Apoptosis and Its Roles in Development
42 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which process is primarily responsible for the removal of cells during the development of the tadpole's tail?

  • Mitosis
  • Necrosis
  • Autophagy
  • Apoptosis (correct)

Approximately how many cells are lost through apoptosis in the human body each hour?

  • Trillions
  • Millions
  • Thousands
  • Billions (correct)

Which of the following is NOT a characteristic of apoptosis?

  • Cell shrinkage
  • DNA fragmentation into 200 bp units
  • Induction of an immune response (correct)
  • Cytochrome c release from the mitochondria

What crucial role does apoptosis play in the immune system's development and maintenance?

<p>Removing immune cells that don't pass certain tests (D)</p> Signup and view all the answers

How does apoptosis differ from necrosis in terms of cellular impact?

<p>Apoptosis is a clean cell death, whereas necrosis causes cell lysis and inflammation (A)</p> Signup and view all the answers

Which cellular process is characterized by cellular condensation and intact cell membranes?

<p>Apoptosis (D)</p> Signup and view all the answers

What is a key distinction regarding energy requirements between apoptosis and necrosis?

<p>Apoptosis requires ATP, necrosis depletes it (D)</p> Signup and view all the answers

How does the pattern of DNA fragmentation differ between apoptosis and necrosis?

<p>Apoptosis shows ladder-like fragmentation, necrosis shows random fragmentation (A)</p> Signup and view all the answers

What is the typical tissue response to apoptosis, compared to necrosis?

<p>Apoptosis is followed by phagocytosis without inflammation, necrosis causes an inflammatory reaction (B)</p> Signup and view all the answers

Which of the following is a typical consequence of necrosis?

<p>Inflammation of surrounding tissue (C)</p> Signup and view all the answers

What is the role of phagocytes in programmed cell death?

<p>They engulf apoptotic cell remains (D)</p> Signup and view all the answers

Which of these is associated with triggering apoptosis?

<p>Exposure to UV light (D)</p> Signup and view all the answers

What is the initial step in apoptosis after the pathway has been activated?

<p>The actual 'suicide' of the cell (D)</p> Signup and view all the answers

Which cellular process, when reduced, can contribute to the development of cancer?

<p>Apoptosis (D)</p> Signup and view all the answers

What is the primary underlying cause of cancer at a molecular level?

<p>Mutations in genes leading to altered proteins (A)</p> Signup and view all the answers

Which of the following is NOT a primary type of gene implicated in cancer development?

<p>Histone modifying genes (A)</p> Signup and view all the answers

What distinct trigger is required for apoptosis in cardiac myocytes during ischemia specifically, versus during reperfusion injury?

<p>Distinct initiator caspases (A)</p> Signup and view all the answers

In ischemia/reperfusion injury, which cell type undergoes apoptosis first?

<p>Endothelial cells (C)</p> Signup and view all the answers

Which of the following is NOT a typical role of apoptosis in adult organisms?

<p>Neurodevelopment (A)</p> Signup and view all the answers

What is a key characteristic of necroptosis that distinguishes it from traditional necrotic cell death?

<p>It is regulated by RIP1 and RIP3 kinases. (C)</p> Signup and view all the answers

In the context of stress-induced autophagy, what is most commonly observed?

<p>It is a cytoprotective mechanism that promotes homeostasis and survival (A)</p> Signup and view all the answers

Which of the following best describes the double-membraned vesicles involved in autophagy?

<p>Autophagosomes (D)</p> Signup and view all the answers

What is a key feature of cell death by necroptosis?

<p>It involves rapid plasma membrane permeabilization and release of DAMPs (C)</p> Signup and view all the answers

Which of these conditions is typically associated with deficient apoptosis?

<p>Autoimmunity (C)</p> Signup and view all the answers

What is a key difference between the roles of autophagy in developmental contexts versus a stress response?

<p>Autophagy is protective in stress and can be lethal in some developmental settings (C)</p> Signup and view all the answers

Which condition is NOT typically linked to necroptosis?

<p>Autoimmunity (C)</p> Signup and view all the answers

What is the primary function of tumor suppressor genes?

<p>To inhibit cell proliferation, acting as a brake on cell division (A)</p> Signup and view all the answers

Which of the following processes is directly triggered by the phosphorylation of the p53 protein?

<p>Cell cycle arrest and DNA repair (B)</p> Signup and view all the answers

What is the consequence of a disruption or deletion of the p53 gene?

<p>Uncorrected DNA damage and uncontrolled cell proliferation (B)</p> Signup and view all the answers

A mutation that leads to a constantly activated ras protein would be considered what type of gene?

<p>An oncogene (C)</p> Signup and view all the answers

What is the role of the p21 gene in the context of p53 activation?

<p>To induce cell cycle arrest for DNA repair (B)</p> Signup and view all the answers

Which of the following is NOT a gene associated with a hereditary cancer syndrome, according to the text?

<p>DCC (D)</p> Signup and view all the answers

What is a key characteristic of apoptosis that distinguishes it from necrosis?

<p>The cell destroys itself from within, avoiding leakage (C)</p> Signup and view all the answers

Which genes are primarily involved in transcriptional regulation, based on the text?

<p>WT1, Rb1 and p53 (B)</p> Signup and view all the answers

What is the primary mechanism by which caspases are activated?

<p>Through proteolytic cleavage (D)</p> Signup and view all the answers

Which of the following is NOT a typical characteristic of caspase activation?

<p>Inhibition of catalytic sites (B)</p> Signup and view all the answers

Which pathway is typically associated with death receptor-mediated apoptosis?

<p>The extrinsic pathway (A)</p> Signup and view all the answers

Which of the following ligands is known to activate the Fas receptor?

<p>FasL (C)</p> Signup and view all the answers

What is the role of 'death domains' in apoptosis?

<p>They trigger caspase activation following receptor trimerization (A)</p> Signup and view all the answers

In the intrinsic apoptotic pathway, what role does cytochrome c play?

<p>It is released from the mitochondria and helps activate Caspase 9 as part of the apoptosome complex (B)</p> Signup and view all the answers

What technique is used to detect DNA fragmentation during apoptosis, by tagging DNA strand breaks?

<p>TUNEL staining (C)</p> Signup and view all the answers

Which of the following is NOT typically used to directly assess caspase activity?

<p>Nuclear morphology assessment (D)</p> Signup and view all the answers

Flashcards

Apoptosis

A tightly regulated process of cell death that occurs in a controlled way, preserving the surrounding cells and tissues.

Necrosis

Uncontrolled cell death that occurs due to external factors like injury or toxins. It's messy, damaging nearby cells and triggering inflammation.

Cell Death Regulation

A process where the body maintains a constant number of cells by ensuring unwanted or damaged cells are removed, maintaining tissue balance.

Immune Cell Apoptosis

The process of removing harmful or defective cells from the body's immune system, preventing them from causing harm.

Signup and view all the flashcards

DNA Cleavage in Apoptosis

The breakdown of DNA into smaller fragments, characteristic of apoptosis.

Signup and view all the flashcards

Programmed Cell Death

A form of programmed cell death triggered by specific signals, leading to a controlled cell destruction process.

Signup and view all the flashcards

Necroptosis

A type of programmed cell death distinct from both apoptosis and necrosis. It is triggered by specific signaling pathways, leading to inflammation.

Signup and view all the flashcards

Autophagy

A process where cells recycle their own components through the formation of lysosomes, allowing for cellular renewal and survival.

Signup and view all the flashcards

What is Apoptosis?

A programmed cell death process characterized by cellular condensation, intact membranes, ATP dependence, and phagocytosis without inflammation. It involves ladder-like DNA fragmentation and affects individual cells.

Signup and view all the flashcards

What is Necrosis?

A form of cell death characterized by cellular swelling, broken membranes, ATP depletion, and lysis, leading to an inflammatory reaction. DNA fragmentation is random, and it affects whole tissue areas.

Signup and view all the flashcards

Why is apoptosis important?

Apoptosis is a controlled process that eliminates unwanted or damaged cells without triggering inflammation. It's essential for development, tissue homeostasis, and eliminating harmful cells.

Signup and view all the flashcards

Why is Necrosis problematic?

Necrosis is a form of cell death that arises from irreversible injury. It disrupts tissue integrity, triggers inflammation, and can be harmful.

Signup and view all the flashcards

What triggers Apoptosis?

Apoptosis is triggered by signals, such as withdrawal of growth factors, DNA damage, or the accumulation of misfolded proteins. These signals activate specific pathways leading to the cell's self-destruction.

Signup and view all the flashcards

What is 'the decision to activate the pathway' in apoptosis?

The decision to activate the apoptotic pathway involves complex signaling events that assess the cell's health and trigger the necessary cascade of events.

Signup and view all the flashcards

What happens during 'the actual 'suicide' of the cell' in apoptosis?

The 'suicide' of the cell involves a series of events: activation of caspases, breakdown of the cytoskeleton, and the formation of apoptotic bodies, leading to the cell's dismantling.

Signup and view all the flashcards

What happens during 'engulfment of the cell remains' in apoptosis?

Phagocytes engulf apoptotic bodies, breaking them down in a controlled process and preventing inflammation. This ensures the removal of cellular debris without causing damage.

Signup and view all the flashcards

Caspases

A family of proteases (enzymes that break down proteins) that play a key role in programmed cell death (apoptosis).

Signup and view all the flashcards

Caspase activation

Activation of caspases occurs through proteolytic cleavage, meaning they are activated by being cut by another protease.

Signup and view all the flashcards

Extrinsic apoptotic pathway

The extrinsic pathway of apoptosis is initiated when death receptors on the cell surface are activated by their respective ligands.

Signup and view all the flashcards

Intrinsic apoptotic pathway

The intrinsic pathway of apoptosis is triggered by internal stress signals, such as DNA damage, leading to mitochondrial dysfunction.

Signup and view all the flashcards

Ligands and death receptors in the extrinsic pathway

FasL (Fas ligand) binds to Fas (CD95) receptor, TNF (tumor necrosis factor) binds to TNF-R (TNF receptor), and TRAIL (TNF-related apoptosis-inducing ligand) binds to DR4 (Trail-R) receptor, triggering apoptosis.

Signup and view all the flashcards

Ligand-induced cell death

The process of apoptosis initiated by ligand-receptor interactions involves the formation of a death-inducing signaling complex (DISC) where effector caspases, like caspase 8, are activated.

Signup and view all the flashcards

Mitochondrial pathway of apoptosis

The intrinsic pathway involves mitochondria releasing cytochrome C, which activates caspase 9, which in turn activates downstream caspases, leading to cell death.

Signup and view all the flashcards

Assessing and imaging apoptosis

Apoptosis can be detected using techniques like flow cytometry, microscopy, caspase assays, and TUNEL staining, which examine changes in nuclear morphology, caspase activity, and DNA fragmentation.

Signup and view all the flashcards

Autophagic cell death

A form of cell death triggered by stress, where the cell essentially 'eats itself' through the formation of autophagosomes.

Signup and view all the flashcards

Apoptosis in Development

Apoptosis plays a vital role in embryo development, removing unwanted cells, for example, during limb formation.

Signup and view all the flashcards

Apoptosis in Immune System

Apoptosis helps to regulate the immune system by eliminating faulty or harmful immune cells.

Signup and view all the flashcards

Apoptosis and Cancer

Defects in apoptosis are linked to cancer development, allowing damaged cells to proliferate uncontrollably.

Signup and view all the flashcards

Necroptosis in Disease

Necroptosis is implicated in various diseases, including stroke, neurodegenerative diseases like Alzheimer's.

Signup and view all the flashcards

Autophagy: Cellular Recycling

Autophagy is a protective mechanism in times of stress, allowing the cell to recycle components for survival.

Signup and view all the flashcards

Oncogene

A gene that when mutated or overexpressed can cause uncontrolled cell growth and proliferation, leading to cancer.

Signup and view all the flashcards

Tumor Suppressor Gene

A normal gene that regulates cell growth and division. When mutated, this gene can lose its ability to suppress cancer development.

Signup and view all the flashcards

p53 (Tumor Suppressor Protein)

A protein that plays a key role in regulating the cell cycle and preventing tumor formation. It can detect DNA damage and initiate repair or apoptosis.

Signup and view all the flashcards

Growth Factor

A signaling molecule that promotes cell growth and proliferation. It can bind to receptors on the cell surface and trigger signaling pathways.

Signup and view all the flashcards

Survival Factor

A signaling molecule that promotes cell survival and prevents apoptosis. It can bind to receptors on the cell surface and activate pathways that block cell death.

Signup and view all the flashcards

Telomeres

Protective caps at the ends of chromosomes. They shorten with each cell division, contributing to cell aging.

Signup and view all the flashcards

Study Notes

Cell Death & Apoptosis Overview

  • Cell death is crucial for maintaining a constant number of cells.
  • Two main forms: apoptosis (programmed cell death) and necrosis (killing/decay).
  • Apoptosis is a controlled process, avoiding damage to surrounding cells.
  • Necrosis is uncontrolled, causing cell leakage and inflammation.

Apoptosis in Development & Diseases

  • Apoptotic cell death is a common process during embryonic development.
  • In adult multicellular organisms, billions of healthy cells are lost via apoptosis every hour.
  • Apoptosis is crucial for development and regulation, eliminating cells that don't meet criteria.
  • Defects in apoptotic pathways can lead to diseases.

Apoptosis Objectives

  • Understanding cell death pathways is a key objective.
  • Determining how to assess cell death is also important.
  • The physiological aspects of apoptosis need to be understood.
  • How defects in apoptotic pathways correlate with diseases is another aspect.

Types of Cell Death: Apoptosis vs. Necrosis

  • Apoptosis is programmed cell death.
  • Necrosis is cell death due to injury.
  • Apoptosis is a tidy process with no inflammation.
  • Necrosis is messy involving inflammation and damage to surrounding cells.

Apoptosis Morphology and Biochemistry

  • Morphological changes in apoptosis involve cell shrinkage, chromatin condensation, and apoptotic body formation.
  • Biochemical changes in apoptosis include caspase activation and endonuclease activation.

Apoptosis Pathways

  • Two main pathways regulate cell death: intrinsic and extrinsic.
  • Extrinsic pathway utilizes death receptors and signals.
  • Intrinsic pathway involves mitochondrial events and signals.

Identifying and Assessing Apoptosis

  • Several methods can identify apoptotic cells.
  • Techniques include nuclear staining, DNA fragmentation detection (TUNEL staining), and single-cell electrophoresis (Comet assay).

Apoptotic Changes and Processes

  • Caspases - crucial protease enzymes in apoptosis, breaking down cellular components to tidy up.
  • Genes playing roles in cancer development include oncogenes, tumor suppressor genes, and DNA repair genes

Importance of Apoptosis

  • Essential for normal physiology and development
  • Critical for processes like immune system maturation and neural development in adults.
  • Plays a role in processes like immune privilege and wound repair.
  • Excess apoptosis can lead to diseases like neurodegenerative disorders and cardiac infarction.
  • Insufficient apoptosis can lead to diseases like cancer and autoimmunity.

Other Forms of Cell Death

  • Autophagy - a cellular process where cells recycle their own components
  • Necroptosis – a programmed form of necrotic cell death
  • Other forms of cell death exist in normal and pathological conditions.

Cancer and Apoptosis

  • Evasion of apoptosis is a common feature of cancer cells, allowing uncontrolled cell growth.
  • Activating apoptosis in cancer cells is a promising area of cancer treatment.
  • Cancer is a genetic disease with mutations driving uncontrolled cell proliferation.

Cancer Treatment/Therapies

  • Treatments aim to target specific molecules or pathways crucial for excessive cell growth.

Promising Cancer Targets

  • Several cellular regulators and signaling components (e.g. HER2 and STI-571) are promising cancer treatment targets.

Apoptosis and Cell Death

  • Apoptosis and cell death are related but distinct processes.
  • In apoptosis, the cell actively destroys itself, while necrosis is often due to injury.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Apoptosis in Development & Diseases PDF

Description

This quiz explores the process of apoptosis, particularly in the context of tadpole tail development and its crucial role in the immune system. It contrasts apoptosis with necrosis, discussing cellular impacts and energy requirements. Test your understanding of the features and implications of programmed cell death.

More Like This

Apoptosis y Piroptosis
13 questions

Apoptosis y Piroptosis

SelectivePascal avatar
SelectivePascal
Cell Death and Apoptosis Overview
45 questions

Cell Death and Apoptosis Overview

sunhwasoo avatar
sunhwasoo
Apoptosis and Cell Death Quiz
38 questions

Apoptosis and Cell Death Quiz

BreathtakingBinary924 avatar
BreathtakingBinary924
Immunity and Cell Death Quiz
8 questions

Immunity and Cell Death Quiz

UndisputedStrait avatar
UndisputedStrait
Use Quizgecko on...
Browser
Open
Browser
Browser