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Genetic Basis of Embryonic Development
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What a Difference a _______Makes!
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What a Difference a Week Makes!
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I. Embryonic Development Involves 3 interrelated processes: 1
I. Embryonic Development Involves 3 interrelated processes: 1. Cell ________: cells increase in number
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I. Embryonic Development (Fig. 21
I. Embryonic Development (Fig. 21.3) Involves 3 interrelated processes: 1. Cell division : cells increase in number
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I. Embryonic Development (Fig. 21
I. Embryonic Development (Fig. 21.3) Involves 3 interrelated processes: 1. Cell division : cells increase in number 2. Cell __________: cells become “specialized” in __________ & ________
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I. Embryonic Development (Fig. 21
I. Embryonic Development (Fig. 21.3) Involves 3 interrelated processes: 1. Cell division : cells increase in number 2. Cell differentiation: cells become “specialized” in ___________ & ___________
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I. Embryonic Development (Fig. 21
I. Embryonic Development (Fig. 21.3) Involves 3 interrelated processes: 1. Cell division : cells increase in number 2. Cell differentiation: cells become “specialized” in structure & function
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I. Embryonic Development (Fig. 21
I. Embryonic Development (Fig. 21.3) Involves 3 interrelated processes: 1. Cell division : cells increase in number 2. Cell differentiation: cells become “specialized” in structure & function – cells are not ________ distributed but are organized into organs & tissues
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I. Embryonic Development (Fig. 21
I. Embryonic Development (Fig. 21.3) Involves 3 interrelated processes: 1. Cell division : cells increase in number 2. Cell differentiation: cells become “specialized” in structure & function – cells are not randomly distributed but are organized into organs & tissues
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3. _____________: physical process that gives an organism its shape.
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3. Morphogenesis: physical process that gives an organism its shape.
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II. Plant vs. Animal Development 1
II. Plant vs. Animal Development 1. Animal development involves ________ of cells/tissues necessary to transform the embryo.
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II. Plant vs. Animal Development 1
II. Plant vs. Animal Development 1. Animal development involves movement of cells/tissues necessary to transform the embryo. Example: Blastula to Gastrula stage
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When do plants stops growing?
2. Plant development involves _________ growth throughout lifetime (embryonic regions of shoot tips and _____).
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2. Plant development involves continual
2. Plant development involves continual growth throughout lifetime (embryonic regions of shoot tips and _____).
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2. Plant development involves continual
2. Plant development involves continual growth throughout lifetime (embryonic regions of shoot tips and roots).
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What about animals?
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2. Plant development involves continual growth throughout lifetime (embryonic regions of shoot tips and roots). *In animals, growth _____, but cells must be ________ throughout animal’s lifetime
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2. Plant development involves continual growth throughout lifetime (embryonic regions of shoot tips and roots). *In animals, growth stops, but cells must be _______throughout animal’s lifetime.
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2. Plant development involves continual growth throughout lifetime (embryonic regions of shoot tips and roots). *In animals, growth stops, but cells must be replaced throughout animal’s lifetime. Examples:
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2. Plant development involves continual growth throughout lifetime (embryonic regions of shoot tips and roots). *In animals, growth stops, but cells must be replaced throughout animal’s lifetime. Examples: (blood cells, skin cells, cells lining small intestine)
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III. Cell Differentiation & Gene Expression (How is Gene Expression Related to Cell Differentiation?) Different cell types (i.e. _____cells and _____cells) result from differential (_______) gene expression in cells with the same_______.
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III. How is Gene Expression related to Cell Differentiation?
Different cell types (i.e. nerve cells and blood cells) result from differential (_____) gene expression in cells with the same_______.
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III. Cell Differentiation & Gene Expression
Different cell types (i.e. nerve cells and blood cells) result from differential (unique) gene expression in cells with the same____.
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III. Cell Differentiation & Gene Expression
Different cell types (i.e. nerve cells and blood cells) result from differential (unique) gene expression in cells with the same DNA. *Three major mechanisms of differential gene expression: 1. Regulation of _______ synthesis.
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III. Cell Differentiation & Gene Expression
Different cell types (i.e. nerve cells and blood cells) result from differential (unique) gene expression in cells with the same DNA. *Three major mechanisms of differential gene expression: 1. Regulation of protein synthesis.
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1. Regulation of protein synthesis:
____________: Promotor Region controls (AKA: gene __________), mRNA processing (_________), micro RNAs (_______) and small interfering RNAs (________) both interfere with mRNA transcript therefore affect ____________.
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1. Regulation of protein synthesis:
Transcription: Promotor Region controls (AKA: gene __________), mRNA processing (_________), micro RNAs (_______) and small interfering RNAs (________) both interfere with mRNA transcript therefore affect ____________.
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1. Regulation of protein synthesis:
Transcription: Promotor Region controls (AKA: gene switches), mRNA processing (_________), micro RNAs (_______) and small interfering RNAs (________) both interfere with mRNA transcript therefore affect ____________.
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1. Regulation of protein synthesis:
Transcription: Promotor Region controls, mRNA processing (introns), micro RNAs (miRNAs) and small interfering RNAs (siRNAs) both interfere with mRNA transcript therefore affect ______________.
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1. Regulation of protein synthesis: Transcription: Promotor Region controls, mRNA processing (introns), micro RNAs (miRNAs) and small interfering RNAs (siRNAs) both interfere with mRNA transcript therefore affect translation.
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Example of Differential Gene Expression:
Liver Cells & Lens Cells – same DNA Liver cells albumin (_______ protein) Lens cells _________ proteins
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Example of Differential Gene Expression:
Liver Cells & Lens Cells – same DNA Liver cells albumin (blood protein) Lens cells crystallin proteins
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What is the same between these cells?
What is different?
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Both cells have the same DNA & are affected by activators!
Available Activators vary between the cells.
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At the two cell stage: Are the cells genetically identical?
How do cells “know” which genes should be expressed at a certain time during embryonic development? At the two cell stage: Are the cells genetically identical? 2. ____________ _____________– located in the _______ (______, __________, ____________) are unevenly distributed
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At the two cell stage: Are the cells genetically identical?
How do cells “know” which genes should be expressed at a certain time during embryonic development? At the two cell stage: Are the cells genetically identical? 2. Maternal Substances – located in the ____ (______, __________, ____________) are unevenly distributed.
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At the two cell stage: Are the cells genetically identical?
How do cells “know” which genes should be expressed at a certain time during embryonic development? At the two cell stage: Are the cells genetically identical? 2. Maternal Substances – located in the egg (______, __________, ____________) are unevenly distributed.
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At the two cell stage: Are the cells genetically identical?
How do cells “know” which genes should be expressed at a certain time during embryonic development? At the two cell stage: Are the cells genetically identical? 2. Maternal Substances – located in the egg (mRNA, proteins, organelles) are unevenly distributed *Subsequent cells (after fertilization) will receive unequal amounts of these – this leads to____ _____________
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At the two cell stage: Are the cells genetically identical?
How do cells “know” which genes should be expressed at a certain time during embryonic development? At the two cell stage: Are the cells genetically identical? 2. Maternal Substances – located in the egg (mRNA, proteins, organelles) are unevenly distributed *Subsequent cells (after fertilization) will receive unequal amounts of these – this leads to cell differentiation
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Differential Gene Expression
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3. _________ __________– One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called ___________.
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3. Cell-to-cell Communication – One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called ___________.
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3. Cell-to-cell Communication – One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called induction.
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3. Cell-to-cell Communication – One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called induction. *Signals can either be sent through the ________ of one embryonic cell anchoring with ________ sites of another cell or secretory _______ binding to glycoproteins of the receiving cell.
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3. Cell-to-cell Communication – One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called induction. *Signals can either be sent through the glycoproteins of one embryonic cell anchoring with ________ sites of another cell or secretory _______ binding to glycoproteins of the receiving cell.
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3. Cell-to-cell Communication – One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called induction. *Signals can either be sent through the glycoproteins of one embryonic cell anchoring with receptor sites of another cell or secretory _______ binding to glycoproteins of the receiving cell.
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Fig
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3. Cell-to-cell Communication – One embryonic cell can cause changes in nearby embryonic cells through molecular signals – this is called induction. *Signals can either be sent through the glycoproteins of one embryonic cell anchoring with receptor sites of another cell or secretory protein binding to glycoproteins of the receiving cell.
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Fig
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**Overall: A signal molecule sends a cell down a specific ______________ ______by causing a ______ in its gene ____________that results in observable cellular ____________.
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**Overall: A signal molecule sends a cell down a specific developmental path by causing a change in its gene ____________that results in observable cellular ____________.
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**Overall: A signal molecule sends a cell down a specific developmental path by causing a change in its gene expression that results in observable cellular changes.
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Fig
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Fig
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C. Elegans How many cell divisions lead to mature intestinal cells in C. Elegans?
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. ____-______ _________: Mom tells Junior which way is “up” – bicoid gene in Drosophila
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila
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What stage of fruit fly development is this?
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila **What leads to egg polarity?
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila **What leads to egg polarity? Nurse cells produce bicoid protein at the anterior end of the cell. (Maternal substances are unevenly distributed in the egg from the get go)
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila B. ______________ _______: Control where/how many body __________ will form
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila B. Segmentation Genes: Control where/how many body ___________will form
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila B. Segmentation Genes: Control where/how many body segments will form
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila B. Segmentation Genes Control where/how many body segments will form C. ___________ ________ specify the types of appendages /structures that each segment will form.
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila B. Segmentation Genes Control where/how many segments will form C. Homeotic Genes specify the types of appendages /structures that each segment will form. **Species that have a ________ common ancestor tend to have homeotic genes with similar base pair sequences.
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IV. Morphogenesis (Shape & Body Pattern) A
IV. Morphogenesis (Shape & Body Pattern) A. Egg-polarity Genes: Mom tells Junior which way is “up” – bicoid gene in Drosophila B. Segmentation Genes Control where/how many segments will form C. Homeotic Genes specify the types of appendages /structures that each segment will form. **Species that have a close common ancestor tend to have homeotic genes with similar base pair sequences.
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Mutations in homeotic genes can have dramatic physical effects on the organism!
These mutations lead to major __________changes in a short period of time for a species.
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Mutations in homeotic genes can have dramatic physical effects on the organism!
These mutations lead to major phenotypic changes in a short period of time for a species.
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D. Apoptosis (Cell Suicide)
Programmed ____death
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D. Apoptosis (Cell Suicide)
Programmed cell death Triggered by ______molecules that activate a cascade of _______ proteins in the cells that are destined to die.
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D. Apoptosis (Cell Suicide)
Programmed cell death Triggered by signal molecules that activate a cascade of ________proteins in the cells that are destined to die.
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D. Apoptosis (Cell Suicide)
Programmed cell death Triggered by signal molecules that activate a cascade of suicide proteins in the cells that are destined to die.
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D. Apoptosis (Cell Suicide)
Programmed cell death Triggered by signal molecules that activate a cascade of suicide proteins in the cells that are destined to die. Cell death may be necessary for body formation
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Effect of apoptosis during paw development in a mouse
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Apoptosis of a white blood cell (forms lobes & shrinks – lobes are eventually shed as membrane-bound cell fragments
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The role of Ced-9 protein is to ___________Ced-4 activity
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The role of Ced-9 protein is to inhibit
Ced-4 activity
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Activation of Destructive Enzymes
Death Signal CED-9 deactivation CED-3 & 4 Activation Activation of Destructive Enzymes
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6. Compare/Contrast homeotic genes for a mouse and a fruit fly
(Colored Bands)
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