Lesson 5- DNA Structures.

Question 1

How many chromosomes are there?

Answer 1

Most people have 46 chromosomes in each of the cells. You inherit 23 from your mother and 23 from your father.

Question 2

Define the term “genes.”

Answer 2

Short sections of DNA that code for a characteristic, such as eye colour, are called genes.

Question 3

Describe the structure of DNA.

Answer 3

DNA is made up of two strands. These strands are joined together by bases. The strands are then twisted together. This forms a shape known as a double helix. DNA is made of lots of small units called nucleotides, which are joined together. This means that DNA is a polymer.

Question 4

Define the term “nucleotides.”

Answer 4

Each nucleotide is made is made of a sugar (called deoxyribose), a phosphate group and a base. The two strands of DNA are held together by bonds between the bases.