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Flashcards in DNA Deck (18):
1

Explain the structure of DNA

DNA is made out of 2 strands called backbones that are coiled together to form a spiral called a double helix.
The 2 strands are joined together by complementary base pairs joined together with weak hydrogen bonds

2

Name the base pairs

Ademine thymine
Guadamine cytosine

3

What are the benefits of the human genome project?

• Identify genes that someone has that make them more likely to develop a cause disease.
• Help identify personalised medicines which would be most successful in treating each person specifically based on their DNA

4

What are the steps to extract DNA from fruit? (practical)

Gently crush fruit with salt and soap (detergent)
Filter
Add ice cold alcohol

5

Why do you crush the fruit gently and apply salt and soap (detergent)- DNA practical

Crush - opens up cells
Gently - doesn’t damage DNA
Salt - makes DNA stick together
Soap - breaks open cell

6

Why do you use a filter - DNA practical

Remove bits of cell

7

Why do you ice cold alcohol - DNA practical

Seperates out DNA from solution

8

What does homozygous mean?

2 of the same allele

9

What does recessive mean?

This allele has no effect if the dominant allele is present

10

What is a zygote?

It is formed when 2 gametes (sex cells) meet

11

What does dominant mean?

The allele which is stronger

12

What is heterozygous?

2 alleles that are different

13

What is the phenotype?

The physical characteristics that we see

14

What is the genotype?

The 2 alleles you have for a gene

15

What is a gene?

A section of a chromosone which controls a characteristic

16

What is the genotype for homozygous dominant?

BB - 2 capital letters

17

What is the genotype for heterozygous?

Bb - 1 capital letter 1 lower case letter

18

What is the genotype for homozygous recessive?

bb - 2 lower case letters