Brainscape's Knowledge GenomeTM

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


See full index

Biology > Week 8 - Molecular Genetics > Flashcards

Week 8 - Molecular Genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Which phase of the cell cycle is characterized by cells being metabolically active but not dividing?
A) G1
B) G0
C) S
D) G2

A

Answer: B) G0

Explanation: G0 is a resting phase where cells are metabolically active but not preparing to divide.

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

What is the primary enzyme responsible for unwinding the DNA double helix during replication?
A) DNA polymerase I
B) DNA polymerase III
C) Primase
D) DNA helicase

A

Answer: D) DNA helicase

Explanation: DNA helicase unwinds the double helix at the origins of replication

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

Which DNA strand is synthesized continuously during replication?

A) Lagging strand
B) Leading strand
C) Okazaki fragments
D) Complementary strand

A

Answer: B) Leading strand

Explanation: The leading strand is synthesized continuously in the 5’ to 3’ direction.

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

What is the role of primase in DNA replication?

A) Replace RNA primers with DNA
B) Unwind the DNA double helix
C) Synthesize RNA primers
D) Seal gaps between DNA fragments

A

Answer: C) Synthesize RNA primers

Explanation: Primase lays down RNA primers to initiate DNA synthesis by DNA polymerase.

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

During DNA replication, which enzyme is responsible for replacing RNA primers with DNA?

A) DNA polymerase III
B) DNA ligase
C) DNA polymerase I
D) DNA helicase

A

Answer: C) DNA polymerase I

Explanation: DNA polymerase I replaces RNA primers with DNA nucleotides.

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

What term describes the fragments of DNA synthesized on the lagging strand during replication?

A) Codons
B) Exons
C) Okazaki fragments
D) Nucleotides

A

Answer: C) Okazaki fragments

Explanation: Okazaki fragments are short segments of DNA synthesized on the lagging strand.

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

Which of the following types of RNA carries the genetic code from DNA for protein synthesis?

A) rRNA
B) tRNA
C) mRNA
D) snRNA

A

Answer: C) mRNA
Explanation: mRNA (messenger RNA) carries the genetic code from DNA to the ribosomes for protein synthesis.

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

In the lac operon, what happens when lactose is absent?

A) Transcription increases
B) RNA polymerase binds to the promoter
C) The repressor binds to the operator
D) The operon is permanently active

A

Answer: C) The repressor binds to the operator

Explanation: The presence of the repressor prevents transcription when lactose is absent.

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

What is a polycistronic mRNA molecule?

A) A molecule that codes for a single protein
B) A molecule that can be translated multiple times
C) A molecule that contains multiple genes under one promoter
D) A molecule that is never translated

A

Answer: C) A molecule that contains multiple genes under one promoter

Explanation: Polycistronic mRNA can code for multiple proteins due to multiple start and stop codons.

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

What characterizes an inducible operon?

A) Always active
B) Inactive until a specific molecule is present
C) Controlled only by environmental factors
D) Consistently expressed regardless of conditions

A

Answer: B) Inactive until a specific molecule is present

Explanation: Inducible operons are activated in response to specific signals, such as the presence of lactose.

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

Which enzyme is primarily responsible for catalyzing the formation of peptide bonds during translation?

A) tRNA
B) rRNA
C) mRNA
D) DNA polymerase

A

Answer: B) rRNA
Explanation: Ribosomal RNA (rRNA) is a structural and catalytic component of the ribosome, facilitating peptide bond formation.

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

Which of the following is NOT a characteristic of a good model organism?

A) Rapid reproduction
B) Complex developmental stages
C) Well-documented genetic information
D) Ease of maintenance

A

Answer: B) Complex developmental stages
Explanation: Good model organisms typically have simpler developmental stages for easier study.

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

What is the function of transcription factors in eukaryotic cells?

A) Degrade mRNA
B) Promote RNA polymerase binding to promoters
C) Catalyze peptide bonds
D) Unwind DNA during replication

A

Answer: B) Promote RNA polymerase binding to promoters

Explanation: Transcription factors are proteins that help initiate and regulate transcription by aiding RNA polymerase binding.

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

hat is the primary advantage of using E. coli in genetic research?

A) It is a multicellular organism
B) Its genome is extremely complex
C) It has a well-characterized genome and is easy to manipulate
D) It does not require any special growth conditions

A

Answer: C) It has a well-characterized genome and is easy to manipulate
Explanation: E. coli is widely used because it is simple to grow, manipulate, and has a well-studied genome

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

Which of the following best describes the role of RNA polymerase II?

A) Synthesizes DNA
B) Initiates transcription in prokaryotes
C) Synthesizes mRNA from a DNA template
D) Catalyzes the assembly of amino acids

A

Answer: C) Synthesizes mRNA from a DNA template
Explanation: RNA polymerase II transcribes DNA into mRNA in eukaryotic cells.

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

How does the presence of glucose affect the lac operon?

A) It activates transcription
B) It has no effect
C) It represses transcription
D) It promotes the binding of RNA polymerase

A

Answer: C) It represses transcription
Explanation: The presence of glucose inhibits the expression of the lac operon, as cells prefer glucose over lactose for energy.

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

What is the function of DNA ligase during DNA replication?

A) Synthesizes RNA primers
B) Unwinds the DNA helix
C) Joins Okazaki fragments together
D) Replaces RNA primers with DNA

A

Answer: C) Joins Okazaki fragments together
Explanation: DNA ligase connects the fragments of DNA synthesized on the lagging strand.

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

What term refers to the genetic material being tightly or loosely packaged, affecting gene expression?

A) Transcriptional regulation
B) Epigenetics
C) Operon function
D) Genetic drift

A

Answer: B) Epigenetics
Explanation: Epigenetics involves changes in gene expression due to the packaging of DNA, impacting whether genes are accessible for transcription.

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

What is the model organism used as a eukaryotic cell in research due to its domestication and ease of cultivation?

A

Saccharomyces cerevisiae (yeast) is a model eukaryotic cell that has been domesticated for over years, making it easy to grow and manipulate in research settings

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

What is the function of the lac operon in E. coli related to lactose metabolism?

A

The lac operon in E. coli encodes multiple enzymes necessary for lactose metabolism.

It is only activated when lactose is present in the environment, allowing the cell to efficiently utilize lactose as an energy source.

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

What type of mutants in the lac operon always have RNA polymerase unblocked and are unable to bind to the operator?

A

Constitutive mutants in the lac operon always have RNA polymerase unblocked and repressor unable to bind to the operator, leading to continuous transcription of the operon.

21
Q

What is the function of the CAP (Catabolite Activator Protein) in regulating the lac operon in response to glucose levels?

A

CAP is an allosteric protein that binds cAMP. It activates transcription of the lac operon only in low glucose conditions when cAMP levels are high, allowing efficient lactose metabolism.

22
Q

What is the process of DNA amplification that allows for pathogenic detection and DNA fingerprinting?

A

PCR (Polymerase Chain Reaction) is a process that amplifies DNA segments by denaturation, annealing, and extension using DNA polymerase, enabling pathogenic detection, DNA fingerprinting, and various DNA manipulation studies

23
Q

Which of the following is considered a key advantage of using Saccharomyces cerevisiae (baker’s yeast) as a model organism?

A) Its large genome size
B) Its ability to perform aerobic respiration
C) The ease of genetic manipulation
D) Its multicellular structure

A

Answer: C) The ease of genetic manipulation
Explanation: Saccharomyces cerevisiae is favored for its relatively simple genetics and ease of manipulation in laboratory settings

24
Q

Why is Drosophila melanogaster (fruit fly) widely used in genetic research?

A) It has a long lifespan
B) It has a complex immune system
C) It reproduces quickly and has a high mutation rate
D) It is a vertebrate model

A

Answer: C) It reproduces quickly and has a high mutation rate
Explanation: The rapid life cycle and high mutation frequency of Drosophila make it an ideal model for studying genetics.

25
Q

Which of the following organisms is known for its ability to regenerate lost body parts?

A) C. elegans (roundworm)
B) Xenopus laevis (African clawed frog)
C) Planaria (flatworm)
D) Mus musculus (house mouse)

A

Answer: C) Planaria (flatworm)

Explanation: Planaria are known for their remarkable regenerative capabilities, making them useful for studies on regeneration.

26
Q

What is a primary reason for using Caenorhabditis elegans (C. elegans) as a model organism?

A) Its large body size
B) Its simple nervous system and defined cell lineage
C) Its complex social behaviors
D) Its ability to photosynthesize

A

Answer: B) Its simple nervous system and defined cell lineage
Explanation: C. elegans has a fully mapped cell lineage and a simple nervous system, facilitating studies in development and neurobiology.

27
Q

In which area of research is Zebrafish (Danio rerio) particularly advantageous?

A) Behavioral studies in mammals
B) Developmental biology due to transparent embryos
C) Studies of prokaryotic genetics
D) Research on plant genetics

A

Answer: B) Developmental biology due to transparent embryos

Explanation: The transparency of zebrafish embryos allows for direct observation of developmental processes.

28
Q

What significant contribution to genetics has Mus musculus (house mouse) provided?

A) Insight into plant genetics
B) Models for human diseases
C) Understanding of microbial genetics
D) Studies on photosynthesis

A

Answer: B) Models for human diseases
Explanation: Mus musculus is extensively used in mammalian biology and medicine, particularly for modeling human diseases

29
Q

What is a unique feature of the Arabidopsis thaliana plant model organism?

A) It has a very long generation time
B) It is a complex multicellular organism
C) It has a small genome and rapid life cycle
D) It can be genetically modified only in the field

A

Answer: C) It has a small genome and rapid life cycle
Explanation: Arabidopsis thaliana is favored for plant genetics due to its small genome size and short generation time.

30
Q

Which model organism is known for its use in studies related to aging and longevity?

A) Mus musculus
B) C. elegans
C) Drosophila melanogaster
D) Zebrafish

A

Answer: B) C. elegans
Explanation: C. elegans is frequently used in research related to aging due to its short lifespan and well-characterized genetics.

31
Q

Which model organism’s genome was the first to be fully sequenced, providing valuable insights into developmental processes?

A) Drosophila melanogaster
B) Mus musculus
C) C. elegans
D) Arabidopsis thaliana

A

Answer: C) C. elegans
Explanation: The genome of C. elegans was the first to be fully sequenced, aiding in various biological research fields

32
Q

In genetic research, which organism serves as a model for studying human immune responses?

A) Drosophila melanogaster
B) Mus musculus
C) Zebrafish
D) Saccharomyces cerevisiae

A

Answer: B) Mus musculus

Explanation: Mus musculus is widely used to study mammalian immune responses due to its genetic similarities to humans.

33
Q

In terms of ecological research, why might Drosophila serve as a model organism?

A) Its symbiotic relationships with bacteria
B) Its role in plant pollination
C) Its population dynamics and adaptability
D) Its ability to survive extreme environments

A

Answer: C) Its population dynamics and adaptability

Explanation: Drosophila is useful in ecological studies due to its rapid reproduction and adaptability to different environments.

34
Q

What is the model vertebrate?

A

Danio rerio (Zebrafish)

35
Q

What is the model organism for genetics?

A

Drosophila melanogaster - fruit fly

36
Q

What are good model organisms for animals?

A

Caenorhabditis elegans (nematode) - CNS and PNS, digestive tract, tiny 959 cells to make a adult hermaphrodite

37
Q

What are bad model organisms for animals?

A

Amphimedon queenslandica = sponge is hard to grow in aquariums and is in the Great Barrier Reef, can be genetically modified

38
Q

What is the Model mammal?

A

Mus musculus (house mouse)

39
Q

What is the Model marsupial?

A

Macropus eugenii (Tammar wallaby)

40
Q

What is the Model primate ‘ almost humans’ - space travel, developmental?

A

Macaca mulatta (rhesus monkey)

41
Q

What is positive vs. negative control?

A
  1. Blockage of promoters STOPS transcription = negative control
  2. Activation of promoters INCREASES transcription = positive control
42
Q

What mutant causes lac operon to be always expressed even without lactose?

A

Constitute mutant

43
Q

What is an inducible system?

A

turned on by something (lactose)

44
Q

What mutant causes the lac operon to never be expressed?

A

Non-inducible mutants

45
Q

What does a repressor protein do?

A

If repressor protein is present, it will bind to the operator and stop RNA polymerase

46
Q

What type of protein is the lac repressor?

A

an allosteric protein

47
Q

When does lac operon turn on/off?

A
  1. When lactose is absent, it will block the passage of rna polymerase
  2. When lactose is present, repressor fall off the operator and goes inactive, and the lac operon turns on and makes proteins
48
Q

What kind of system is the lac operon under?

A
  1. inducible system with negative control
49
Q

inducible/repressible and negative/positive control?

A

Inducible vs. repressible systems = referring to extracellular signals/outside the cell, eg. lactose outside the cell induces the cell to make the lac operon

Negative vs. positive control = what’s happening at the promoter

50
Q

What are the 3 difficulties with studying other organisms?

A
  1. Difficult to keep alive, get to reproduce
  2. Difficult to genetically manipulate
  3. Difficult to sequence (have to access the organism’s genome)

Biology (12 decks)

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