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

What are round (spherical) bacteria called?

1. AVibrios
2. BBacilli
3. CCocci
4. DSpirilla

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

1. APeptide bonds between the sugars
2. BIonic bonds between the phosphates
3. CHydrogen bonds between the bases
4. DDisulfide bonds between the bases

What is an antigen?

1. AA molecule that the immune system sees as foreign
2. BA drug that kills viruses
3. CA protein that carries oxygen
4. DA white blood cell that engulfs and digests bacteria

Какая последовательность комплементарна цепи ДНК A-T-G-C-C-A?

1. AU-A-C-G-G-U
2. BA-T-G-C-C-A
3. CG-C-A-T-T-G
4. DT-A-C-G-G-T

To insert a human gene into a bacterial plasmid, scientists cut both the gene and the plasmid with the same restriction enzyme. Why?

1. ASo the plasmid loses all its genes
2. BSo the gene is turned into RNA
3. CSo the cut ends match and can join together
4. DSo both pieces become exactly the same length

Why can an electron microscope show more detail than a light microscope?

1. AElectrons have a much shorter wavelength than light
2. BElectrons are brighter than light
3. CElectron microscopes use stronger glass lenses
4. DElectron microscopes use living cells only

Home pregnancy tests use antibodies that bind the hormone hCG. Why do they react with hCG and not with other proteins in urine?

1. AThe hormone hCG is a type of antibody itself
2. BUrine contains no other proteins at all
3. CAntibodies bind every protein but change colour only with hCG
4. DEach antibody binds a specific antigen shape

Why can O-negative red blood cells be given to patients of almost any blood type in an emergency?

1. AThey carry all of the A, B and RhD antigens
2. BThey carry no A, B or RhD antigens
3. CTheir plasma contains anti-A and anti-B antibodies
4. DThey have no haemoglobin to react with