Inheritance
Science: KS3, topic 1.2.17
Inheritance
Parents pass on various characteristics through DNA to their offspring. This passing on of DNA is how children acquire their parent's characteristics. This passing on of DNA is called inheritance.
Inheritance of characteristics
- Characteristics are passed on from parent to offspring via their genes within their DNA.
- Examples of characteristics that are passed down include:
- Blood group
- Eye colour
- However sometimes genetic diseases are also passed through DNA.
- Examples of some genetic diseases include:
- Cystic fibrosis
- Down syndrome
DNA and chromosomes
- There are 46 chromosomes in the nucleus of each cell in the human body.
- These chromosomes are arranged into 23 pairs.
- The only exceptions are the gametes (sperm and egg).
- Chromosomes are small sections of DNA.
- DNA stands for deoxyribonucleic acid.
Genes
- A gene is small section of a chromosome.
- Genes are the instructions that code for a certain protein,
- Alleles are small variations of genes.
Test yourself on Inheritance
Which of these traits is passed down through DNA?
Which human cells are also called the gametes?
Select the correct statement about human chromosomes
Chromosomes are small sections of DNA, and genes are small sections of chromosomes. Which of these lists DNA, chromosomes and genes in order from largest to smallest?
Which of these best explains why a baby might be born with Down syndrome?