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

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 region where the substrate binds
4. DThe gene that codes for the enzyme

Почему вирус не может размножаться самостоятельно?

1. AУ него вообще нет генетического материала — ни ДНК, ни РНК
2. BОн размножается только на солнечном свете
3. CОн делится только путём мейоза
4. DЕму нужен аппарат клетки-хозяина для создания копий

What does phloem carry in a plant?

1. AWater from the roots only
2. BChlorophyll to the stem
3. CSugars made in the leaves
4. DCarbon dioxide from the air

Почему красно-зелёная цветовая слепота чаще встречается у мужчин, чем у женщин?

1. AАллель расположен на Y-хромосоме
2. BАллель доминантен у мужчин и рецессивен у женщин
3. CУ мужчин одна X-хромосома, поэтому достаточно одного аллеля
4. DЖенщины не могут унаследовать аллель от отцов

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

1. ANo protein can be made at all
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. DThe protein becomes three times longer

What do nitrogen-fixing bacteria do?

1. AThey convert nitrogen gas into compounds that plants can use
2. BThey release nitrogen gas from dead organisms into the air
3. CThey break down proteins into glucose
4. DThey turn carbon dioxide into sugar

Why does the influenza vaccine need to be updated most years?

1. AThe vaccine damages the immune system after one year, so it must be repeated
2. BInfluenza is caused by a different bacterium each year
3. CAntibodies cannot be made against viruses
4. DThe virus keeps changing its surface proteins through mutation

After wolves are removed from a park, the deer population rises sharply and young trees are overgrazed. What does this show?

1. AWolves compete with trees for sunlight
2. BOrganisms in a food web depend on each other
3. CDeer are producers in the food web
4. DRemoving a predator has no effect on plants