Chapter 2 Multiple choice questions

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. Which one of the following elements appears in mature mRNA?

Intron correct incorrect

Exon correct incorrect

Promoter correct incorrect

Enhancer correct incorrect

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. Which one of the following best defines 'epigenetic'?

The sequence of bases in a gene correct incorrect

Methylation of histones in chromatin correct incorrect

Splice factors present in the cell correct incorrect

Any influence on cell behaviour that is not in the sequence of bases in a gene itself correct incorrect

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. Which one of the following appears in mammalian and bacterial cells?

Cell wall correct incorrect

Ribosomes correct incorrect

Golgi apparatus correct incorrect

Mitochondria correct incorrect

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. Which of the following best defines a housekeeping gene?

Any gene used to maintain the body correct incorrect

Any gene that is active in all nucleated cells correct incorrect

A gene that is active only in cells that run the body's core metabolism correct incorrect

A gene that is active only in cells concerned with excretion correct incorrect

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. Which one of the following correctly represents the sequence of events/locations in the synthesis and release of a protein secreted from a mammalian cell?

Endoplasmic reticulum, Golgi apparatus, secretory vesicle, fusion with plasma membrane correct incorrect

Golgi apparatus, endoplasmic reticulum, secretory vesicle, fusion with plasma membrane correct incorrect

Secretory vesicle, endoplasmic reticulum, Golgi apparatus, fusion with plasma membrane correct incorrect

Secretory vesicle, Golgi apparatus, endoplasmic reticulum, fusion with plasma membrane correct incorrect

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. Which of the following is the best explanation of stable states of gene expression in differentiated cells?

The set of genes expressed in the cell includes transcription factors that together activate precisely that set of genes, and no more. correct incorrect

The set of genes expressed in the cell includes transcription factors that together activate precisely that set of genes, and includes repressors that repress expression of other genes. correct incorrect

The set of genes expressed in the cell includes transcription factors that can together activate/repress genes to select precisely that set, and signals from this and neighbouring cells ensure appropriate activation of these transcription factors. correct incorrect

The genes expressed in a differentiated cell all have promoters responding to the same 'master controller' transcription factor, which maintains their activity. correct incorrect

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. Which of the following is NOT a typical feature of mammalian cell culture?

Culture in a bicarbonate-containing buffer in 5% CO₂ correct incorrect

Culture at 37º C correct incorrect

Culture in complex media containing vitamins and hormones as well as nutrients correct incorrect

Culture on agar correct incorrect

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. Why are human cells not cultured with cells of other mammals and birds in most laboratories?

Cells of different mammals need very different culture conditions. correct incorrect

There is a risk of growing a novel, hybrid animal in the dish. correct incorrect

Mixing human and non-human material in this way is considered unethical in some religions. correct incorrect

Viruses that may be present in the animal cells might easily enter and adapt to growth in human cells, risking the creation of a novel dangerous pathogen. correct incorrect

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. What is the Hayflick limit?

The maximum number of times an untransformed cell will proliferate correct incorrect

The maximum number of times a transformed cell will proliferate correct incorrect

The maximum number of generations for which a transgenic animal will multiply correct incorrect

The maximum number of generations of a cell in which a synthetic biological construct will persist correct incorrect

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. Which of the following best describes what typical untransformed mammalian cells require to survive?

Contact with the correct extracellular matrix correct incorrect

Contact with appropriate neighbouring cells correct incorrect

Presence of specific growth factors correct incorrect

All of the above correct incorrect