Genes to Behavior Flashcards Preview

Genetics > Genes to Behavior > Flashcards

Flashcards in Genes to Behavior Deck (62)
Loading flashcards...
1
Q

Phenotype

A
  • determines specific characteristic
  • cannot be transmitted to following generations
  • influenced by genotype
  • determined by the properties of the proteins in its cells and the properties of the proteins are determined by its amino acids
2
Q

Genotype

A
  • genetic constitution of an individual organism

- it gives rise to phenotype (one way street) and next generation genotype

3
Q

Role of proteins

A
  • responsible for shape and structure of cells
  • form connecting tissues
  • control the many chemical reactions that a body needs to function : hormones, enzymes, antibodies
4
Q

Proteins are made up of amino acids. What are their properties?

A
  • 20 different types of amino acids

- properties of amino acids are determined by which amino acids are incorporated and in what order

5
Q

Role of genes

A

they encode amino acids recipes for a particular protein

-> sequence of DNA bases that determines trait

6
Q

Logic of Life

A

genes ( sequences of DNA bases) make up proteins ( sequence of amino acids) -> formation of bodies

7
Q

Classical Genetics

A

1 particles of inheritance (genes) passed on from parents to offspring determine phenotypic characteristics
2 genes often come in alternate forms (=alleles) -> gene codes for general characteristic colour and two allele for white and red
3 individuals have two copies of the same gene (one from each parent) -> diploid organisms

8
Q

How many chromosomes do human have?

A

23 pairs of chromosomes ; 22 pairs of autosomes and one pair of sex chromosome ( xx and xy)

9
Q

Nirtrogenous bases

A

adenine - thymine ( 2 hydrogen bonds)

cytosine - guanine ( 3 hydrogen bonds)

10
Q

Nucleoside

A

base + sugar

11
Q

Nucleotide

A

base + backbone

12
Q

Polynucleotide strand

A
  • meaning that each strand is made up of many small individual units called nuceotides
    antiparallel -> subunits run in opposite directions
    5’ = phosphate group
    to
    3’= OH group of sugar
13
Q

Codons

A

triplets of bases (64) which code for the 20 amino acids that make up enzymes and proteins

14
Q

central dogma

A

characteristics of phenotypes themselves are not transmitted to next generation
- genes affect properties of proteins but proteins do not affect properties of genes
-> flow of information is one way
example : huge muscles that developed throughout training are not transmitted to next generation ( training causes changes in phenotype and not in genotype)

15
Q

Silent carriers

A

genotypic characteristics of parents that are not observable in their own phenotypes but show up in their offsprings

16
Q
somatic cells ( most cells)
-> making more phenotypes
A
  • carry full copy of genome
  • make more genotypes through mitosis ( 2 cells are created that are identical to the first cell)
  • diploid

example : cells in skin and heart produce other cells in skin and heart but are not capable for producing neurons ornew human being

17
Q

Germ cells / Gameters

-> making more genotypes

A
  • carry only half of genome
  • make more genotypes through meiosis ( reduction from diploid to haploid cells)
  • haploid cells
    example : sperm in males and egg cells in females
18
Q

( Mutations ) - Substitution

A

Replacement of one nucleotide pair with another

19
Q

genetic code

A

mapping from particular codons in the mRNA to particular amino acids
code means for example whenever sequence of bases CGU is encountered on mRNA an arginine molecule A is added to protein chain

characteristics of genetic code

(1) universal and not random
(2) degenerates and regenerates
(3) not ambigious

20
Q

codon AUG

A

codes for methionine

-> initates process of translation

21
Q

codon UAG, UGA, UAA

A

indicate end of protein has been reached -> terminate translation

22
Q

significant properties of a codon

A

1 Error reading third base -> Transition
often makes no differnece to amino acid produced
= no difference ; synonymous substitution
-> interchange of two-ring-purines or one ring pyrimidine

2 Transversion - codons differing by just the first base tend to produce amino acids that are chemically similiar to each other
-> interchange of purine for pyrimidine

= robustness to errors

23
Q

chemical bonds -> within each strand

A

covalent bonds
extremely strong
-> if two strand are caused to split apart each strand will maintain its integrity

24
Q

chemical bonds -> between two strands

A

hydrogen bonds
weaker than covalent bonds
-> principle of base pairing

25
Q

Differential Gene Expression

A
  • difference between cells is not due to presence but due to expression ( all cells have same genome)
26
Q

Epigenetics

A

study of heritable phenotype changes that do not involve alterations in the DNA sequence.

1 on DNA Level example : methylation ; the addition of a methyl group, or a “chemical cap,” to part of the DNA molecule, which prevents certain genes from being expressed

2 On Histone Level
Methylation
Acetylation
Deacytelation

27
Q

polygenic gene (characteristic)

A

difference in phenotype is determined by multiple genes example is height

28
Q

single gene (characteristic)

A

differneces in phenotype determined by which allele the individual has at just ONE genetic locus (=spot on chromosome) -> mendelian disease

29
Q

backbone

A

sugar and phosphate

- run down on each side of the helix; chemically in opposite directions

30
Q

What is 5’ AGGTCCG 3’ ?

A

3’ TCCAGGC 5’

-> you can use one base sequence predict the counterpart

31
Q

Three major differences between DNA and RNA

A

1 RNA is a single-stranded molecule so no double helix
2 sugar in RNA is ribose and not deoxyribose -> has one more oxygen atom
3 RNA does not contain Thymine and instead Uracil

32
Q

Helicase

A

unnwinds the parental double helix

33
Q

Helicase

A

unwinds the parental double helix

34
Q

Primase

A

serves as starting point

  • > leading strand leads primase once at very beginning
  • > lagging strand : primase gives polymerase a starting point ( remember polymerase can only go 5’->3’ ) starting point enables polymerase to work backwards
35
Q

DNA Polymerase III

A

adds DNA nucleotides to the 3’ end of RNA primer

36
Q

Okazaki fragment

A

short section that arises at lagging strand during replication for supporting and enabling polymerase to add nucleotides

37
Q

DNA polymerase I

A

replaces primers with DNA nucleotides

38
Q

DNA ligase

A

combines Okazaki fragments

39
Q

RNA Splicing and Splicesomes

A

(Pre) RNA contains intron and exons
-> Spliceosomes remove introns to create mRNA -> breakting the junk (introns) segments down so that their bases can be reused so they stick together the ends of the good stuff (exons)

40
Q

Replication

A

DNA -> DNA

41
Q

Transcription

A

DNA -> RNA -> mRNA

42
Q

Translation

A

mRNA -> Protein

43
Q

What is the role of ribosomes in translation?

A

mRNA binds to ribosomes to initiate the process of translation
( ribosomes are a mix of proteins and rRNA )

44
Q

rRNA

A

doesnt contribute any genetic information to the process BUT it has binding sites that allow the incoming mRNA with tRNA

45
Q

tRNA

A

transfer or translation RNA -> translates from language of nucleotides into language of amino acids and proteins

-> binds to codon at ribosmose to form amino-acid-chain
(eg AUG -> protein Methionine) -> when triplet codon is detected the fitting anticodon is added by tRNA

46
Q

Redundancy

A

multiple codons code fr the same amino acid

47
Q

Silent mutation

A

codes for same amino acids due to redundancy -> nothing changes -> synonymous

48
Q

Missense mutation

A

changes amino acid (litte to huge effect) -> nonsynonymous

-> new base is added so that codon encodes for another (possibly) amino acid

49
Q

non-sense mutation

A

codon becomes stop codon -> causses translation to be terminated -> usually non functional protein

50
Q

Frameshift mutation

A
  • happens whenever the number of nucleotides inserted / deleted is not a multiple of 3
    result : extensive missense ending with nonsense & premature termination
51
Q

Histone

A
  • regulation of gene expression
52
Q

Histone acetylation

A

leads to uncoiling of chromatin structure which allows it to be accessed by transcriptional machinery for the expression of genes = euchromatin -> increases gene expression

53
Q

Histone deacetylation

A

leads to condensed or closed structure of the chromatin -> less transcription of genes =heterochromatin -> decreases gene expression

54
Q

Histone methylation

A

gene silencing
-> more permanent method of down-regulating transcription of genes

-> abnormal DNA methylation has been associated with cancer

55
Q

Histone phosphorylation

A

addition of phospahte group promotes loosening

-> increases gene expresiion

56
Q

DNA methylation

A

turns off genes -> methylation patterns are passed on during cell division

permanent gene silencing : eg cell differentiates in final form and needs to shut off genes coding for other cell types)

57
Q

What is simultanous Activation of Genes

A
  • result often in response to chemical signals from outside the cell ( genes with same control element are activated by same chemical signal)

hormone receptor complex : serves as a transcription activator

-> can be associated with cancer

58
Q

Linkage Studies

A

study within a family ( some have the phenotypic characteristic of interest and others dont)

59
Q

Association Studies

A

two samples of population

60
Q

expansion of triplet repeats such as CAG

A

associated with 14 disorders , including Huntingtons disease

61
Q

disjunction

A

a lack of correspondence and consistency

62
Q

non-disjunction

A

the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.