Drosophila Genetics and Biotech: Gene Notation

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What was the significance of Morgan's discovery of the eye colour mutant?

It led to the development of the chromosome theory of inheritance. (correct)
It proved that genes are located on mitochondria.
It demonstrated that genes are inherited in a Mendelian pattern.
It showed that eye colour is determined by environmental factors.

What do the superscript '+' and '-' symbols denote in Drosophila allele notation?

Dominant and recessive alleles, respectively.
Autosomal and sex-linked alleles, respectively.
Wild-type and mutant alleles, respectively. (correct)
Mutant and wild-type alleles, respectively.

What is the significance of correlating the sex of flies with the behaviour of alleles of the eye colour gene?

It demonstrates the concept of epistasis.
It provides evidence for the chromosome theory of inheritance. (correct)
It shows that sex is determined by multiple genes.
It proves that genes are inherited in a Mendelian pattern.

What is the symbol for the mutant white eyes allele in Drosophila?

w (B) Signup and view all the answers

Who developed the simple notation for alleles?

Mendel (A) Signup and view all the answers

What is the expected ratio of phenotypes if the genes assort independently?

1:1:1:1 (A) Signup and view all the answers

What did Morgan's data suggest about the genes controlling body colour and wing size?

That they are genetically linked (D) Signup and view all the answers

Why are closely physically linked genes not expected to assort independently?

Because they are located close together on the same chromosome and move through meiosis as a unit (D) Signup and view all the answers

What is the significance of sister chromatids forming chiasmata in the same homologous chromosome?

It has no genetic consequences because they are identical. (B) Signup and view all the answers

What is the result of recombination between linked genes?

The genes are separated and move through meiosis independently (D) Signup and view all the answers

What is the recombination rate between the b and vg genes in Drosophila melanogaster?

17% (D) Signup and view all the answers

What is the significance of the experiment with Drosophila melanogaster?

It demonstrated the concept of genetic linkage (B) Signup and view all the answers

Who developed the idea of a genetic map in 1913?

Alfred H. Sturtevant (B) Signup and view all the answers

What is the purpose of recombination rates in genetics?

To determine the genetic map of genes on a chromosome (D) Signup and view all the answers

What is the relationship between the genes b, vg, and cn?

They are linked genes on the same chromosome (A) Signup and view all the answers

What is the genetic makeup of the wild-type females used in the experiment?

b+ b+ vg+ vg+ (A) Signup and view all the answers

Which of the following statements is true about the genes controlling body colour and wing size?

They are autosomal genes. (C) Signup and view all the answers

What is the effect of the vg allele on the wing size of Drosophila melanogaster?

It results in vestigial wings. (C) Signup and view all the answers

What is the relationship between the b+ and b alleles?

b is recessive to b+. (D) Signup and view all the answers

What is the purpose of crossing wild-type females with males having both mutant phenotypes in the experiment?

To study the inheritance pattern of autosomal genes. (D) Signup and view all the answers

What can be concluded from the image of the homologous chromosomes with a specific gene tagged with a fluorescent yellow dye?

Genes are DNA sequence segments located on chromosomes. (C) Signup and view all the answers

What was the significance of Thomas Hunt Morgan's work in the early 1900s?

He provided solid evidence associating a specific gene with a specific chromosome. (B) Signup and view all the answers

What is the relationship between genes and chromosomes?

Genes are located on chromosomes. (A) Signup and view all the answers

What is the expected ratio of parental phenotypes in the offspring if linkage is complete between two genes?

1:1 (C) Signup and view all the answers

What can be inferred about the image of the homologous chromosomes?

The chromosomes have duplicated and each has two sister chromatids. (B) Signup and view all the answers

What is the process by which recombinant chromosomes and phenotypes are generated?

Genetic recombination (B) Signup and view all the answers

What is the term for the X-shaped structure between chromatids in a tetrad during meiosis?

Chiasma (A) Signup and view all the answers

What is the concept that describes the connection between genes and chromosomes?

The chromosomal theory of inheritance. (C) Signup and view all the answers

What is the result of crossing-over between linked genes?

Recombinant phenotypes (B) Signup and view all the answers

What is the name of the process by which alleles from different genes are brought together in new combinations?

Genetic recombination (A) Signup and view all the answers

What is the term for the normal phenotype for a character in Drosophila genetics?

Wild type (D) Signup and view all the answers

How many chromosomes are present in a haploid gamete in Drosophila melanogaster?

4 (D) Signup and view all the answers

What is the sex chromosome composition of a male Drosophila melanogaster?

XY (B) Signup and view all the answers

What was the significance of Morgan's discovery of an eye color mutant in Drosophila melanogaster?

It showed that genes are located on specific chromosomes (D) Signup and view all the answers

How many pairs of chromosomes are present in a diploid Drosophila melanogaster cell?

4 (C) Signup and view all the answers

What is the term for an alternative trait to the wild type in Drosophila genetics?

Mutant phenotype (D) Signup and view all the answers

What is the probability of a sperm having an X chromosome in Drosophila melanogaster?

50% (B) Signup and view all the answers

What is the sex chromosome composition of a female Drosophila melanogaster?

XX (C) Signup and view all the answers

What is assumed to be the origin of mutant alleles in Drosophila genetics?

Changes in the wild type allele (D) Signup and view all the answers

What is the total number of chromosomes in a diploid Drosophila melanogaster cell?

8 (B) Signup and view all the answers