DNA stands for ____ acid. It is a chemical made up of two long molecules. The molecules are arranged in a spiral, like a twisted ____. We call this the double ____ structure. There is ____ in the ____ of every cell. DNA carries ____ information. It has all the ____ that a living organism needs to grow, ____ and function. ____ are short sections of DNA. Genes carry information for particular ____, such as ear shape or ____. Different sets of genes carry information for different characteristics. There are ____ genes in a chromosome. In a cell nucleus, DNA is organised into coiled strands called chromosomes. Humans have ____ chromosomes in each cell. ____ the chromosomes are inherited from one parent and half from the other. As humans, therefore, we have ____ chromosomes from each parent. This explains why organisms can ____ characteristics from both parents. A child, for example, might have red hair like their dad and long fingers like their ____. An egg cell must contain 23 chromosomes as it ____ with the sperm cell which also has 23 chromosomes, when ____ occurs.

Inheritance

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