Genetics

Question 1

What does meiosis produce?

Answer 1

4 genetically different haploid gametes

Question 2

How many divisions are there in meiosis?

Answer 2

2

Question 3

What are the stages of meiosis?

Answer 3

1. Dna replicates
2. Cell divides
3. Chromosomes line up in pairs in centre
4. Pairs then pulled apart
5. Cell divides again
6. 4 haploid daughter cells made

Question 4

Where is genetic info found?

Answer 4

In the nucleus of every cell

Question 5

What is DNA?

Answer 5

Very tightly wound up chemical

Question 6

What is a gene?

Answer 6

A short section of a chromosome which codes for a specific protein

Question 7

What are the complementary base pairs in a double helix?

Answer 7

Adenine Thymine

Guanine Cytosine

Question 8

What are the complementary base pairs joined together by?

Answer 8

Weak hydrogen bonds

Question 9

What are the 2 main strands of a double helix called?

Answer 9

Backbones

Question 10

What are the advantages and disadvantages of sexual reproduction?

Answer 10

Adv:
- variation in the population

Disadv:
- need to find a mate

Question 11

What are the advantages and disadvantages of asexual reproduction?

Answer 11

Advs:

• don’t need to find a mate
• rapid reproduction cycle

Disadv:
- no variation in the population

Question 12

What is the experiment for dna extraction?

Answer 12

1. Grind small piece of fruit opening cells, gently causing no damage to DNA
2. 1/4 fill boiling tube with fruit paste
3. Fill to 3/4 full with salt and detergent
4. Put in hot water bath for 10 mins
5. Pour off resulting solution into test tube
6. Carefully run ice cold ethanol down side

Question 13

What does the salt and detergent do to the fruit paste?

Answer 13

The salt makes the dna stick

The detergent breaks down the cell membrane

Question 14

What does the ice cold ethanol do to the dna?

Answer 14

Separates dna

Question 15

What is an allele?

Answer 15

Different versions of the same gene

Question 16

What is a genotype?

Answer 16

The alleles that make up a given feature

Eg. (gg/GG/Gg)

Question 17

What is a phenotype?

Answer 17

The characteristics we see

Question 18

What does homozygous mean?

Answer 18

2 alleles that are the same for a given feature

Question 19

What does heterozygous mean?

Answer 19

2 alleles that are different for a given feature

Question 20

What does dominant mean?

Answer 20

The allele which will be shown in the organisms features (GG/Gg)

Question 21

What does recessive mean?

Answer 21

Two required for the characteristic to show (gg)

Question 22

What is the genetic diagram called using alleles?

Answer 22

Punnet square

Question 23

What pair of chromosomes determine someone’s gender?

Answer 23

The 23rd

Question 24

What is the chromosome pair for females?

Answer 24

XX

Question 25

What is the chromosome pair for males?

Answer 25

XY

Question 26

Meiosis makes 4 sperm cells. How many are X and how many are Y?

Answer 26

50% X

50% Y

Question 27

Meiosis makes 4 egg cells. How many are X?

Answer 27

All of them

Question 28

What does a pedigree chart tell you?

Answer 28

How genotypes and phenotypes are inherited in a family

Question 29

What is a genome?

Answer 29

All of the dna in an organism

Question 30

What was the human genome project?

Answer 30

A project where scientists sequenced all of the bases in the human genome

Question 31

What are the benefits of the human genome project?

Answer 31

Help identify personalised medicines

Identify genes that someone has that make them more likely to develop a cause disease