Biology for nursing entrance exams worksheet with answers

What does the enzyme DNA ligase do?

1. AIt cuts DNA at specific sites
2. BIt joins pieces of DNA together
3. CIt makes RNA from a DNA template
4. DIt unwinds the DNA double helix

Where is most of the DNA of a eukaryotic cell found?

1. AIn the cell wall
2. BIn the cell membrane
3. CIn the lysosomes
4. DIn the nucleus

Which carbohydrate forms plant cell walls and acts as dietary fibre?

1. AGlycogen
2. BGlucose
3. CCellulose
4. DLactose

In disease spread, what is a vector?

1. AAn organism that carries a pathogen between hosts
2. BA medicine that destroys a pathogen in the body
3. CA blood test used to detect antibodies
4. DThe first person to catch a disease

A bone marrow transplant can treat some blood cancers. Why does it work?

1. AThe donor marrow contains antibiotics that kill cancer
2. BThe transplant replaces the patient's bones
3. CThe donor stem cells produce new, healthy blood cells
4. DThe donor red cells divide to make more red cells

A patient's blood type is B positive. What does this mean?

1. ATheir red cells carry the A antigen and no RhD antigen
2. BTheir red cells carry no antigens at all
3. CTheir plasma contains anti-B antibodies
4. DTheir red cells carry the B antigen and the RhD antigen

The antibiotic tetracycline binds to bacterial ribosomes. Which process does it block, and why are human cells much less affected?

1. ATranslation, because bacterial ribosomes differ from human ribosomes
2. BDNA replication, because bacteria have no DNA polymerase
3. CTranscription, because human cells have no RNA polymerase of their own
4. DTranslation, because human cells have no ribosomes

In Tay-Sachs disease, a lysosomal enzyme does not work. What happens inside the affected nerve cells?

1. AThe ribosomes stop making proteins
2. BThe cells can no longer make ATP in their mitochondria
3. CThe DNA cannot be copied before division
4. DThe undigested substance builds up inside lysosomes