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

What is a karyotype?

1. AA map of the organelles inside a cell
2. BA diagram of a family's inheritance pattern
3. CA list of all the proteins that a cell makes during its life
4. DA picture of a cell's chromosomes arranged in pairs by size

What is a mutagen?

1. AAn enzyme that copies DNA
2. BA cell that divides without control
3. CSomething that can cause changes in DNA
4. DA protein that repairs damaged DNA

Which sex chromosomes does a typical human male have?

1. AXY
2. BYY
3. CX only
4. DXX

During which division of meiosis do homologous chromosomes separate?

1. AMeiosis I
2. BMeiosis II
3. CBoth meiosis I and meiosis II
4. DNeither, because they separate in mitosis

A person catches chickenpox once and does not usually become ill with it again. Why?

1. AAntibodies from the first infection turn into new viruses
2. BThe skin becomes thicker after the first infection
3. CMemory cells give a faster, stronger response the next time
4. DThe virus stays in the blood and kills new viruses

The sodium-potassium pump moves ions across the cell membrane. What does one cycle of the pump do?

1. AMoves 3 Na⁺ out and 2 K⁺ in, using ATP
2. BMoves 3 K⁺ out and 2 Na⁺ in, using ATP
3. CMoves Na⁺ in and K⁺ out, without using ATP
4. DMoves 2 Na⁺ out and 3 K⁺ in, using ATP

Точечная мутация меняет кодон GAA на GAG, и оба кодируют глутаминовую кислоту. К какому типу относится эта мутация?

1. AМутация со сдвигом рамки считывания
2. BХромосомная делеция
3. CМолчащая (синонимичная) мутация
4. DНонсенс-мутация

People who carry one sickle cell allele are more resistant to malaria. Why is the allele common in regions where malaria is widespread?

1. AMalaria causes the sickle cell mutation directly
2. BPeople with two sickle alleles are fully healthy there
3. CNatural selection favours the heterozygotes there
4. DThe allele is dominant, so it spreads by itself