From 51cb917c0cba89029dc9f9a1ac9c6ffde654823a Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 14:31:13 +0000 Subject: [PATCH 1/7] Cell division expansion --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 78 ++++++++++++++++------ 1 file changed, 56 insertions(+), 22 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index e6a1acf..3dacf5f 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -45,13 +45,13 @@ A person contains roughly 100 trillion cells - Allows **waste products** to leave (removal of waste) - Surrounds and holds other organelles in cell - Interact with outside chemicals (e.g., hormones) -- Must transport food (ATP), nutrients into the cell +- Transports food and nutrients into the cell ### Nucleus - Is the control center of the cell - Holds deoxyribonucleic acid (DNA) in form of `chromatin` - DNA is a double helix containing genes - - `Genes` are a full set of instructions in DNA to make either RNA or a protein, they are **found** in the DNA + - `Genes`: any section of DNA that contain a full set full set of instructions make either RNA or a protein - `Chromatin`: is DNA **wrapped tightly** in protein - `Chromosomes`: are even more tightly wrapped `chromatin` used in cell division only, formed when `DNA` **condenses** in `mitosis` - Surrounded by a double membrane @@ -61,8 +61,8 @@ A person contains roughly 100 trillion cells ### Nucleolus - - Dense region of DNA located in the nucleus (codes `ribosomes`; enzyemes that make protein) - - This area of DNA is specially for ribosomal DNA (rDNA), or DNA used to make ribosomes + - Dense region of DNA located in the nucleus + - This area of DNA is specially for ribosomal DNA (rDNA), or DNA used to code `ribosomes`, organelles that assemble proteins - Produce "large" and "small" subunits of `ribosomes`, which either form complete `ribosomes` in `cytosol` or mix with `endoplasmic reticulum`, forming `rough endoplasmic reticulum` (RER) ### Cytoplasm & Cytosol @@ -124,8 +124,7 @@ A person contains roughly 100 trillion cells ### Centrioles and centrosomes - Made of same protein as `cytoskeleton` - - Important to cell division in animal cells - - Create cilia and flagella (e.g., small hair-like things that swipe dirt out of lungs and tails of sperm, respectively) + - Create and manipulate spindle during mitosis in animal cells ### Lysosomes - Explained before. @@ -140,7 +139,7 @@ A person contains roughly 100 trillion cells - A more stronger, thicker, rigit version of the `cell membrane` - Made of **cellulose** (type of sugar) - Also present in most bacteria, fungi, and protists -- The antibotic **Penicillin** works by destroying the cell walls of bacteria, thereby killing the bateria +- The antibotic **penicillin** works by destroying the cell walls of bacteria, killing it ### Chloroplast - The **solar panel** of the plant cell @@ -158,47 +157,82 @@ A person contains roughly 100 trillion cells ## Cell Division -## Purpose +### Purpose -### 1. Reproduction +#### 1. Reproduction - Single-cellular organisms reproduce via division **asexually** - Multicellular organisms reproduce via combining two germ cells ("sex cells") that contain half the DNA each of two organisms - This is **sexual** -### 2. Growth +#### 2. Growth - Cells have maximum size before transportation of substances within cell becomes **inefficient**, due to **larger cells** decreasing efficiency of `diffusion` - Cells transport chemicals (e.g., nutrients) via `diffusion`, this **limits cell size** - The only way to maintain proper function and get bigger is to **add more cells** -### 3. Repair +#### 3. Repair - **Organisms need to repair cells to stay alive and maintain proper health** - Millions of cells are replaced everyday - Cells naturally die and need to be replaced - e.g., red blood cells, hair cells, skin, injuries, broken bones -## Cell cycle +### Cell cycle - **Interphase** - - **G1** (normal groth and function), + - Large majority of a cell's time is spent in interphase + - **G1**: (normal growth and function), - Prepare for cell divison - - Duplication of DNA **S**, - - Duplication of organelles **G2** + - **S**: Replication of DNA + - **G2**: Replication of organelles + - Checkpoints + - Cells check various things before progressing through various stages in interphase + - Causes of stopping via checkpoints include damaged DNA, not replicated DNA, lack of nutrients for cell growth, and/or signals from other cells - **Mitosis** - Occurs only in eukaryotic cells - - P-MAT: Prophase Prometaphase, Metaphase, Anaphase, Telophase Cytokinesis - - nuclear divison + - P-MAT: Prophase, Metaphase, Anaphase, Telophase + - Division of the nucleus - **Cytokinesis** - **cell division** + - The parent cell splits into two daughter cells - **G0** - - Cell no longer divides - - Outisde of cell cycle + - Cell no longer divides ("cell cycle arrest") + - Outside of cell cycle -### Mitosis +#### Mitosis +- `Chromatid`: Supercoiled DNA, only visible during mitosis, cannot be read without unwinding, similar to compressed zip file +- `Chromosome`: Two identical "sister chromatids" held together in centre by `centromere`, or one sister chromatid after anaphase +- `Centromere`: Proteins sticking sister chromatids - PMAT (prophase, metaphase, anaphase, telophase) +- Division of the nucleus +- Prophase + - Chromatin condenses into two identical `sister chromatids` which condense into `chromosomes` + - Happens to 23 pairs of chromosomes + - Nuclear membrane dissolves + - Centrosomes move to opposite ends (`poles`) of cell, creating `spindle fibres` that begin to attach to `centromeres` in animal cells + - Cell wall organises spindle in plant cell +- Metaphase + - Chromosomes line up in centre of cell to ensure they divide evenly + - Everything in prophase has completed +- Anaphase + - Centromere splits + - Sister chromatids are pulled towards opposite sides of cell via shortening spindle fibres + - Sister chromatids now called `daughter chromosomes` +- Telophase + - Effectively opposite of prophase + - Nuclear membranes form across each of the two nuclei + - Daughter chromosomes unwind into chromatin and are no longer visible + - Nucleolus forms in each nucleus + - Spindle fibres break apart + - **Cytokinesis** usually begins in telophase + - Cell starts to **cleave** (cell centre starts to pinch itself) - +#### Cytokinesis + - Cell division + - Cell splits completely to two daughter cells + - In **animal cells**: Cell membrane pulled inward by cytoskeleton + - **"Pinches in"** along equator of cell, forming **"cleavage furrow"** + - In **plant cells**: Golgi apparatus produces and sends vesicles to centre of plant cell **"cell plate"** to make new cell wall and membrane between daughter cells ## Cell Specialization -- `Zygote`: A one-celled organism formed from the fertilization of an egg by a sperm cell +- `Zygote`: A single-celled organism formed from the fertilization of an egg by a sperm cell - A cell's position in the `gastrula` (outer, middle, inner layer) will determine the fate of the cell, or its potiental. - (LOCATION LOCATION LOCAION!) From 351d0ae98dfb734d9b4637771caf55652ab447a4 Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 14:56:17 +0000 Subject: [PATCH 2/7] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 3dacf5f..ae54afa 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -122,9 +122,13 @@ A person contains roughly 100 trillion cells 1. Centrioles and centrosomes 2. Lysosomes -### Centrioles and centrosomes +### Centrosomes - Made of same protein as `cytoskeleton` - - Create and manipulate spindle during mitosis in animal cells + - **Create and manipulate spindle* during mitosis in animal cells + - One centrosome is a bound pair of two `centrioles` + - Centrioles are present in a few types of plant cells + - Centrioles **create** spindle during mitosis in both plant and animal cells + - Centrioles do not manipulate spindle ### Lysosomes - Explained before. @@ -231,12 +235,15 @@ A person contains roughly 100 trillion cells - In **animal cells**: Cell membrane pulled inward by cytoskeleton - **"Pinches in"** along equator of cell, forming **"cleavage furrow"** - In **plant cells**: Golgi apparatus produces and sends vesicles to centre of plant cell **"cell plate"** to make new cell wall and membrane between daughter cells + ## Cell Specialization -- `Zygote`: A single-celled organism formed from the fertilization of an egg by a sperm cell +- `Zygote`: A single-celled organism formed from the fertilization of an egg by a sperm cell, is a totipotent stem cell - A cell's position in the `gastrula` (outer, middle, inner layer) will determine the fate of the cell, or its potiental. +- Chemical signals from other cells will also determine activated genes that lead to specialisation - (LOCATION LOCATION LOCAION!) +- Specialisation is determined by reading only certain genes ### Stem Cells - They are an **unspecialized** cell that has the potential to become one of several types of cells. -- After cell division, either both can become stem cells or one stays as a stem cell and the other becomes a specialized cell +- Can either divide to two stem cells or - \ No newline at end of file From 688ca4c7351517ebc8a5c3a31a3efc01486b45d3 Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 15:07:53 +0000 Subject: [PATCH 3/7] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index ae54afa..10c32be 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -125,8 +125,8 @@ A person contains roughly 100 trillion cells ### Centrosomes - Made of same protein as `cytoskeleton` - **Create and manipulate spindle* during mitosis in animal cells - - One centrosome is a bound pair of two `centrioles` - - Centrioles are present in a few types of plant cells + - One centrosome is a bound pair of two `centrioles`, one mother and one daughter centriole + - Centrioles are present in very few types of plant cells - Centrioles **create** spindle during mitosis in both plant and animal cells - Centrioles do not manipulate spindle From 8fce0b1074218b023e187fdb5497d457ade266c0 Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 15:19:53 +0000 Subject: [PATCH 4/7] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 10c32be..d611868 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -163,18 +163,18 @@ A person contains roughly 100 trillion cells ### Purpose -#### 1. Reproduction +### 1. Reproduction - Single-cellular organisms reproduce via division **asexually** - Multicellular organisms reproduce via combining two germ cells ("sex cells") that contain half the DNA each of two organisms - This is **sexual** -#### 2. Growth +### 2. Growth - Cells have maximum size before transportation of substances within cell becomes **inefficient**, due to **larger cells** decreasing efficiency of `diffusion` - Cells transport chemicals (e.g., nutrients) via `diffusion`, this **limits cell size** - The only way to maintain proper function and get bigger is to **add more cells** -#### 3. Repair +### 3. Repair - **Organisms need to repair cells to stay alive and maintain proper health** - Millions of cells are replaced everyday - Cells naturally die and need to be replaced @@ -201,7 +201,7 @@ A person contains roughly 100 trillion cells - Cell no longer divides ("cell cycle arrest") - Outside of cell cycle -#### Mitosis +### Mitosis - `Chromatid`: Supercoiled DNA, only visible during mitosis, cannot be read without unwinding, similar to compressed zip file - `Chromosome`: Two identical "sister chromatids" held together in centre by `centromere`, or one sister chromatid after anaphase - `Centromere`: Proteins sticking sister chromatids @@ -229,7 +229,7 @@ A person contains roughly 100 trillion cells - **Cytokinesis** usually begins in telophase - Cell starts to **cleave** (cell centre starts to pinch itself) -#### Cytokinesis +### Cytokinesis - Cell division - Cell splits completely to two daughter cells - In **animal cells**: Cell membrane pulled inward by cytoskeleton From 478d9d918a21969cf8a04bcccd482e12bca482a1 Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 15:55:36 +0000 Subject: [PATCH 5/7] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 39 ++++++---------------- 1 file changed, 11 insertions(+), 28 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index d611868..1ff233f 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -51,7 +51,7 @@ A person contains roughly 100 trillion cells - Is the control center of the cell - Holds deoxyribonucleic acid (DNA) in form of `chromatin` - DNA is a double helix containing genes - - `Genes`: any section of DNA that contain a full set full set of instructions make either RNA or a protein + - `Genes`: any section of DNA that contains a full set of instructions to make either RNA or a protein, **found** in nucleus - `Chromatin`: is DNA **wrapped tightly** in protein - `Chromosomes`: are even more tightly wrapped `chromatin` used in cell division only, formed when `DNA` **condenses** in `mitosis` - Surrounded by a double membrane @@ -62,7 +62,7 @@ A person contains roughly 100 trillion cells ### Nucleolus - Dense region of DNA located in the nucleus - - This area of DNA is specially for ribosomal DNA (rDNA), or DNA used to code `ribosomes`, organelles that assemble proteins + - This area of DNA is specially for ribosomal DNA (rDNA), or DNA used to code `ribosomes`, enzymes that assemble proteins - Produce "large" and "small" subunits of `ribosomes`, which either form complete `ribosomes` in `cytosol` or mix with `endoplasmic reticulum`, forming `rough endoplasmic reticulum` (RER) ### Cytoplasm & Cytosol @@ -124,11 +124,8 @@ A person contains roughly 100 trillion cells ### Centrosomes - Made of same protein as `cytoskeleton` - - **Create and manipulate spindle* during mitosis in animal cells - - One centrosome is a bound pair of two `centrioles`, one mother and one daughter centriole - - Centrioles are present in very few types of plant cells - - Centrioles **create** spindle during mitosis in both plant and animal cells - - Centrioles do not manipulate spindle + - Crucial to mitosis in animal cells + - **Create and manipulate spindle fibres** during mitosis in animal cells ### Lysosomes - Explained before. @@ -207,27 +204,13 @@ A person contains roughly 100 trillion cells - `Centromere`: Proteins sticking sister chromatids - PMAT (prophase, metaphase, anaphase, telophase) - Division of the nucleus -- Prophase - - Chromatin condenses into two identical `sister chromatids` which condense into `chromosomes` - - Happens to 23 pairs of chromosomes - - Nuclear membrane dissolves - - Centrosomes move to opposite ends (`poles`) of cell, creating `spindle fibres` that begin to attach to `centromeres` in animal cells - - Cell wall organises spindle in plant cell -- Metaphase - - Chromosomes line up in centre of cell to ensure they divide evenly - - Everything in prophase has completed -- Anaphase - - Centromere splits - - Sister chromatids are pulled towards opposite sides of cell via shortening spindle fibres - - Sister chromatids now called `daughter chromosomes` -- Telophase - - Effectively opposite of prophase - - Nuclear membranes form across each of the two nuclei - - Daughter chromosomes unwind into chromatin and are no longer visible - - Nucleolus forms in each nucleus - - Spindle fibres break apart - - **Cytokinesis** usually begins in telophase - - Cell starts to **cleave** (cell centre starts to pinch itself) + +| Phase | Diagram | Description | +| :--- | :--- | :--- | +| Prophase | | - Chromatin condenses into two identical `sister chromatids` which condense into `chromosomes`
- Happens to 23 pairs of chromosomes
- Nuclear membrane dissolves
- Centrosomes move to opposite ends (`poles`) of cell, creating `spindle fibres` that begin to attach to `centromeres` in animal cells | +| Metaphase | | - Chromosomes line up in centre of cell to ensure they divide evenly
- Everything in prophase has completed (e.g., nuclear membrane has dissolved completely) | +| Anaphase | | - Centromeres split, separating sister chromatids
- Sister chromatids are pulled towards opposite sides of cell via shortening spindle fibres
- Sister chromatids are now called `daughter chromomsomes` | +| Telophase | | - Effectively opposite of prophase
- Nuclear membranes form across each of the two new nuclei
- Daughter chromosomes unwind into chromatin and are no longer visible
- Nucleolus forms in each nucleus
- Spindle fibres break apart
- **Cytokinesis** usually begins in telophase
- Cells starts to **cleave** (cell centre starts to pinch itself) | ### Cytokinesis - Cell division From f291d1069022c516408b1e3b03cbf9ff85218139 Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 15:59:55 +0000 Subject: [PATCH 6/7] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 1ff233f..d0fea66 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -228,5 +228,5 @@ A person contains roughly 100 trillion cells ### Stem Cells - They are an **unspecialized** cell that has the potential to become one of several types of cells. -- Can either divide to two stem cells or -- \ No newline at end of file +- Can either divide to two stem cells or one stem cell and one specialised cell +- Specialised cells generally do not divide \ No newline at end of file From cb04baf0aecb47acef769eaeaa8e26fa26d5a758 Mon Sep 17 00:00:00 2001 From: Daniel Chen Date: Thu, 7 Nov 2019 16:10:55 +0000 Subject: [PATCH 7/7] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index d0fea66..d795523 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -178,6 +178,9 @@ A person contains roughly 100 trillion cells - e.g., red blood cells, hair cells, skin, injuries, broken bones ### Cell cycle + + + - **Interphase** - Large majority of a cell's time is spent in interphase - **G1**: (normal growth and function), @@ -207,10 +210,10 @@ A person contains roughly 100 trillion cells | Phase | Diagram | Description | | :--- | :--- | :--- | -| Prophase | | - Chromatin condenses into two identical `sister chromatids` which condense into `chromosomes`
- Happens to 23 pairs of chromosomes
- Nuclear membrane dissolves
- Centrosomes move to opposite ends (`poles`) of cell, creating `spindle fibres` that begin to attach to `centromeres` in animal cells | -| Metaphase | | - Chromosomes line up in centre of cell to ensure they divide evenly
- Everything in prophase has completed (e.g., nuclear membrane has dissolved completely) | -| Anaphase | | - Centromeres split, separating sister chromatids
- Sister chromatids are pulled towards opposite sides of cell via shortening spindle fibres
- Sister chromatids are now called `daughter chromomsomes` | -| Telophase | | - Effectively opposite of prophase
- Nuclear membranes form across each of the two new nuclei
- Daughter chromosomes unwind into chromatin and are no longer visible
- Nucleolus forms in each nucleus
- Spindle fibres break apart
- **Cytokinesis** usually begins in telophase
- Cells starts to **cleave** (cell centre starts to pinch itself) | +| Prophase | | - Chromatin condenses into two identical `sister chromatids` which condense into `chromosomes`
- Happens to 23 pairs of chromosomes
- Nuclear membrane dissolves
- Centrosomes move to opposite ends (`poles`) of cell, creating `spindle fibres` that begin to attach to `centromeres` in animal cells | +| Metaphase | | - Chromosomes line up in centre of cell to ensure they divide evenly
- Everything in prophase has completed (e.g., nuclear membrane has dissolved completely) | +| Anaphase | | - Centromeres split, separating sister chromatids
- Sister chromatids are pulled towards opposite sides of cell via shortening spindle fibres
- Sister chromatids are now called `daughter chromomsomes` | +| Telophase | | - Effectively opposite of prophase
- Nuclear membranes form across each of the two new nuclei
- Daughter chromosomes unwind into chromatin and are no longer visible
- Nucleolus forms in each nucleus
- Spindle fibres break apart
- **Cytokinesis** usually begins in telophase
- Cells starts to **cleave** (cell centre starts to pinch itself) | ### Cytokinesis - Cell division