You Are Mapping the Location of Two Genes in Drosophila,listless

question 44

Multiple Choice

You are mapping the location of two genes in Drosophila,listless l and blind b.(l⁺ l⁺ b⁺ b⁺) and (l⁺ l b⁺ b) flies are normal,but (l l b b) flies don't move around very much and cannot detect the location of a light source.You perform a cross between a true-breeding normally active,sighted fly and a true-breeding listless,blind fly.You testcross an F1 individual with an individual homozygous recessive for both traits and get the following results:
Listless,sighted: 100
Listless,blind: 400
Normal activity,sighted: 400
Normal activity,blind: 100
The recombination frequency observed in experimental crosses can be used to indicate distances between genes on a chromosome.More specifically,the map distance in map units between two genes is equal to the frequency of recombinant offspring.What is the distance between these two genes?

• A)They are on different chromosomes.
• B)They are 10 map units apart.
• C)They are 20 map units apart.
• D)They are 40 map units apart.
• E)They are 80 map units apart.

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Definitions:

Infant Mortality Rate

The rate at which babies under one year old die, often calculated per 1,000 live births.

United States

A country in North America consisting of 50 states and a federal district, known for its large economy and diverse population.

Fairly High

A relative measure indicating a level or amount that is somewhat above average or normal.

Hospice Care

A type of care and philosophy that focuses on the palliation of a chronically ill or terminally ill patient's pain and symptoms, and attending to their emotional and spiritual needs.