A genome is all of the DNA of an organism.

A gene is a section of DNA that holds the genetic code for a protein.

A protein a chemical substance whose structure is coded for by the genetic code in genes.

The phenotype is the physical characteristics of an organism.

An enzyme is a functional protein that acts as a biological catalyst to speed up chemical reactions.

The genome, the environment and phenotype

Combined science

The genome

The structure of DNA

Pupils will learn about dominant and recessive alleles, and how to use models of single gene inheritance to make predictions about the genotypes and phenotypes of offspring.

Pupils learned about flower structure, wind and insect pollination, fertilisation, seed and fruit formation and dispersal.

This unit covers the structure and function of eukaryotic and prokaryotic cells, DNA as the genetic material, and key genetic terms. It also explains protein synthesis, genetic variants, and how DNA structure affects proteins. The emphasis is on using models to explain scientific concepts.

DNA and the genome

Genes are instructions to the cell to make what kind of molecule?

The order of nucleotides in a gene controls the structure of a protein. The structure of a protein decides whether it is a structural or {{}} protein.

a functional protein that speeds up chemical reactions

the physical characteristic of an organism

can be structural or functional; has a structure coded for by a gene

Which phenotype is determined **only** by inherited genes?

The height that a sunflower grows to is part of its phenotype. Which factors affect this phenotype?

Its genetic code is for the structure of an enzyme.

The enzyme allows it to speed up a chemical reaction.

Coloured pigments are produced by chemical reactions in the cells of the iris.

The production of coloured pigments causes the colour of the eye.

Order the statements to explain how genes cause the iris of a human eye to have colour.

all the DNA in one species, such as humans

Which type of organism does **not** store its genome in the cell nucleus?

A single straight strand of nucleic acid.

A single strand of nucleic acid twisted into a helix.

Two strands of nucleic acid joined together to form a ladder-like structure.

Two strands of nucleic acid joined together and twisted into a double helix.

What is the best description of the structure of DNA?

The term “{{}} code” is used to describe the order of nucleotides in a gene.

Starter Quiz

What does the photograph show?