1. DNA, Chromosomes & Genes

2. Overview What is DNA and where it is found?
What is a chromosome and where are they found?
What is a gene and where are they found?
How do we obtain our genes?

3. What is DNA?

4. It is identical in each cell.
What is DNA?
DNA is a molecule found inside the nucleus of each of the trillions of cells of your body.
It is identical in each cell.

5. What is the structure of DNA?
DNA is made from two strands, bonded and twisted together to form a double helix.

6. What does DNA stand for? DNA stands for deoxyribonucleic acid
Because the rails of the DNA are made up of alternating phosphate groups and sugars called deoxyribose.
Attaching a base (the rungs), makes the molecule a nucleic acid.

7. What are CHROMOSOMES?

8. What are CHROMOSOMES?
A packet of one tightly coiled up DNA strand ( so it can fit inside your nucleus)
Humans have 46 chromosomes per cell.

9. What are CHROMOSOMES? A chromosome is about 0.004 mm long
The DNA is about 4-5 cm long or mm long
This is about 10 000 times longer than the chromosome
So it has to twist and coil to fit inside

10. What is a GENE?

11. What is a GENE?
A specific sequence of bases carried on the DNA molecule.
These sequences are a code for the production of specific proteins needed inside your body
Each DNA molecule contains thousands of genes

12. What is a GENE?
Each gene contains information that your body needs to function and to express your behavioural and physical traits.
99.9% of your DNA is identical to everyone else's

13. What is a GENE?
The remaining 0.1% influences the differences between us
height, hair color and susceptibility to a particular disease
Environmental factors, such as lifestyle (for example, smoking and nutrition) also influence the way we look and our susceptibility to disease

14. What is the genome?
The complete set of genes of an organism (found in each cells nucleus.

15. How are genes inherited?
Genes come in pairs and children inherit one copy of each gene from each parent at conception
-so you might share a trait with one parent, both or be a combination of your parents for each trait.

16. The passing of traits from parent to offspring
Define HEREDITY
The passing of traits from parent to offspring

17. Define TRAIT Ways of looking, thinking, or being
Behavioural and physical features