Gene Function Analysis in eukaryotes

Question 1

What did Mendel discover

Answer 1

Genes

Question 2

What are the advantages of using pea plants for genetic analysis

Answer 2

hermaphroditic, lots of natural variation, reproduce by self fertilisation

Question 3

Describe the haploidy/diploidy of parents and gametes

Answer 3

Parents are diploid, gametes are haploid

Question 4

What was Mendel’s first law

Answer 4

Principle of segregation, alleles of genes segregate during gamete formation

Question 5

What as Mendel’s second law?

Answer 5

Principle of independent assortment, genes controlling different characters assort into gametes independently

Question 6

Describe Incomplete Dominance

Answer 6

heterozygous phenotype is intermediate between 2 homozygous parental phenotypes

Question 7

Example of incomplete dominance

Answer 7

Snapdragon flower, carnation flower

Question 8

Describe co-dominance

Answer 8

simultaneous expression of two phenotypes

Question 9

Example of co-dominance

Answer 9

blood groups

Question 10

How are genes located on the same chromosome described

Answer 10

linked

Question 11

How can non-parental combinations of alleles occur?

Answer 11

crossovers between chromosomes during meiosis

Question 12

What affects the rate of recombination

Answer 12

genetic distance between genes on the same chromosome

Question 13

If genes are close together on the same gene how common is recombination

Answer 13

very uncommon

Question 14

How are genetic pathways analysed?

Answer 14

Complementation tests

Question 15

Describe loss of function mutations?

Answer 15

recessive and reduce gene function

Question 16

What do complementation tests tell us?

Answer 16

Whether two independent recessive mutations with similar phenotypes lie in the same or different genes

Question 17

Where do complementing mutations lie

Answer 17

different genes

Question 18

where do non-complementing mutations lie

Answer 18

same gene

Question 19

What can induce mutations (non-natural)?

Answer 19

X-rays, UV, chemical mutagens, and DNA mutagens

Question 20

Name two alkylating agents

Answer 20

EMS and ENU

Question 21

How do alkylating agents work

Answer 21

covalently modify DNA

Question 22

Describe the effect of alkylating agents on DNA

Answer 22

Modify guanine so its unable to bond with cytosine

Question 23

What do alkylating agents cause in non germline cells

Answer 23

tumours

Question 24

How do UV, X-rays and gamma rays cause mutations in DNA

Answer 24

induce breaks in DNA backbone, knock off electrons and break covalent bonds

Question 25

Describe the effect of UV on DNA

Answer 25

causes thymine to form covalent bonds with thymine, causes small deletions of insertions of nucleotides

Question 26

Describe genome engineering

Answer 26

targets specific genes, introduces precise changes in specific DNA sequences

Question 27

What is transgenesis?

Answer 27

Gene addition

Question 28

What is knockout

Answer 28

Complete loss of gene function

Question 29

What does gene replacement/knockout rely upon?

Answer 29

homologous recombination

Question 30

What is the function of enzymes in genome engineering

Answer 30

recombine foreign DNA into genomic DNA

Question 31

Describe zinc finger nucleases

Answer 31

Proteins that bind to specific parts of DNA

Question 32

What is the function of ZFNs?

Answer 32

create small deletions, insertions or substitutions at site

Question 33

Describe CRISPR/Cas9

Answer 33

bacterial immunity system against infectious bacterial virus genomes

Question 34

How does CRISPR/cas9 work

Answer 34

uses RNA to guide nuclease to cleave a specific DNA site

Question 35

Advantages of homologous recombination

Answer 35

very precise genome alterations like deletions, insertions and rearrangements, low frequency off target effects

Question 36

Disadvantages of homologous recombination

Answer 36

slow

Question 37

Which technique is the most precise for genome alterations

Answer 37

homologous recombination

Question 38

What are complementing mutations?

Answer 38

when different homozygous recessive mutations give the same phenotype