Lembar kerja Biologi untuk ujian masuk keperawatan dengan jawaban

What is the R group of an amino acid?

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

What does the polymerase chain reaction (PCR) do?

1. AIt makes many copies of a piece of DNA
2. BIt separates proteins by their charge
3. CIt cuts DNA at specific sequences
4. DIt turns RNA into protein

Which enzyme adds new nucleotides to build a new DNA strand?

1. APepsin
2. BDNA polymerase
3. CRNA polymerase
4. DHelicase

What happens to an enzyme after it has catalysed a reaction?

1. AIt changes into the substrate
2. BIt is broken down into amino acids
3. CIt is released unchanged and can be used again
4. DIt becomes part of the product and leaves with it

The human arm, bat wing and whale flipper contain the same set of bones. What does this suggest?

1. AThey are the result of acquired traits
2. BThey have the same function
3. CThey share a common ancestor
4. DThey evolved completely separately

Why is DNA replication called semiconservative?

1. AOnly half of the DNA is copied each time
2. BThe old DNA molecule is kept whole, and a completely new one is made
3. CEach new strand is a random mix of old and new pieces
4. DEach new DNA molecule has one old strand and one new strand

Some chemotherapy drugs stop spindle fibres from forming. Why do they often cause hair loss and damage to the gut lining?

1. AThese tissues also contain rapidly dividing cells
2. BThese cells have no mitochondria
3. CThese cells divide by meiosis instead of mitosis
4. DThese tissues are made only of haploid cells

Bacteria from hot springs have enzymes that work best at about 80 °C, while most human enzymes work best near 37 °C. What is the best explanation?

1. ATheir enzymes are made of lipids, not proteins
2. BHigh temperature never affects any enzyme
3. CTheir enzymes do not have an active site, so heat cannot affect them
4. DTheir enzymes have structures that stay stable at high temperatures