btech final 16 17 18 19

What does "reprogramming" refer to in cell biology?

A) The process of converting RNA into DNA

B) The ability of fully differentiated cells to become pluripotent

C) The reverse transcription of genetic information

D) The transition from a fertilized egg to differentiated adult cells

B) The ability of fully differentiated cells to become pluripotent

What is the initial potency of a fertilized egg in terms of its ability to form different cell types?

A) Unipotent

B) Multipotent

C) Totipotent

D) Pluripotent

C) Totipotent

As development progresses, what happens to the potency of cells, resulting in a more limited range of cell types in the adult form?

A) Potency remains constant

B) Potency increases

C) Potency decreases

D) Potency becomes unpredictable

C) Potency decreases

What guides the funneling of cells into distinct paths during the developmental process?

A) Random cellular decisions

B) DNA mutations

C) Signaling and interactions between cells

D) External environmental factors

C) Signaling and interactions between cells

In the context of developmental biology, what does "potency" refer to?

A) The ability of cells to divide rapidly

B) The potential of cells to revert to a pluripotent state

C) The range of cell types a cell can become

D) The size of a cell during development

C) The range of cell types a cell can become

At the blastocyst stage, which part of the embryo has a restricted fate and forms the embryo itself?

A) Unipotent cells

B) Trophoblast cells

C) Inner cell mass

D) Totipotent zygote

C) Inner cell mass

From which part of the blastocyst are pluripotent embryonic stem cells (ES cells) derived?

A) Trophoblast cells

B) Placenta

C) Inner cell mass

D) Totipotent zygote

C) Inner cell mass

How does early differentiation primarily occur in cells at the molecular level?

A) By altering gene expression

B) Through the activation of pluripotency associated genes

C) By acquiring new genetic material

D) By reprogramming the epigenome

A) By altering gene expression

What is the outcome regarding gene content in fully differentiated cells?

A) Gene content is lost

B) Gene content remains the same

C) Gene content increases

D) Gene content becomes totipotent

B) Gene content remains the same

Which term best defines the transformation of somatic cells into embryonic stem cells?

A) Cloning

B) Differentiation

C) Reprogramming

D) Reproduction

C) Reprogramming

What is the primary function of the somatic cell in nuclear transfer experiments?

A) To provide genetic diversity

B) To serve as a source of cytoplasm

C) To contribute its nucleus for reprogramming

D) To act as a control group for comparison

C) To contribute its nucleus for reprogramming

Why is the reprogramming of the donor nucleus essential in nuclear transfer experiments?

A) To create a control group for comparison

B) To extract cytoplasm from the somatic cell

C) To enable the generation of a genetically identical organism

D) To assess the characteristics of the recipient oocyte

C) To enable the generation of a genetically identical organism

What role does the recipient oocyte play in nuclear transfer experiments?

A) It serves as a control group for comparison

B) It supplies essential cytoplasm for reprogramming

C) It extracts the nucleus from a somatic cell

D) It examines somatic cell characteristics

B) It supplies essential cytoplasm for reprogramming

What is the significance of creating an organism that is genetically identical to the donor organism?

A) To demonstrate the versatility of somatic cells

B) To explore the properties of enucleated oocytes

C) To test the concept of reproductive cloning

D) To study the cytoplasm of oocytes

C) To test the concept of reproductive cloning

In the context of a nuclear transfer procedure, what does "reproductive cloning" refer to?

A) Duplicating the somatic cell nucleus to create a genetic copy

B) Creating a novel organism with unique genetic characteristics

C) Generating fully identical organisms with the donor's genes

D) Reproducing offspring from the donor organism through cellular duplication

C) Generating fully identical organisms with the donor's genes

How is the nucleus from a fully differentiated somatic cell introduced into the enucleated egg?

A) Through genetic modification

B) By using specialized pipettes

C) By injecting it into the egg's nucleus

D) By merging the two cells' membranes -

B) By using specialized pipettes

Who was the first mammal to be cloned, marking a significant milestone in the late 1990s?

A) Einstein the cat

B) Dolly the sheep

C) Fido the dog

D) Whiskers the rabbit

B) Dolly the sheep

What technique was used to create Dolly the sheep, the first cloned mammal?

A) Natural reproduction

B) In vitro fertilization

C) Nucleus transplantation

D) Artificial insemination

C) Nucleus transplantation

Cloning, particularly in the case of Dolly the sheep, was notorious for its high inefficiency. Approximately how many oocytes were required for successful nuclear transplantation in Dolly's case?

A) 100 oocytes

B) 200 oocytes

C) 300 oocytes

D) Over 400 oocytes

D) Over 400 oocytes

In the context of development, what happens to a cell's capability for nucleus reprogramming as it becomes more specialized?

A) It increases

B) It remains constant

C) It decreases

D) It depends on the cell type

C) It decreases

Nucleus reprogramming is less effective in cells that have undergone significant differentiation. Why is this a challenge in cloning?

A) Cloning only requires highly differentiated cells

B) Cloning relies on undifferentiated cells

C) Nucleus reprogramming is not relevant to cloning

D) Cloning is unaffected by differentiation

B) Cloning relies on undifferentiated cells

In the Nobel Prize 2012, which scientists demonstrated that mature cells can be reprogrammed to pluripotency?

A) Gurdon and Yamanaka

B) Watson and Crick

C) Franklin and Wilkins

D) Mendel and Darwin

A) Gurdon and Yamanaka

Which scientist's work led to the development of Induced Pluripotent Stem (iPS) cells?

A) Albert Einstein

B) Shinya Yamanaka

C) Charles Darwin

D) Isaac Newton

B) Shinya Yamanaka

What is the primary achievement of Shinya Yamanaka's research on iPS cells?

A) Creating completely new cell types

B) Discovering a cure for cancer

C) Reprogramming differentiated cells into pluripotent stem cells

D) Cloning animals

C) Reprogramming differentiated cells into pluripotent stem cells

How are iPS cells typically created?

A) Through genetic mutations

B) By using specific transcription factors

C) By extracting them from embryos

D) Through exposure to high radiation

B) By using specific transcription factors

What is the significance of iPS cells in the field of medicine?

A) They can only differentiate into a single cell type

B) They have no medical applications

C) They can be used to treat a wide range of diseases and injuries

D) They are only relevant in veterinary medicine

C) They can be used to treat a wide range of diseases and injuries

What is the defining characteristic of iPS cells?

A) They are obtained exclusively from adult humans

B) They cannot differentiate into any other cell types

C) They have the potential to differentiate into various cell types

D) They are not pluripotent

C) They have the potential to differentiate into various cell types

In Shinya Yamanaka's experiment, which specific type of human cells were reprogrammed into induced pluripotent stem (iPS) cells for cardiac tissue regeneration?

A) Cardiac muscle cells

B) Brain cells

C) Human fibroblast cells

D) Red blood cells

C) Human fibroblast cells

Which specific factors are used by Yamanaka to reprogram cells into iPS cells?

A) Nitrogen and oxygen

B) Oct4 and cMyc

C) Hydrogen and helium

D) Sodium and potassium

B) Oct4 and c-Myc

What is one characteristic of cancer?

A) Rapid cell division

B) Systematic breakdown of control mechanisms

C) Enhanced coordination with surrounding tissues

D) Inhibition of abnormal cell behavior

B) Systematic breakdown of control mechanisms

What is the principal role of protooncogenes in normal cells?

A) Inhibiting cell growth

B) Regulating immune responses

C) Regulating growth and survival until mutation

D) Promoting apoptosis

C) Regulating growth and survival until mutation

What is the typical outcome when protooncogenes undergo mutation?

A) They become tumor suppressor genes

B) They lose all function

C) They continue to regulate normal cell behavior

D) They may become oncogenes and promote uncontrolled cell growth -

D) They may become oncogenes and promote uncontrolled cell growth

What is the central role of tumor suppressor genes in regulating cell growth?

A) Promoting uncontrolled cell division

B) Halting cell division or inducing cell death to prevent uncontrolled growth

C) Acting as oncogenes to enhance cell growth

D) Promoting cell differentiation

B) Halting cell division or inducing cell death to prevent uncontrolled growth

What initiates the transition from the G1 phase to the S phase in the cell cycle?

A) DNA replication

B) G1 cyclin expression

C) Mitosis completion

D) Cell differentiation

B) G1 cyclin expression

What do cells consider when determining whether to enter the cell cycle?

A) The cell's age

B) The balance of growth promoting and inhibiting signals

C) The cell's position in the body

D) The presence of cell surface receptors -

B) The balance of growth-promoting and inhibiting signals

Which transcription factor is responsible for controlling transcription activation during the cell cycle?

A) p53 tumor suppressor

B) Cyclin D

C) E2F transcription factor

D) CDK inhibitor

C) E2F transcription factor

During the early G1 phase, what is the role of the Rb protein in relation to E2F?

A) Rb activates E2F to promote cell division

B) Rb binds to E2F and enhances its transcriptional activity

C) Rb prevents E2F from binding to DNA, inhibiting its transcriptional activity

D) Rb promotes G1 cyclin expression

C) Rb prevents E2F from binding to DNA, inhibiting its transcriptional activity

How does G1 cyclin CDK (Cyclin Dependent Kinase) contribute to the regulation of the cell cycle?

A) It promotes apoptosis

B) It inhibits Rb phosphorylation

C) It promotes E2's binding to Rb

D) It phosphorylates Rb, preventing Rb from binding to E2F

D) It phosphorylates Rb, preventing Rb from binding to E2F

What does the abbreviation "Rb" in the context of the Rb gene stand for?

A) Rare base

B) Retinoblastoma

C) Rapid breakdown

D) Regulating body

B) Retinoblastoma

Which medical condition results from a defect in the Rb gene?

A) Cataracts

B) Glaucoma

C) Retinoblastoma

D) Macular degeneration

C) Retinoblastoma

Which specific tissue is primarily impacted by retinoblastoma, a disease associated with a defect in the Rb gene?

A) Liver tissue

B) Lung tissue

C) Retinal tissue

D) Skin tissue

C) Retinal tissue

In what inheritance pattern is Familial Retinoblastoma typically inherited?

A) Xlinked inheritance

B) Autosomal recessive inheritance

C) Autosomal dominant inheritance

D) Y-linked inheritance -

C) Autosomal dominant inheritance

What is a notable characteristic of Familial Retinoblastoma concerning unaffected individuals who may carry the disease allele?

A) Unaffected individuals are never carriers

B) Unaffected individuals do not exist in the case of Familial Retinoblastoma

C) Unaffected individuals with a defective Rb gene can have affected offspring

D) Unaffected individuals are always homozygous for the disease allele

C) Unaffected individuals with a defective Rb gene can have affected offspring

When does the genetic predisposition to cancer become relevant in individuals with one functional Rb gene (Rb+)?

A) It is always relevant from birth

B) It never becomes relevant in such individuals

C) The predisposition becomes relevant when a second mutation occurs in the other Rb gene, leading to tumor development

D) It becomes relevant only in old age

C) The predisposition becomes relevant when a second mutation occurs in the other Rb gene, leading to tumor development

Among the listed mechanisms of Rb gene inactivation, which of the following is linked to the increased loss of heterozygosity and the loss of function of the Rb gene, ultimately leading to cancer?

A) Point Mutation

B) Chromosome loss or translocation

C) Epigenetic Changes

D) All of the above

D) All of the above

What specialized compartment within colon crypts plays a crucial role in cell renewal and regeneration?

A) Intestinal Function

B) Stem Cell Niche

C) Cell Movement

D) Cancer Barrier

B) Stem Cell Niche

In normal conditions, after being renewed from the stem cell niche at the colon crypt base or the crypts of the large or small intestine, where do cells typically migrate to?

A) They return to the stem cell niche

B) They enter the bloodstream

C) They ascend toward the villi

D) They move toward the lumen of the intestine

D) They move toward the lumen of the intestine

How does the "Cancer Barrier" relate to colon tumor formation risk?

A) It acts as protooncogenes

B) It acts as oncogenes

C) It identifies obstacles to tumor formation, including cancer cell accumulation if shedding is hindered

D) It acts as a kinase, exerting influence on cellular respiration

C) It identifies obstacles to tumor formation, including cancer cell accumulation if shedding is hindered

What potential risk is associated with the hindrance of cancer cell shedding in the colon?

A) hinder cancer cell accumulation

B) Enhanced cancer cell elimination

C) Accumulation of cancer cells within the colon

D) Prevention of cancer cell division

C) Accumulation of cancer cells within the colon

Which gene is associated with mutations linked to Familial Adenomatous Polyposis (FAP) and is also involved in colon cancer development?

A) APC Gene

B) BRCA1 Gene

C) p53 Gene

D) HER2 Gene

A) APC Gene

What is FAP an abbreviation for in the context of colon cancer?

A) Fast Acting Polyps

B) Familial Adenomatous Polyposis

C) Functional Adenomatous Proliferation

D) FAP has no specific abbreviation in this context -

B) Familial Adenomatous Polyposis

Which of the following is a consequence of mutations in the APC gene regarding colon cancer development?

A) Decreased risk of tumor formation

B) Enhanced immune response

C) Familial Adenomatous Polyposis (FAP)

D) Reduced risk of FAP

C) Familial Adenomatous Polyposis (FAP)

In the context of colon cancer, what is the primary consequence of a loss of the APC gene?

A) Enhanced regulation of cell growth

B) Reduced activation of Wnt signals

C) Continuous activation of Wnt signals

D) Increased shedding of cells

C) Continuous activation of Wnt signals

What molecule is known to accumulate and trigger Wnt signaling activation when the APC gene is lost?

A) E cadherin

B) β-catenin

C) p53

D) E2F -

B) β-catenin

In the early stages of colon cancer, what is a common feature associated with the loss of the APC gene and Wnt signaling activation?

A) Decreased cell proliferation

B) Inhibition of uncontrolled cell growth

C) Abnormal regulation of cell division

D) Uncontrolled cell growth and tumor formation

D) Uncontrolled cell growth and tumor formation

Which condition involves ABL gene activation due to chromosomal translocation?

A) Non small cell lung cancer

B) Chronic Myelogenous Leukemia (CML)

C) Alzheimer's disease

D) Type 2 diabetes -

B) Chronic Myelogenous Leukemia (CML)

In Chronic Myelogenous Leukemia (CML), what event leads to the activation of the ABL gene?

A) ABL gene deletion

B) ABL gene mutation

C) ABL gene amplification

D) Chromosomal translocation

D) Chromosomal translocation

What term is used to describe genes like ABL, which have the potential to cause uncontrolled cell growth when mutated?

A) Tumor suppressor genes

B) Housekeeping genes

C) Protooncogenes

D) Apoptosis genes -

C) Proto-oncogenes

What is the primary mechanism of action of Gleevec (imatinib) in the treatment of CML?

A) It enhances the activity of ABL kinase

B) It suppresses the immune system to fight CML

C) It inhibits ABL kinase, rendering it inactive

D) It promotes the growth of cancer cells

C) It inhibits ABL kinase, rendering it inactive

Which type of immunity provides a broad defense mechanism and is less specific to particular pathogens?

A) Innate immunity

B) Adaptive immunity

C) Both A and B

D) None of the above

A) Innate immunity

What is a characteristic feature of adaptive immunity?

A) Immediate response

B) Broad defense mechanism

C) Less specific to pathogens

D) Highly specific to pathogens

D) Highly specific to pathogens

Which type of immunity involves the production of antibodies by B cells?

A) Humoral immunity

B) Cell mediated immunity

C) Both A and B

D) Neither A nor B -

A) Humoral immunity

Cell mediated immunity primarily relies on which type of immune cells?

A) B cells

B) Antibodies

C) T cells

D) Macrophages -

C) T cells

What is a common feature present in both Humoral and Cellular Immunity?

A) Presence of antigen receptors

B) Production of cytokines

C) Secretion of complement proteins

D) Activation of natural killer cells

A) Presence of antigen receptors

What is the main role of antigen receptors in both Humoral and Cellular Immunity?

A) Recognizing self from non-self antigens

B) Initiating inflammation

C) Activating complement proteins

D) Identifying specific antigens for immune response -

D) Identifying specific antigens for immune response

What is another term for an antibody (B Cell Receptor)?

A) Immunoglobulin (IG)

B) Immunosuppressor

C) Antigen

D) Cytokine -

A) Immunoglobulin (IG)

What is the basic structural composition of an antibody?

A) Two heavy chains

B) Two light chains

C) Two identical heavy chains and two light chains

D) One heavy chain and one light chain

C) Two identical heavy chains and two light chains

What are the two forms of the Antibody (B-Cell Receptor)?

A) Membrane-bound and anchored

B) Secreted and anchored

C) Secreted and membrane-bound

D) Extracellular and intracellular

C) Secreted and membrane-bound

In which form is the Antibody (B-Cell Receptor) predominantly used during infections?

A) Membrane-bound form

B) Secreted form

C) Both forms equally

D) None of the above

B) Secreted form

What are the primary components of the T-Cell Receptor (TCR)?

A) Heavy and light chains

B) Alpha and beta chains

C) Variable and constant regions

D) Fab and Fc regions -

B) Alpha and beta chains

What is a key characteristic of antibodies regarding specificity?

A) They target a wide range of structures

B) They target similar structures

C) Each antibody is highly specific, targeting a unique structure

D) They lack specificity

C) Each antibody is highly specific, targeting a unique structure

What role do Hypervariable Regions play in antigen recognition?

A) They have no role in antigen recognition

B) They are supplementary to antigen recognition

C) They are crucial for precise antigen recognition

D) They hinder antigen recognition

C) They are crucial for precise antigen recognition

What is the relationship between each B cell and the antibodies it produces?

A) Each B cell produces identical antibodies

B) Each B cell produces a unique antibody

C) Each B cell produces antibodies with similar functions

D) Each B cell produces antibodies with identical CDR sequences

B) Each B cell produces a unique antibody

Why is it impractical to have a unique gene for each antibody in the human genome?

A) Limited storage capacity in B cells

B) High mutation rate in antibody genes

C) Cost constraints in gene synthesis

D) Large number of potential antibody specificities

D) Large number of potential antibody specificities

Which mechanism contributes to the generation of a diverse repertoire of antibody specificities despite the limitation of a finite number of genes?

A) Somatic recombination

B) DNA replication

C) RNA transcription

D) Protein translation

A) Somatic recombination

How many Variable (V), Diversity (D), and Joining (J) segments are available for the heavy chain gene?

A) 45 V, 23 D, and 6 J segments

B) 23 V, 45 D, and 6 J segments

C) 6 V, 45 D, and 23 J segments

D) 45 V, 6 D, and 23 J segments

A) 45 V, 23 D, and 6 J segments

What is the minimum requirement of gene segments for a functional antibody heavy chain?

A) One V and one D segment

B) One D and one J segment

C) One V, one D, and one J segment

D) One V segment only

C) One V, one D, and one J segment

What is the significance of having a large number of V, D, and J segments for heavy chain gene rearrangement?

A) It reduces the diversity of antibody repertoires

B) It limits the specificity of antibody binding

C) It increases the potential for generating a wide range of antibody specificities

D) It decreases the efficiency of antibody production

C) It increases the potential for generating a wide range of antibody specificities

Which lymphocyte specific recombinases are responsible for mediating V(D)J recombination?

A) TdT and AID

B) CD3 and CD4

C) RAG1 and RAG2

D) MHC I and MHC II

C) Recombination Activating Gene (RAG): RAG1 and RAG2

Which of the following may be involved in Junctional Imprecision?

A) Perfect alignment of gene segments

B) Nucleotide substitution only

C) Nucleotide insertion or deletion

D) Complete deletion of gene segments

C) Nucleotide insertion or deletion

How does Junctional Imprecision contribute to diverse antibody sequences?

A) By reducing genetic variability

B) By limiting the number of possible antibody structures

C) By ensuring perfect recombination of gene segments

D) By introducing variations in nucleotide sequences

D) By introducing variations in nucleotide sequences

How does somatic mutation contribute to the enhancement of antibody affinity for antigens?

A) By reducing the mutation rate

B) By altering the constant region of the antibody

C) By introducing random mutations in the variable region

D) By decreasing the diversity of antibody sequences

C) By introducing random mutations in the variable region

What is the primary outcome of affinity maturation in the immune response?

A) Reduction in antibody diversity

B) Decrease in antibody production

C) Enhancement of antibody affinity for antigens

D) Suppression of somatic mutation

C) Enhancement of antibody affinity for antigens

What is the consequence of allelic exclusion on B cell development?

A) Each B cell produces multiple antibodies

B) Each B cell expresses only one antibody

C) B cells lose their ability to produce antibodies

D) B cells undergo somatic expansion

B) Each B cell expresses only one antibody

What is allelic expansion used for in the context of monoclonal antibody production?

A) To reduce antibody diversity

B) To increase somatic mutation rates

C) To clone and propagate B cells with identical antibody specificity

D) To suppress antibody production

C) To clone and propagate B cells with identical antibody specificity

Which of the following best describes the purpose of monoclonal antibody production?

A) To generate antibodies with diverse specificities

B) To suppress antibody expression

C) To produce antibodies from a single B cell clone

D) To limit the immune response

C) To produce antibodies from a single B cell clone

How does the affinity of antibodies during a secondary infection compare to that during a primary infection?

A) The affinity is weaker in a secondary infection

B) The affinity is stronger in a secondary infection

C) The affinity is equal in both primary and secondary infections

D) The affinity varies unpredictably

B) The affinity is stronger in a secondary infection

What are monoclonal antibodies primarily used for in targeted therapies?

A) Inducing inflammation

B) Inhibiting antibody production

C) Targeting specific molecules or cells involved in disease processes

D) Suppressing immune responses

C) Targeting specific molecules or cells involved in disease processes

Which growth factor receptor is overexpressed in approximately 30% of breast cancers?

A) EGFR (Epidermal Growth Factor Receptor)

B) PDGFR (Platelet-Derived Growth Factor Receptor)

C) HER2 (Human Epidermal Growth Factor Receptor 2)

D) IGF-1R (Insulin-like Growth Factor 1 Receptor)

C) HER2 (Human Epidermal Growth Factor Receptor 2)

What role does the overexpression of growth factor receptors like HER2 play in cancer development?

A) It suppresses cancer cell proliferation

B) It inhibits angiogenesis

C) It promotes apoptosis

D) It enhances cell growth, survival, and proliferation, contributing to tumor growth and progression

D) It enhances cell growth, survival, and proliferation, contributing to tumor growth and progression

What type of treatment is Herceptin?

A) Chemotherapy

B) Radiation therapy

C) Hormone therapy

D) Antibody

based therapy - D) Antibody-based therapy

What specific target does Herceptin recognize on cancer cells?

A) EGFR

B) PDGFR

C) HER2

D) IGF

1R - C) HER2

How does Herceptin affect HER2 function in cancer cells?

A) It enhances HER2 signaling

B) It has no impact on HER2 function

C) It blocks HER2 function

D) It promotes HER2 overexpression

C) It blocks HER2 function

In addition to blocking HER2 function, what other potential mechanism of action does Herceptin possess?

A) It inhibits apoptosis in cancer cells

B) It induces angiogenesis

C) It recruits immune cells to kill cancer cells

D) It promotes cancer cell proliferation

C) It recruits immune cells to kill cancer cells

What is the primary source of peptides presented by Major Histocompatibility Complex Class I (MHC-I) molecules?

A) Extracellular proteins

B) Intracellular proteins in the cytoplasm

C) Membrane-bound proteins

D) Nuclear proteins

B) Intracellular proteins in the cytoplasm

With which type of T cells does MHC Class I primarily interact?

A) Helper T cells (CD4+ T cells)

B) Regulatory T cells (Tregs)

C) Innate cells

D) Cytotoxic T cells (CD8+ T cells)

D) Cytotoxic T cells (CD8+ T cells)

On which types of cells is MHC Class II primarily expressed?

A) Cytotoxic T cells (CD8+ T cells)

B) Cytotoxic T cells (CD4+ T cells)

C) B cells and dendritic cells

D) Natural Killer cells

C) B cells and dendritic cells

What is the main source of peptides presented by MHC Class II molecules?

A) Intracellular proteins in the cytoplasm

B) Extracellular substances taken up via phagocytosis

C) Membrane-bound proteins

D) Viral proteins -

B) Extracellular substances taken up via phagocytosis

With which type of T cells does MHC Class II primarily interact?

A) Regulatory T cells (Tregs)

B) Cytotoxic T cells (CD8+ T cells)

C) Natural Killer cells

D) Helper T cells (CD4+ T cells)

D) Helper T cells (CD4+ T cells)

What is the primary function of CD8 T cells?

A) Support and assist other immune cells

B) Produce antibodies

C) Kill infected cells (cytotoxic)

D) Regulate immune responses

C) Kill infected cells (cytotoxic)