SB3c DNA

Question 1

Recall where DNA is found in a eukaryotic

cell.

Answer 1

It is found in the nucleus.

Question 2

Name the bases in DNA.

Answer 2

Adenine, thymine, cytosine and guanine are the four nucleotides found in DNA.

Question 3

Recall the pairing of bases in DNA.

Answer 3

Adenine and thymine

Cytosine and guanine

Question 4

Describe how DNA strands are held together.

Answer 4

Each strand has a backbone of sugar, and phosphate groups. It is held by weak hydrogen bonds.

Question 5

Describe the overall structure of DNA.

Answer 5

Its structure is described as a double-stranded helix held together by complementary base pairs. The basic units of DNA are nucleotides. These nucleotides consist of a deoxyribose sugar, phosphate and base.

Question 6

Describe how DNA can be extracted from fruit.

Answer 6

Make sure you remove the fruit skins as they are mostly dead and don’t contain DNA. The fruit needs to be broken up so the extraction solution can get to the cells. In this step the detergent breaks down the cell membranes so the DNA can be released. The salt removes proteins that are bound to the DNA.