Биология для вступительных экзаменов на сестринские программы: лист заданий с ответами

What is the R group of an amino acid?

1. AThe peptide bond between two amino acids
2. BThe carboxyl group at one end
3. CThe amino group that is shared by all amino acids
4. DThe side chain that differs between amino acids

What is the active site of an enzyme?

1. AThe product formed by the reaction
2. BThe part of the cell where the enzyme is made
3. CThe gene that codes for the enzyme
4. DThe region where the substrate binds

Что такое гипотеза в научном методе?

1. AВывод, доказанный как истинный
2. BСписок выполненных измерений
3. CШирокое объяснение, подтверждённое многими экспериментами
4. DПроверяемое объяснение или предположение

How can bacteria pass antibiotic-resistance genes directly to other bacteria?

1. ABy mitosis, sharing copies of their chromosomes with neighbours
2. BBy conjugation, transferring plasmids through a pilus
3. CBy osmosis, moving genes in water
4. DBy meiosis, forming gametes with new alleles

What is the difference between an epidemic and a pandemic?

1. AA pandemic spreads across many countries or continents
2. BA pandemic affects only one town
3. CAn epidemic affects the whole world at once
4. DAn epidemic is caused only by bacteria

A deletion removes exactly three bases, forming one whole codon, from the middle of a gene. What is the most likely result?

1. AThe protein becomes three times longer
2. BEvery amino acid after the deletion is changed to a new one
3. CThe protein lacks one amino acid but the rest is unchanged
4. DNo protein can be made at all

Why are mutations in mitochondrial DNA passed on only from mothers to their children?

1. AThe zygote's mitochondria come from the egg
2. BOnly women have mitochondria in their cells
3. CMitochondrial DNA is on the X chromosome
4. DSperm cells contain no DNA at all

Scientists put a human gene into bacteria to make a protein. Why do they use a DNA copy made from the mature mRNA instead of the gene taken straight from human DNA?

1. ABacteria cannot read human codons
2. BBacteria have no ribosomes
3. CBacteria cannot remove introns
4. DHuman DNA has no start codons