Questão 1
Questão
What are promoter regions of DNA?
Responda
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Gene regulatory elements that tell RNA polymerase to perform transcription.
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Gene regulatory elements that tell DNA polymerase to perform transcription.
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Gene regulatory elements that tell RNA polymerase to perform translation.
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Gene regulatory elements that tell DNA polymerase to perform translation.
Questão 2
Questão
Transcription factors bind to regulatory sequences and cause what?
Questão 3
Questão
What does the green question mark represent?
Responda
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Nucleosome
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Chromosome
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Telomere
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Promoter region
Questão 4
Questão
The green arrow is pointing to what?
Questão 5
Questão
The nucleosome is made up of what components?
Responda
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Histone octamer of H2A, H2B, H3 and H4.
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Core DNA
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Linker DNA
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Histone tetramer of H2A, H2B, H3 and H4.
Questão 6
Questão
SRY is a transcription factor on the Y chromosome. It's absence/mutation leads to...?
Responda
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Absence of the male phenotype, leading to production of a female phenotype.
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Absence of the female phenotype, leading to production of the male phenotype.
Questão 7
Questão
The Y gene of the XY male genotype is gene-poor. What are two dosage compensation mechanisms that could help to equal gene expression levels in both males and females.
Responda
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Upregulation of transcription of the X male chromosome
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Inactivation of one of the X female chromosomes
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Addition of an extra X chromosome in the male XY genotype
Questão 8
Questão
Epigenetics produces multiple phenotypes from the same genotype.
Questão 9
Questão
Diploid cells have a single copy of an allele.
Questão 10
Questão
Autosomal conditions are genetic conditions that occur on non-sex chromosomes.
Questão 11
Questão
An X-linked condition will only affect the phenotype of a female if the copies of the allele on each X chromosomes are abnormal.
Questão 12
Questão
Achondroplasia (dwarfism) is what type of condition?
Responda
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Autosomal dominant
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Autosomal recessive
Questão 13
Questão
Albinism is what type of condition?
Responda
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Autosomal recessive
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Autosomal dominant
Questão 14
Questão
How might a child have achondroplasia despite the parents not having it?
Questão 15
Questão
How can two parents that have albinism have a child without albinism?
Responda
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Albinism is autosomal recessive. This means that any child born to parents who both have albinism should also have albinism as there are no dominant traits in the parents as their genotypes are both homozygous recessive. The reason for the absence of albinism is because the mutated copies in the parents could differ in that the fathers two copies could inhibit a different enzyme in the metabolic pathway that leads to lack of pigment than the mothers. The child will inherit one copy from the father and one copy from the mother and therefore only 50% of each originally fully mutated pathway is inhibited and thus may still be able to produce sufficient melanin.
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Albinism is autosomal dominant. This means that any child born to parents who both have albinism should also have albinism as there are no dominant traits in the parents as their genotypes are both homozygous dominant. The reason for the absence of albinism is because the mutated copies in the parents could differ in that the fathers two copies could inhibit a different enzyme in the metabolic pathway that leads to lack of pigment than the mothers. The child will inherit one copy from the father and one copy from the mother and therefore only 50% of each originally fully mutated pathway is inhibited and thus may still be able to produce sufficient melanin.
Questão 16
Questão
Haemophilia results in blood clotting problems due to factor 7 deficiency.
Questão 17
Questão
Females are more likely to suffer from haemophilia
Questão 18
Questão
Phenylketonuria is a disorder resulting from the production of phenylketones due to mutation in what enzyme?
Questão 19
Questão
What are some causes of variation?
Questão 20
Questão
How many pairs of autosomal chromosomes do most humans have?
Questão 21
Questão
Mitosis is important for what?
Responda
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Growth
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Repair
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Tumour growth
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Spermatogenesis
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Oogenesis
Questão 22
Questão
What is crossing over?
Questão 23
Questão
What is independent assortment?
Questão 24
Questão
When does independent assortment occur?
Responda
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First meiotic division
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Second meiotic division
Questão 25
Questão
Chromosomal non-disjunction describes the failure of homologous chromosomes to seperate in the first or second division in meiosis or during mitosis.
Questão 26
Questão
Chromosomal non-disjunction can lead to trisomy of sex chromosomes.
Questão 27
Questão
The following picture shows the process of meiosis in males
Questão 28
Questão
The following picture shows chromosomal non-disjunction of the...
Responda
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First division
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Second division
Questão 29
Questão
The following picture shows chromosomal non-disjunction during female meiosis.
Questão 30
Questão
Meiotic non-disjunction occurs pre-embryonically and therefore all cells are effected.
Questão 31
Questão
Mitotic non-disjunction occurs during embryonic division so there may be a mix of normal and abnormal cells, resulting in an abnormal conceptus.
Questão 32
Questão
How does trisomy 21 (aka Down's) occur?
Responda
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One copy of the mother's C21 translocates to C14. Upon fertilisation, the future child will have inherited two copies from the mother (due to the translocated C21 to C14 as well as the normal C21 copy) and a copy from the father, making 3 copies of C21.
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The mother is a carrier of three C21 copies which leads to the child inheriting two copies of C21 from the mother and one from the father.
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C14 changes into C21 upon fertilisation, therefore two copies are inherited from mother/father and one other copy from the father/mother.
Questão 33
Questão
Mutations are frequently due to...
Responda
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Copying errors during DNA replication
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Spontaneous depurination
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Background ionising radiation
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Chromosomal non-disjunction
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Splicing errors
Questão 34
Questão
A transcriptional mutation commonly affects the promoter region of a gene, therefore promotion to initiate transcription does not occur and thus a protein is not produced.
Questão 35
Questão
A splice site mutation (deleted/creation of splice site) does not introduce introns into the mature mRNA transcript.
Questão 36
Questão
Common gene mutations are indicated in certain cancers.
Questão 37
Questão
What is the function of the mismatch repair machinery?
Responda
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The mismatch repair machinery helps to repair slippaged DNA (insertion/deletions) that escapes proofreading
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The mismatch repair machinery helps to destroy cancer cells
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The mismatch repair machinery helps to repair incorrectly paired DNA strands
Questão 38
Questão
Sickle cell is caused by a substitution of hydrophilic valine for hydrophobic glutamate (GAG -> GTG)
Questão 39
Questão
Cystic fibrosis is caused by deletion of a codon coding for a phenylalanine residue of the CFTR channel protein.
Questão 40
Questão
PCR are repeated cycles of...?
Responda
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Primer, Polymerase, Denaturation.
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Polymerase, Primer, Denaturation.
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Denaturation, Polymerase, Primer.