WT Yeast (TRP+) Can Synthesize the Amino Acid Tryptophan and Can

question 40

Multiple Choice

WT yeast (TRP+) can synthesize the amino acid tryptophan and can grow on media plates lacking tryptophan. In contrast, mutant alleles (trp-) block tryptophan synthesis and result in an inability of mutant strains to grow on media lacking tryptophan. A diploid yeast was made through the cross M ADE+ × MATa ade-. Meiosis was induced in the diploid strain to produce an ascus with four haploid spores, which were separated and grown on plates lacking tryptophan. How many spores are expec grow into colonies on the plate?

• A) 0
• B) 3
• C) 4
• D) 1
• E) 2

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Definitions:

Memory Trace

A theoretical construct representing the physical and potentially biochemical changes in the brain associated with a stored memory.

Synaptic Effectiveness

Synaptic effectiveness refers to the efficiency and strength with which a synapse can transmit a signal from one neuron to another.

Long-term Depression (LTD)

A reduction in the effectiveness of neuronal synapses lasting hours or longer following a long patterned stimulus, contributing to the inverse process of synaptic strengthening.

Synaptic Effectiveness

The ability of synapses (junctions between two neurons) to efficiently transmit signals from the presynaptic neuron to the postsynaptic neuron.