Suppose That a Mutant Organism Is Unable to Make the Amino

question 46

Multiple Choice

Suppose that a mutant organism is unable to make the amino acid arginine. Knowing that the metabolic pathway to production of arginine is ornithine - citrulline - arginosuccinate -arginine, you test the ability of the mutant to grow in the presence of each one of these compounds, providing just one of the compounds in each of your tests. Also suppose that you find that the mutant can grow in the presence of arginosuccinate or arginine, but NOT in the presence of citrulline or ornithine. From this information, which step in the metabolic pathway do you think is blocked?

• A)citrulline to arginosuccinate
• B)arginosuccinate to arginine
• C)ornithine to citrulline
• D)ornithine to arginosuccinate

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Definitions:

Meiosis

A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, critical for sexual reproduction.

Sperm Cell

The male reproductive cell, capable of fertilizing an egg to produce offspring.

Chromosomes

Filamentous entities present within the nucleus of both plant and animal cells, composed of protein and a singular DNA molecule, responsible for transmitting genetic data.

Half-Siblings

Biological siblings who share one parent in common but not both.