Topic 3 - Genetics

Question 1

What does sexual reproduction produce?

Answer 1

Genetically different cells

Question 2

What type of cell is a gamete?

Answer 2

Haploid cell

Question 3

What are the two gametes?

Answer 3

• Sperm

- Egg

Question 4

By what process are gametes produced?

Answer 4

Meiosis

Question 5

Briefly describe the process of meiosis:

Answer 5

• DNA duplicates
• One chromosome from each parent pairs with another
• Cells divide
• Chromosomes line up again
• Cells divide, forming 4 haploid daughter cells

Question 6

What type of cell division happens in asexual reproduction?

Answer 6

Mitosis

Question 7

What are the advantages of sexual reproduction?

Answer 7

• Genetic variation

- Natural selection

Question 8

What are the disadvantages of sexual reproduction?

Answer 8

• Takes more time and energy

- Two parents needed

Question 9

What are the advantages of asexual reproduction?

Answer 9

• Produces lots of offspring very quickly

- Only one parent is needed

Question 10

What are the disadvantages of asexual reproduction?

Answer 10

• No genetic reproduction

- High chance of carrying diseases

Question 11

What is a DNA strand?

Answer 11

A polymer made up of lots of repeating units called nucleotides

Question 12

What are the 4 DNA bases?

Answer 12

• Adenine
• Thymine
• Cytosine
• Guanine

Question 13

What is DNA stored as?

Answer 13

Chromosomes

Question 14

What is the name given to a section of a chromosome that codes for a protein?

Answer 14

Gene

Question 15

How are proteins made?

Answer 15

By reading the code in DNA

Question 16

What is a protein made up of?

Answer 16

A string of amino acids, in a specific order that can fold up into a particular shape

Question 17

What is a non-coding region of DNA?

Answer 17

An area of the DNA that doesn’t code for an amino acid

Question 18

What is a genetic mutation?

Answer 18

When part of a gene changes, meaning that the protein cannot fold up, or the amino acids are in the wrong order

Question 19

Describe transcription in protein synthesis:

Answer 19

• RNA Polymerase binds to the non-coding region of a gene
• The two DNA strands unzip, and the RNA polymerase moves along the strand
• It makes mRNA by using the strand as a template
• Once made, the mRNA moves out and goes to a ribosome

Question 20

Describe translation in protein synthesis:

Answer 20

• Amino acids are brought to the ribosome by tRNA
• The mRNA shows the order for the proteins to be fitted together in
• Amino acids are joined together in the correct order, forming a polypeptide/protein

Question 21

What did Mendel do with pea plants?

Answer 21

• Bred a tall and short pea plant, which produced all tall offspring
• Bred these offspring together, and some were tall, so were short

Question 22

What did Mendel’s experiments show?

Answer 22

The height characteristic was determined by separately inherited ‘hereditary units’ (Tt)

Question 23

What are alleles?

Answer 23

Different variations of the same gene

Question 24

What are the two types of allele?

Answer 24

• Dominant

- Recessive

Question 25

What is a phenotype?

Answer 25

Physical characteristic

Question 26

What is a genotype?

Answer 26

Combination of alleles

Question 27

What are the three ways to show inheritance?

Answer 27

- Genetic diagram - Punnett square - Family Pedigree

Question 28

What is the notation in a family pedigree diagram?

Answer 28

- Cricle = Female - Square = Male - Coloured = Affected - Half-Coloured = Carrier - Empty = Unaffected

Question 29

What is a sex-linked genetic disorder?

Answer 29

A disorder caused by a faulty allele on a sex chromosome

Question 30

Name 2 sex-linked genetic disorders:

Answer 30

- Colour blindness | - Haemophilia

Question 31

Why are males more likely to inherit a sex-linked disorder?

Answer 31

Because they only have 1 X chromosome, so cannot compensate for it as the Y chromosome is a lot shorter

Question 32

What are the 4 blood groups

Answer 32

- A - B - AB - O

Question 33

Which two alleles for blood group are co-dominant?

Answer 33

A and B

Question 34

What is variation?

Answer 34

Differences between organisms of the same species

Question 35

What was the human genome project?

Answer 35

A project to map every single human gene

Question 36

How many human genes did the Human Genome project map?

Answer 36

20,500

Question 37

How long did the Human Genome Project last?

Answer 37

13 years - 1990 until 2013

Question 38

What are the medical applications for the HGP?

Answer 38

- Prediction of diseases - Prevention of diseases - Development of medicines - Testing for gentic disorders