Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GEN > GEN1 - Key Terms and Concepts in Genetics and Genomics > Flashcards

GEN1 - Key Terms and Concepts in Genetics and Genomics Flashcards

1
Q

Define genetics.

A

Study of single or multiple genes and how they affect characteristics (e.g. phenotype).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define genomics.

A

Studying of all genetic information, not solely the genes. Includes non coding regions, regulatory regions, repetitive repeats etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are genes?

A

Considered the units of hereditary. Sections of DNA coding for proteins or functional RNA molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What chromosomes are found in a human cell?

A

Nuclear chromosome - main genome consisting of 23 pairs.

Mitochondrial chromosome - additional smaller circular chromosome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What word describes a location on a chromosome?

A

Loci.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Discuss process occurring from genes to proteins.

A

Genes undergo transcription to form mRNA. This is dependent on promoter regions, transcription factors and gene accessibility. Mature mRNA undergoes splicing and processing. The mature mRNA is then translated into protein by membrane bound or free ribosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give five types of functional RNA.

A 
rRNA
tRNA
miRNA
ncRNA
siRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define haploid and diploid with examples.

A

Haploid - cells with half the genetic information - gametes.

Diploid - cells with full genetic information - somatic cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are gametes haploid?

A

Ensures that genetic information within somatic cells remains at a constant level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How much of the entire genome codes for genes/proteins?

A

20,000 genes present within the genome. Approx 25% of whole genome is for genes.

However, only 2% of the whole genome is for proteins/RNA - these are the exons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define the transcriptome and if it varies between cells.

A

Refers to RNA within cells - some definitions include both protein and non protein coding RNA.

Varies between cells as differing levels of gene expression are apparent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define the exome and if it varies between cells.

A

Includes all exons within the genome. Does not vary between cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define the proteome and if it varies between cells.

A

Refers to all the proteins expressed within a cel. Varies between cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What was Mendels key discovery?

A

Genes as the units of hereditary.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What was discovered as a result of Mendels discovery?

A

DNA, genome, link to diseases/traits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define genotype and phenotype.

A

Genotype - genetic makeup.

Phenotype - observable feature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define heterozygous and homozygous.

A

Heterozygous - contains two different versions of a gene.

Homozygous - contains two same versions of a gene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define recessive and dominant.

A

Recessive - two copies required for phenotype observation.

Dominant - one copy required for phenotype observation ONLY.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Give two types of homozygosity.

A

Recessive or dominant. E.g. aa or AA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is needed to observe Mendelian ratios in an experiment?

A

Large sample size - ratios can only be observed with enough offspring.

21
Q

What is sickle cell disease?

A

Autosomal recessive condition causing sickling of haemoglobin. Reduces oxygen delivery. Associated with anaemia. Can block blood vessels.

22
Q

Define and differentiate forward and reverse genetics.

A

Forward genetics - observing phenotypes to deduce the underlying genotype.

Reverse genetics - altering genotype (expression of gene or genetic modification) and observing the phenotype.

23
Q

Give differences between normal and sick cell patients at clinical, cellular and molecular level.

A

Clinical - normal have no symptoms vs affected susceptible to infections/anaemia.
Cellular - normal have disc shaped RBC vs affected have sickle shaped RBC.
Molecular - normal have normal Hb vs affected have aggregated Hb.

24
Q

What protein chains are within Hb?

A

Two alpha protein chains.

Two beta protein chains.

25
Q

What is observed during electrophoresis of normal vs sickle Hb and why?

A

Differing migration speeds through gel. Hb-S is more positive therefore migrates faster towards the anode. Hb-A is more negative so migrates slower towards the anode.

26
Q

What type of haemoglobin is found in sickle cell trait individuals?

A

Both normal and sickle haemoglobin found in patients with sickle cell trait.

27
Q

What changes are present within sickle haemoglobin and how were they discovered?

A

Peptide sequencing revealed change from glutamine to valine at 6th amino acid position in beta globin protein chain.

Nucleotide sequencing revealed change from GAG to GTG causing the amino acid change.

28
Q

Are sickle cell trait individuals (a)symptomatic? Does this change?

A

Generally asymptomatic. Hypoxic conditions can cause aggregation of Hb-S present which cannot be overcome by HbA.

29
Q

Discuss link between sickle cell disease and malaria.

A

Sickle cell disease has high incidence in malaria prone regions - SCD provides increased resistance to malaria.

30
Q

What are the three classifications of genetic diseases? Describe each.

A

Monogenic - genetic conditions caused by single gene mutations and show Mendelian inheritance.

Polygenic - genetic conditions caused by multiple gene mutations so do not show Mendelian inheritance.

Acquired - mutations arise that are not present in parents, causing genetic disease.

31
Q

What are the five classes of monogenic diseases? Describe each.

A

Autosomal recessive - two copies needed on either autosome pair.
Autosomal dominant - one copy needed on either autosome pair.
X-linked recessive - two allele needed in females but only one in males (affects males more).
X-linked dominant - one allele needed.
Mitochondrial - passed by mother but can affect both genders.

32
Q

How can polygenic diseases be studied?

A

Use of genome wide association studies.

33
Q

Give examples of polygenic diseases.

A

Heart disease. Diabetes. Obesity.

34
Q

What factors increased chance of acquired genetic diseases?

A

Exposure to mutagens. Viral infections.

35
Q

What is the effect of mutations arising in somatic cells and germ cells, on acquired genetic diseases?

A

Mutation in somatic cell - common cause of cancer - not passed onto offspring.

Mutation in germ cell - can be passed onto offspring - can result in de novo mutations.

36
Q

Aside from genotype, what two factors largely affect phenotype?

A

Environmental influences.

Epigenetic changes.

37
Q

Give three classes of agents that can cause environmental influences on the phenotype. Give example for each.

A

Chemical agent - pollutants.
Physical agents - UV light.
Biological agent - viral infections.

38
Q

What is the difference between minor and major phenotypic changes?

A

Minor phenotypic change - benign mole formation.

Major phenotypic change - cancerous tumour formation.

39
Q

Give examples of environmental influences that directly alter gene expression.

A 
Temperature
Pressure
Irradiation
Oxygen levels
Diet 
Toxins
40
Q

When is a disease described as multi factorial?

A

Various genes and environmental influences affect the disease onset, severity, risk etc.

41
Q

Define the epigenome.

A

Complete set of epigenomic tags on the genome,

42
Q

Does the epigenome alter any of the following: transcriptome, genome, phenotype, exome, proteome.

A

Transcriptome - yes as genes undergoing transcription are changed.
Proteome - yes as transcriptome changes affect proteome.
Phenotype - yes as different proteins may have differing phenotypic outcomes.
Genome and exome - unaffected.

43
Q

Are epigenetic changes permanent/can be passed on?

A

Not permanent however can be passed on via mitosis and meiosis

44
Q

Discuss overview of nuclear transfer.

A

Somatic cell taken from parent. Egg cell taken from donor mother and enucleated, removing all genetic information. Somatic cell and enculeated egg cell are shocked to stimulate fertilisation and cell division.

45
Q

Define epimutations.

A

Mutations that occur that change the epigenome.

46
Q

Define consanguinity.

A

Marriage between individuals with the same ancestor.

47
Q

What is the degree of consanguinity?

A

The extent of relationship between the two individuals in question. Used to determine the average DNA shared between the two.

48
Q

Which familial relationship has the most DNA shares?

A

Identical twins/clones.

GEN (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions