Genes, Alleles & Genomes Practice Flashcards

A set of practice flashcards covering the distinctions between DNA, genes, alleles, and genomes, including protein functions and the Human Genome Project.

What is DNA and what are the four bases it contains?

DNA stands for deoxyribonucleic acid and contains the four bases adenine, thymine, guanine, and cytosine.

What is chromatin?

Chromatin refers to DNA wound around proteins called histones.

At what point does chromatin become referred to as chromosomes?

Chromatin becomes chromosomes during the cell cycle when it condenses and becomes tightly wound.

What is the definition of a gene?

A gene is a small section of DNA considered the unit of heredity which provides instructions for producing a product, such as a protein.

What is the range of base pairs found in a gene's length?

Genes vary in length from $200$ base pairs to $2000000$ base pairs.

What does the term 'gene expression' refer to?

Gene expression is the reading of a gene and the production of its specific product.

What are five functional types of proteins mentioned in the text?

Enzymes, transport proteins, structural proteins, antibodies, and hormones.

What are alleles?

Alleles are different variations of a gene.

How many copies of each gene does an individual typically have (excluding sex chromosomes)?

Every person has $2$ copies of each gene, one inherited from each parent.

What is a genome?

A genome is the complete set of genetic material in a cell of an organism, measured in base pairs.

Which cells are included when measuring the genome?

The genome measurement only counts genetic material in somatic cells and does not include material in reproductive cells (egg and sperm).

What is genomics?

Genomics is the study of genomes, specifically focusing on how genomes differ between species.

When was the human genome sequenced and by what organization?

The human genome was sequenced in $2003$ by the Human Genome Project, an international collaboration of scientists.

How many base pairs and genes are contained in the human genome?

The human genome contains $3$ billion base pairs and approximately $20000$ genes.