Learn: Genome

Welcome!Today we'll learn about the genome. The genome is fascinating because it contains all the genetic material of an organism. Let's explore this topic in detail together!

What is a genome?A genome is the complete set of genetic material in an organism. It includes all the DNA, which is made up of genes and non-coding DNA. The genome contains the instructions needed for an organism to develop, survive, and reproduce.

Where is genetic material found?In eukaryotes (organisms with complex cells), genetic material is found in the nucleus. In prokaryotes (organisms with simpler cells like bacteria), it is found in plasmids and cytoplasmic DNA.

Chromosomes and genesIn eukaryotic cells, DNA is organised into structures called chromosomes. These are long molecules of DNA that contain sections called genes. Genes are specific segments of DNA that code for particular traits or proteins.

DNA and its structureDNA stands for deoxyribonucleic acid. It is a polymer made of nucleotides and forms a double helix shape. The DNA sequence contains four bases: A (adenine), T (thymine), C (cytosine), and G (guanine). These bases pair up (A with T, and C with G) to form the rungs of the DNA ladder.

What is the genetic code?The genetic code is the sequence of bases in DNA. It acts as instructions for the cell to create proteins, the building blocks of life. Proteins are made by linking amino acids together in a specific order, determined by the sequence of bases in the DNA.

Alleles: Variants of a geneAn allele is a variant form of a gene. Different alleles can cause variations in traits, like eye colour or height. Your unique combination of alleles is called your genotype, and the traits you show are called your phenotype.

Protein synthesis overviewProteins are created through a process called protein synthesis. This involves mRNA (messenger RNA), which carries the genetic information from DNA to ribosomes. Ribosomes then assemble proteins by linking amino acids together in the order specified by the mRNA sequence.

Mutations and genetic variantsA mutation is a change in the DNA sequence. Mutations can create new genetic variants, which can affect the phenotype (observable traits) of an organism. These changes can occur in coding DNA (affecting proteins directly) or non-coding DNA (affecting gene regulation).

Environmental influences on phenotypeAn organism's phenotype is influenced by its genome and the environment. For example, your genes might determine your potential height, but factors like nutrition and health can affect whether you reach that height.

Review Time!Great work! You've learned about the genome, DNA, chromosomes, genes, protein synthesis, mutations, alleles, and phenotype. Now let's test your understanding with a few questions.