A nucleotide consists of:

• A nitrogenous base, a phosphoric acid and a 5-carbon sugar.

• An adenine base, a glucose base and a ribose base.

• A nitrogenous base and a phosphoric acid.

• A nitrogenous base, a phosphoric acid and a 6-carbon sugar.

The cellular localization of nucleic acids:

• DNA is located in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells.

• RNA is located in the nucleus of prokaryotic cells.

• DNA is located in the nucleus and in the cytoplasm of eukaryotic cells.

Indica las frases correctas en relación con la estructura de los cromosomas:

• Sister chromatids are joined by telomeres.

• The DNA molecules which form a sister chromatid of a chromosome are identical.

• The three answers above are all false.

• Sister chromatids do not join together, they simply remain close to each other.

How many nitrogenous bases does the ribosome have to recognise in the mRNA sequence in order to synthesise a protein of 12 amino acids?

• 48

• 12

• 36

• 24

The genetic code establishes correspondence between:

• Messenger RNA and DNA complementary nucleotides.

• Messenger RNA codons and amino acids of a protein.

• DNA complementary nucleotides.

• DNA codons and amino acids of a protein.

At which point of the cellular cycle does DNA duplication take place?

• At the start of the division phase.

• At the end of the division phase.

• During the interphase or growth phase.

• During the mitosis prophase.

In which mitosis phase does chromatin condense to form chromosomes?

• Telophase.

• Prophase.

• Anaphase.

• Metaphase.

During the mitosis metaphase:

• The chromosomes are located in the equator of the cell, forming the equatorial plate.

• The nuclear membrane and nucleoli disappear.

• The sister chromatids of each chromosome separate and are dragged to the poles.

• The homologous chromosomes are separated and are dragged to the poles.

In which phase of the meiotic division do the homologous chromosomes decondense and the nuclear membrane reform?

• Prophase II.

• Telophase I.

• Telophase II.

• Anaphase I.