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Glucose connects molecular structure, energy release and physiological regulation. (a) Distinguish alpha-glucose and beta-glucose in structure and biological role. (b) Explain the regulation that prevents large sustained changes in human blood glucose…
A thermocycler repeats DNA strand separation, primer binding and strand extension. Which change correctly connects the primer-binding and extension stages? A. The temperature rises from the annealing range towards the polymerase’s extension temperature B. The…
Inherited information is encoded in DNA and expressed in phenotypes. (a) Draw a DNA segment containing two base pairs. Label its nucleotide components and the interactions between the bases. (b) Describe how whole-genome sequencing can be used to infer…
A ribosome is elongating a polypeptide. Which arrangement allows the next peptide bond to form? A. Two mRNA templates are aligned in the large subunit B. A tRNA carrying the growing chain and an aminoacyl-tRNA occupy adjacent ribosomal sites C. The DNA…
Membranes support water balance, electrical signalling and energy conversion. (a) Outline what happens to cells in a piece of plant tissue transferred to a hypotonic solution. (b) Describe the establishment and maintenance of a resting membrane potential in a…
A candidate gene may be required for yeast cells to use a particular sugar. Which technique would most directly test its function? A. Measure the total mass of extracted DNA B. Increase the number of copies of a nearby non-coding fragment by PCR C. Determine…
Which schematic represents a typical mature eukaryotic messenger RNA after processing? A. Schematic A B. Schematic B C. Schematic C D. Schematic D
Chemical messages coordinate cells and whole organisms. (a) Describe bacterial quorum sensing. (b) Outline roles of calcium ions in animal-cell signalling. (c) Explain how plant hormones regulate growth through signalling.
Researchers use CRISPR–Cas9 to correct a defective DNA sequence in cultured cells. Which description best identifies the basis of this approach? A. Selective destruction of all messenger RNA in the cell B. Replacement of the entire nucleus with a bacterial…
The same DNA region is sequenced before and after replication. Original: ACGTCCATGATC Replicated: ACGTTCATGATC Which change is present? A. One base has been replaced while sequence length stays constant B. One extra triplet has been inserted C. One nucleotide…