Brainscape's Knowledge GenomeTM

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


See full index

A Level Biology > gene expression > Flashcards

gene expression Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the role of transcription and translation in gene expression?

A

They regulate the metabolic activities of cells, enabling specialization by expressing specific genes to form tissues and organs.

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

What are totipotent stem cells and where are they found?

A

Totipotent stem cells can divide and produce any type of body cell and are present in the early divisions of a mammalian embryo.

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

What is a pluripotent stem cell and how is it different from a multipotent stem cell?

A

Pluripotent stem cells can develop into most body cell types and divide in unlimited numbers, whereas multipotent stem cells can only develop into a limited range of cell types.

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

What is the significance of iPS cells in medicine?

A

Induced pluripotent stem cells can be created from somatic cells using transcription factors, offering potential for personalized medicine without using embryos.

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

What is a transcription factor and its role in gene expression?

A

A transcription factor is a protein that binds to specific DNA sequences to regulate the transcription of genes, acting as an activator or repressor.

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

How does oestrogen affect gene transcription?

A

Oestrogen binds to the ERα receptor in the cytoplasm, allowing it to enter the nucleus and stimulate transcription of target genes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is RNA interference (RNAi) and its components?

A

RNAi inhibits translation of mRNA using molecules like siRNA and miRNA, which bind to target mRNA and block or degrade it.

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

How can environmental factors influence gene expression epigenetically?

A

Environmental changes can increase DNA methylation or decrease histone acetylation, condensing chromatin and inhibiting transcription.

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

What are the two main types of tumours and how do they differ?

A

Benign tumours grow slowly and do not spread, while malignant tumours grow rapidly, invade surrounding tissues, and can metastasize.

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

What is the role of tumour suppressor genes in cancer prevention?

A

They inhibit cell division, and mutations or hypermethylation can inactivate them, leading to uncontrolled cell growth.

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

How does PCR amplify DNA?

A

PCR amplifies DNA by denaturation (95°C), annealing of primers (55°C), and synthesis by DNA polymerase (70°C), repeated in cycles.

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

What is recombinant DNA technology?

A

A technique to transfer DNA between organisms, producing transgenic organisms capable of expressing the transferred genes.

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

How are DNA fragments separated in electrophoresis?

A

DNA fragments are separated based on size by applying an electric field in a gel; smaller fragments move further towards the positive electrode.

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

What are VNTRs and how are they used in genetic fingerprinting?

A

VNTRs are variable number tandem repeats of non-coding DNA. Their unique patterns are used for identifying individuals.

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

What are the ethical concerns of using recombinant DNA technology?

A

Concerns include monoculture, environmental impact, corporate dominance, and potential misuse for ‘designer babies.’

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

What are the types of gene mutations and examples?

A

Substitution (e.g., ATG.CCT to ATT.CCT), Deletion (e.g., ATG.CCT to ATC.CT), Addition (e.g., ATG.CCT to ATG.ACC.T), Duplication, Inversion, and Translocation.

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

How do mutagenic agents increase the mutation rate?

A

Base analogs substitute bases (e.g., 5-bromouracil for thymine), alkylating agents change base pairing, and UV radiation alters DNA structure.

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

Why do additions, duplications, and deletions often have severe effects on proteins?

A

They cause frameshift mutations, altering downstream codons and the amino acid sequence.

20
Q

What is the difference between coding and non-coding DNA in terms of translation?

A

Most of a cell’s DNA is non-coding and not translated, serving regulatory or structural functions instead.

21
Q

What are the roles of promoter and terminator regions in gene expression?

A

Promoter regions signal RNA polymerase where to start transcription; terminator regions signal where to stop.

22
Q

What are the differences between siRNA and miRNA in RNA interference?

A

siRNA binds fully to target mRNA and degrades it, while miRNA binds partially, blocking translation and storing mRNA.

23
Q

What is the role of DNA methylation in epigenetics?

A

Increased methylation inhibits gene expression by making DNA less accessible for transcription.

24
Q

What is the significance of acetylation in epigenetic regulation?

A

Decreased acetylation condenses chromatin, preventing transcription.

25
Q

What are proto-oncogenes and how do they contribute to cancer when mutated?

A

Proto-oncogenes stimulate normal cell division, but mutations or hypomethylation can turn them into oncogenes, leading to uncontrolled division.

26
Q

How can genome projects aid vaccine production?

A

Sequencing simpler organisms’ genomes helps identify their proteomes, including antigens for vaccines.

27
Q

What is the role of restriction endonucleases in recombinant DNA technology?

A

They cut DNA at specific palindromic sequences, creating sticky ends for recombination.

28
Q

What is the function of DNA ligase in recombinant DNA technology?

A

DNA ligase joins DNA fragments, annealing donor and vector DNA to form recombinant DNA.

29
Q

What are the steps in amplifying DNA in vivo using bacterial cells?

A
  1. Isolate gene with restriction enzymes. 2. Insert gene into vector (plasmid). 3. Introduce plasmid into host cells. 4. Culture bacteria for protein production.
30
Q

What are the concerns with monoculture in transformed crops?

A

Monoculture reduces biodiversity and may allow crossbreeding with wild plants, creating superweeds.

31
Q

How does Southern blotting contribute to genetic fingerprinting?

A

DNA fragments are transferred to a nylon membrane and hybridized with labeled probes for detection.

32
Q

What is the genetic code, and why is it described as ‘degenerate’?

A

The genetic code specifies how base sequences in DNA or mRNA correspond to amino acids. It is degenerate because multiple codons can code for the same amino acid.

33
Q

What are the main types of stem cells?

A

Totipotent (can form any cell type), Pluripotent (can form most cell types), Multipotent (can form a limited range of cells), and Unipotent (can form only one cell type).

34
Q

What are the ethical considerations in using embryonic stem cells?

A

Embryonic stem cell research involves destroying embryos, raising ethical concerns about the beginning of human life.

35
Q

How are iPS cells generated, and why are they advantageous?

A

iPS cells are created by reprogramming somatic cells using transcription factors, avoiding the ethical issues of embryonic stem cells.

36
Q

What is the effect of increased methylation of tumor suppressor genes?

A

It silences these genes, preventing them from inhibiting cell division and potentially leading to cancer.

37
Q

How can mutations lead to non-functional proteins?

A

Mutations can alter the primary structure of a protein, disrupting bonds in the tertiary structure and affecting function, such as enzyme active site shape.

38
Q

What are the three main steps of PCR and their temperatures?

A
  1. Denaturation at 95°C. 2. Annealing at 55°C. 3. Extension at 70°C.
39
Q

How does miRNA regulate gene expression in mammals?

A

miRNA forms a complex with proteins to bind target mRNA, blocking its translation or marking it for degradation.

40
Q

What are some applications of genome sequencing?

A

Applications include identifying disease genes, improving crops, creating vaccines, and studying evolutionary relationships.

41
Q

What are the two types of genetic markers used to identify transformed cells?

A
  1. Antibiotic resistance genes. 2. Fluorescent or radioactive tags.
42
Q

How does gel electrophoresis separate DNA fragments?

A

DNA fragments are separated by size as they migrate through a gel towards the positive electrode under an electric field.

43
Q

What are the steps of genetic fingerprinting?

A
  1. Extract DNA. 2. Amplify VNTRs using PCR. 3. Separate fragments by gel electrophoresis. 4. Visualize bands under UV light.
44
Q

What are the benefits of recombinant DNA technology in agriculture?

A

Higher yields, pest-resistant crops, and enhanced nutritional content.

45
Q

What are the risks associated with gene therapy?

A

Risks include immune reactions, insertional mutagenesis, and ethical concerns regarding germline modifications.

46
Q

What is the difference between somatic and germline gene therapy?

A

Somatic gene therapy alters body cells to treat diseases, while germline therapy modifies gametes, affecting future generations.

A Level Biology (11 decks)

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