in Drosophila?

Sex-linked traits do not differ from autosomal traits
Sex-linked traits are inherited differently and are located on sex chromosomes (correct)
Sex-linked traits have no influence on eye color mutations
Sex-linked traits are determined by autosomes

What is the purpose of conducting reciprocal crosses in Drosophila genetics?

To test the role of autosomes in sex determination
To confirm that X chromosomes do not influence sex characteristics
To determine if traits are linked on the X chromosome (correct)
To study the impact of mutations in eye color

How does non-disjunction provide support for the Chromosomal theory of inheritance?

Non-disjunction results in an abnormal number of chromosomes, leading to unexpected phenotypes (D) Signup and view all the answers

In Drosophila genetics, what are reciprocal crosses commonly used to investigate?

The inheritance pattern of specific traits and the linkage of genes (C) Signup and view all the answers

How do X chromosomes and autosomes collectively impact the development of male and female characteristics in Drosophila?

Both X chromosomes and autosomes collectively influence the development of male and female traits (D) Signup and view all the answers

What is the main difference between neutral petite mutations and suppressive petite mutations?

Neutral petite mutations lead to normal colonies, while suppressive petite mutations lead to all petite colonies. (C) Signup and view all the answers

In Drosophila, what is the role of maternal effect genes in early embryonic development?

Maternal effect genes control the cleavage pattern of the zygote. (C) Signup and view all the answers

How do nurse cells in snails contribute to embryonic development following fertilization?

Nurse cells transfer gene products, cytoplasm, and organelles to enrich the oocyte's cytoplasm. (C) Signup and view all the answers

How does maternal effect influence the phenotype of the developing zygote in Drosophila?

The zygote's phenotype is solely determined by the genotype of the mother. (B) Signup and view all the answers

What are the consequences of mutations in maternal effect genes in females in the next generation?

The next generation will exhibit abnormalities in body axis formation. (B) Signup and view all the answers

What aspect of development does Developmental Genetics primarily focus on?

Understanding how genes orchestrate changes during an organism's development. (A) Signup and view all the answers

What is the most crucial factor in determining the outcome of a cross involving linked genes?

Specific arrangement of alleles on homologous chromosomes (B) Signup and view all the answers

What is the significance of a recombination frequency of 50% between two genes?

The genes are unlinked (B) Signup and view all the answers

What is the relationship between the distance separating two genes and their recombination frequency?

Recombination frequency is inversely proportional to the distance (D) Signup and view all the answers

What is the characteristic of genes that have a recombination frequency less than 50%?

They are linked genes (B) Signup and view all the answers

What was observed in Cross A of dihybrid crosses for two linked genes in Drosophila studied by Thomas Hunt Morgan?

Mostly parental phenotypes with a small percentage of recombinant phenotypes (B) Signup and view all the answers

What is the characteristic of genes located on independent chromosomes or far apart on a single chromosome?

They are unlinked genes (D) Signup and view all the answers