Biology for nursing entrance exams worksheet with answers

Which statement describes bacteria?

1. AThey are not cells but particles of protein and DNA
2. BThey are many-celled organisms like plants
3. CThey are single-celled prokaryotes
4. DThey are single-celled eukaryotes with a nucleus

Which bonds hold the two strands of a DNA double helix together?

1. AHydrogen bonds between the bases
2. BIonic bonds between the phosphates
3. CPeptide bonds between the sugars
4. DDisulfide bonds between the bases

What does transfer RNA (tRNA) do?

1. AIt joins two DNA strands together
2. BIt carries the code out of the nucleus
3. CIt copies DNA in the nucleus
4. DIt brings amino acids to the ribosome

Two heterozygous parents (Aa × Aa) are crossed. What is the expected genotype ratio?

1. A1 AA : 2 Aa : 1 aa
2. B1 AA : 1 aa
3. C2 AA : 1 Aa : 1 aa
4. D3 AA : 1 aa

A woman with blood type O has a child with a man of type AB. Which blood types can their children have?

1. AO or AB
2. BO only
3. CA or B
4. DA, B, AB or O

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

Which parent's gamete decides the biological sex of a human baby, and why?

1. AThe mother's, because an egg carries either an X or a Y
2. BThe father's, because a sperm carries either an X or a Y
3. CBoth equally, because each gives one Y chromosome
4. DThe mother's, because she gives two X chromosomes

A single-celled organism has a nucleus, no cell wall and swims using cilia. In which group is it best placed?

1. APlants
2. BProtists
3. CBacteria
4. DFungi