DNA + Chromosomes + Genes

What is DNA?

A polymer that carries genetic information in living organisms.

What does DNA stand for?

Deoxyribonucleic acid.

Where is most DNA found in a eukaryotic cell?

In the nucleus, organised into chromosomes.

What is a chromosome?

A long DNA molecule associated with proteins, carrying many genes.

What is a gene?

A small section of DNA that codes for a sequence of amino acids in a protein.

What is the genome?

The entire genetic material of an organism.

What is an allele?

An alternative form of a gene.

What is a locus?

The position of a gene on a chromosome.

What are homologous chromosomes?

A pair of chromosomes containing the same genes at corresponding positions, although their alleles may differ.

Why do body cells usually contain chromosomes in pairs?

One chromosome of each pair is inherited from each parent.

How many pairs of chromosomes do humans normally have?

23 pairs.

What are autosomes?

Chromosomes that are not sex chromosomes.

How many pairs of autosomes do humans normally have?

22 pairs.

What are sex chromosomes?

Chromosomes involved in determining biological sex, usually X and Y in humans.

What is the relationship between DNA, genes and chromosomes?

Genes are sections of DNA, and DNA is organised into chromosomes.

What determines the sequence of amino acids in a protein?

The sequence of bases in the gene.

Why can different alleles produce different characteristics?

They may contain different DNA base sequences, affecting the proteins produced.

What is inherited from parents?

Genetic information in the form of DNA and alleles.

Why is DNA important for inheritance?

It contains instructions passed from parents to offspring.