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

How many strands does an RNA molecule usually have?

1. AOne
2. BFour
3. CTwo
4. DThree

Which group of biomolecules forms the basic bilayer of the cell membrane and also stores long-term energy?

1. ALipids
2. BProteins
3. CNucleic acids
4. DCarbohydrates

What is an adaptation?

1. AA change an organism makes during its lifetime that it then passes on
2. BAny mutation that damages a gene
3. CA disease that weakens a population
4. DAn inherited trait that helps an organism survive in its environment

Why can small nonpolar molecules cross the cell membrane easily while ions cannot?

1. AIons are larger than most membrane proteins
2. BThe membrane is made mostly of long carbohydrate chains
3. CThe bilayer's core is made of hydrophobic tails
4. DThe membrane carries a strong positive charge

What are introns?

1. ANon-coding sections removed from pre-mRNA before translation
2. BCoding sections joined together to form the mature mRNA
3. CShort pieces of DNA made on the lagging strand
4. DCodons that tell the ribosome to stop translation

What is the role of ribosomal RNA (rRNA)?

1. AIt forms part of the ribosome and helps join amino acids
2. BIt stores genetic information in the nucleus
3. CIt brings single amino acids to the ribosome
4. DIt carries the code from DNA to the ribosome

Starch and cellulose are both made of glucose. Why can humans digest starch but not cellulose?

1. ACellulose contains no glucose units at all, only fructose
2. BCellulose dissolves in water but starch does not
3. CStarch is a protein, and cellulose is a lipid
4. DHumans lack an enzyme that breaks the bonds in cellulose

В образце ДНК содержится 30% аденина. Какой процент оснований составляет гуанин?

1. A70%
2. B20%
3. C30%
4. D40%