Lecture 1

Question 1

Homolog

Answer 1

-Genes share a common ancestral DNA sequence

Question 2

Ortholog

Answer 2

• Genes found in different species that have evolved from a common species via speciation
• often retain same function

Question 3

Paralog

Answer 3

• genes produced by gene duplication as the main event

- develop new function in each species

Question 4

CpG Islands

Answer 4

• DNA segment> 200bp
• Expected GC > 60% but it is 50%
• found near promotor genes (mutation hotspot)

Question 5

How do Somatic cells differ from Germ Cells

Answer 5

• do not share same amount of genetic material/same sequences
• SOmatic = many nuclie
• Somatic cells of immune system have unique gene material due to Gene-rearrangement

Question 6

Template vs Non-Template Synthesis

Answer 6

Template synthesis:

• DNA serves as template
• produces: Proteins/Enzymes

Non-Template Synthesis:

• CHO and Lipids
• enzymes make them

Question 7

Genome

Answer 7

-all the genetic material of a cell

Question 8

Genetics

Answer 8

-Study of individual genes and their inheritance + variability

Question 9

Genomics

Answer 9

-study of entire genome and gene interactions

Question 10

Sense strand

Answer 10

-the mRNA derived from transcription will read like the sense strand

Question 11

Anti-Sense Strand

Answer 11

-used as a template for mRNA synthesis

Question 12

How does RNA structure differ from DNA

Answer 12

• Uracil instead of Thymidine
• Extra -OH on 2nd C of the Ribose sugar
• Single stranded

Question 13

Basic DNA structure

Answer 13

-db Helix (146 NT Pairs) wrap around 8 Histones -> Nucleosomes (chromatin) –> wrap in 30nm solenoid chromatin –> condenses into greater structure

Question 14

Scaffold in DNA structure

Answer 14

Topiomerase II:
- is the scaffold region which Solenoid DNA is organised on

SAR (scaffold attachment region)

• untranscribed
• Top 2 binds to it

Question 15

Chromatin vs Chromosome

Answer 15

Chromatin:
-unwound, uncondensed DNA material of INTERPHASE (G1,S,G2)

Chromosome:
-wound, tightly coiled DNA of DIVIDING CELLS

Question 16

Gene

Answer 16

-unit of Inheritance (part of the DNA or RNA)

Question 17

Locus

Answer 17

-location of a given gene on a chromosome

Question 18

Allelle

Answer 18

-gene variant at a given locus

Question 19

Wild Type Allele

Answer 19

-most frequent variant of a given gene in nature

Question 20

Genotype

Answer 20

-genetic composition for an individual or a locus

Question 21

Homozygote

Answer 21

-identical alleles at the same loci of the chromosome pair

Question 22

Heterozygote

Answer 22

-different alleles at the same loci of the chromosome pair

Question 23

Hemizygote

Answer 23

-only on single copy of the gene

Question 24

Ploidy

Answer 24

-Ploidy refers to the number of Homologous chromosomes in a cell

Haploid:
-cell contains one set of chromosomes

Diploid:
-cell contains 2 sets of chromosomes

Question 25

Dominant Allele

Answer 25

-a gene variant that phenotypically always results in a given character

Question 26

Recessive Allele

Answer 26

-an allele which manifests phenotypically in Homo/Hemizygotes

Question 27

How many diseases follow Mendelian Inheritance

Answer 27

>6000

Question 28

Mendelian Genetic laws

Answer 28

1. Law of Segregation: - during gamete formation - members of allele pairs separate so that each gamete only recieves one allele for a corresponding gene 2. Law of Independent Assortment: - genes for different traits assort indepedently of each other during gamete formation 3. Law of Dominance: - dominant allelles will mask recessive alleles in hetereozygotes

Question 29

Mitochondrial DNA

Answer 29

- maternal lineage (as sperm does not contribute to cytoplasm) - 37 genes - NO Introns/Histones/poor repair mechanisms - high rate of mutation + non-Mendilian pattern of inheritance

Question 30

What does Mitochondrial DNA code for

Answer 30

-code for TRP (by TGA - instead of it being stop codon)

Question 31

Types of Repeating Units

Answer 31

1) LINE (long interspersed elements) 2) SINE (short interspersed elements) 3) DNA Transposons 4) LTR Transposons (Retrovirus like elements)

Question 32

Autonomous vs Non-Autonomous Repeatin Units

Answer 32

Autonomous - encode for their own protein | Non-Autonomous - do not encode for their own but use Autonomous proteins

Question 33

LINE

Answer 33

- autonomous - 20% of total genome - encode for Reverse Transcriptase

Question 34

SINE

Answer 34

- non-autonomous - 13% of genome - uses RT from LINE

Question 35

LTR Transposons

Answer 35

- both - 8% of total genome - at each of their ends -> Long Terminal Repeats

Question 36

DNA Transposons

Answer 36

- both - Class 2 -> 3% of genome - encode Transposase (have short inverted repeats on their ends)

Question 37

Class 2 DNA Transposons

Answer 37

-Cut and PAste

Question 38

Class 1 Retrotransposons

Answer 38

-Copy and Paste

Question 39

TATA BOX

Answer 39

- DNA sequence found in many Gene promotor's - serve as a binding site for - TF or Histones - TF2 -> RNA Polymerase II --> start transcription

Question 40

5'UTR

Answer 40

- aka= Leader Sequence | - region of mRNA directly above inititiation codon

Question 41

Imp of 5'UTr

Answer 41

- reg of translation - may form complex secondary structures - or translate into protein product that then regulates translation

Question 42

Euchromatin vs Hetereochromatin

Answer 42

- DNA in nuclear exists in 2 forms reflecting the cellular activity state - Hetereochromatin: dark, irreglar patches (in not active/low active cells) - Euchromatin: dispersed + not readily stained (in active cells)