Activating Prior Knowledge 1 2 3 4 5

Activating Prior Knowledge: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. List the eight characteristics of living things. List four differences between plant and animal cells. Which animal organelle is used in cell division? Which organelle surrounds the cell membrane in plant cells? What do we call the jelly-like material within the cell? What are chromosomes made of? Where are chromosomes found in your cell (organelle)? How many chromosomes are found in each human body cell? Where did YOUR chromosomes come from? Can you name five types/kinds of cells found in the human body? Name three differences between prokaryotic and eukaryotic cells. Click on a lesson name to select.

Do you remember any of the eight characteristics of living things? 1. Living things are based on a universal genetic code (DNA) 2. Living things grow and develop 3. Living things respond to their environment (stimulus) 4. Living things reproduce 5. Living things maintain a stable internal environment (homeostasis) 6. Living things obtain and use material and energy (metabolism) 7. Living things are made up of CELLS 8. Taken as a group, living things evolve over time Click on a lesson name to select.

Plant vs. Animal • Cell wall and cell membrane • Large central vacuole • Chloroplast (photosynthesis) and mitochondria (cellular respiration) • Only a cell membrane • Smaller vacuoles • Only mitochondria (cellular respiration) • Lysosomes • Flagella • Centrioles – used in cell division Click on a lesson name to select.

Chromatin and Chromosomes: • Inside the nucleus are fine strands of chromatin = a complex of DNA bound to protein • Chromatin coil up and become densely packed, forming chromosomes – Chromosomes are visible under a microscope when a cell divides Click on a lesson name to select.

Number of chromosomes in a human body cell? 23 pairs of chromosomes = 46 chromosomes total 23 from mom and 23 from dad Click on a lesson name to select.

WHERE ARE CHROMOSOMES IN EUKARYOTIC CELLS? CYTOPLASM NUCLEUS Click on a lesson name to select.

Types of Cells in the body: • Cells - basic unit of structure and function in living things • Cells with a specific structure and function and are found in multi-celled organisms • Examples: skin cells, blood cells, brain cells, bone cells, liver cell, nerve cells, muscle cells, etc. Brain cells Blood Click oncells a lesson name to select. Liver cells

Two categories of cells Prokaryotic -No Nucleus -Less complex Eukaryotic -Nucleus -Unicellular -Complex -Cell wall (plants and bacteria) -Membrane bound organelles -Multicellular -Smaller Ribosomes -Cell membrane less complex -DNA - Ribosomes larger -Cytoplasm and complex -DNA is circular -Ribosomes -DNA is X shaped -Living things 0. 1 -10µm 10 -100µm Click on a lesson name to select.

Vocabulary: • Asexual Reproduction • Sexual Reproduction • Mitosis • Meiosis • Diploid • Haploid • • • Chromatin Chromatid Centromere Histone Nucleosomes Click on a lesson name to select.

Asexual Reproduction: • The production of genetically identical offspring from a single parent Click on a lesson name to select.

Sexual Reproduction: • Offspring are produced by the fusion of two sex cells – one from each of two parents. These fuse into a single cell before the offspring can grow. Click on a lesson name to select.

Mitosis: • Division of the nucleus of a eukaryotic cell • Followed by cytokinesis – division of the cytoplasm • The two daughter cells are identical to the original cell Click on a lesson name to select.

Meiosis: • Process that produces gametes from a diploid cell. A reductive division of the nucleus that produces four haploid gametes. Click on a lesson name to select.

Diploid: • Cells having two sets of chromosomes – 2 N = 46 – Examples: All human body cells • Except reproductive cells (sperm and egg) Click on a lesson name to select.

Haploid: • Cells containing only one set of chromosomes – N = 23 – Gametes (egg and sperm) Click on a lesson name to select.

Chromatin: • DNA and protein (histones) in the nucleus of a non-dividing cell Click on a lesson name to select.

Chromatid: • One of the two identical parts of a replicated chromosome Click on a lesson name to select.

Centromere: • Point of attachment between sister chromatids Click on a lesson name to select.

Histone: • Protein molecule that DNA wraps around during chromosome formation Click on a lesson name to select.

Cellular Reproduction Section 1: Cellular Growth Section 2: Mitosis and Cytokinesis Section 3: Cell Cycle Regulation Click on a lesson name to select.

Nucleosomes: • The beadlike structures formed by DNA and histone molecules Click on a lesson name to select.

Section 1 Cellular Reproduction Cellular Growth Ratio of Surface Area to Volume

Section 1 Cellular Reproduction Cellular Growth § As the cell grows, its volume increases much more rapidly than the surface area. § The cell might have difficulty supplying nutrients and expelling enough waste products.

Section 1 Cellular Reproduction Cellular Growth Transport of Substances § Substances move by diffusion or by motor proteins. § Diffusion over large distances is slow and inefficient. § Small cells maintain more efficient transport systems.

Section 1 Cellular Reproduction Cellular Growth Cellular Communications § The need for signaling proteins to move throughout the cell also limits cell size. § Cell size affects the ability of the cell to communicate instructions for cellular functions.

Section 1 Cellular Reproduction Cellular Growth The Cell Cycle § Cell division prevents the cell from becoming too large. § It also is the way the cell reproduces so that you grow and heal certain injuries. § Cells reproduce by a cycle of growing and dividing called the cell cycle.

Section 1 Cellular Reproduction Cellular Growth § Interphase is the stage during which the cell grows, carries out cellular functions, and replicates. § Mitosis is the stage of the cell cycle during which the cell’s nucleus and nuclear material divide. § Cytokinesis is the method by which a cell’s cytoplasm divides, creating a new cell.

Section 1 Cellular Reproduction Cellular Growth The Stages of Interphase § The first stage of interphase, G 1 § The cell is growing, carrying out normal cell functions, and preparing to replicate DNA.

G 0 Phase • Not all cells are continually replicated. • Example: nerve cells, heart cells • Cells enter G 0 from G 1 • Nonreplicating cells are found in G 0 – quiescent (dormant) or senesecent (aging or deteriorating) • Do NOT copy their DNA, do NOT prepare for cell division • Cells may remain quiescent in G 0 for an indeterminate period of time (when no more new cells are needed), only to re-enter G 1 phase and begin dividing again under specific conditions.

Section 1 Cellular Reproduction Cellular Growth The Second Stage of Interphase, S § The cell copies its DNA in preparation for cell division.

Section 1 Cellular Reproduction Cellular Growth The Third Stage of Interphase, G 2 § The cell prepares for the division of its nucleus.

Section 2 Cellular Reproduction Mitosis and Cytokinesis The Stages of Mitosis § Prophase § The chromosomes condense. § Sister chromatids are attached at the centromere. § The longest stage of mitosis § Spindle fibers form in the cytoplasm. § The nuclear envelope seems to disappear. § Spindle fibers attach to the sister chromatids.

Section 2 Cellular Reproduction Mitosis and Cytokinesis Metaphase § Sister chromatids line up in the middle of the cell. § The shortest stage of mitosis

Section 2 Cellular Reproduction Mitosis and Cytokinesis Anaphase § The sister chromatids separate. § The chromosomes move toward the poles of the cell.

Section 2 Cellular Reproduction Mitosis and Cytokinesis Telophase § The chromosomes arrive at the poles and begin to relax. § Two new nuclear membranes begin to form and the nucleoli reappear. § The spindle apparatus disassembles.

Cytokinesis in Animal Cells • In animal cell, cell membrane is drawn in (forming a cleavage furrow) until the cytoplasm is pinched into two equal parts. – Each part contains its own nucleus and organelles.

Cytokinesis in Plant Cells Cell plate forming Wall of parent cell Daughter nucleus – A cell wall then forms in between the two new membranes. TEM 7, 500 • In plants, the cell membrane is not flexible enough to draw inward because of the rigid cell wall. • A cell plate forms between the divided nuclei that develops into cell membranes. Cell wall Vesicles containing cell wall material New cell wall Cell plate Daughter cells

Telophase and Cytokinesis

Section 3: Cell Cycle Regulation

Regulating the Cell Cycle • Cell growth and division are very controlled • True or False – All cells move through the cell cycle at the same rate. – The average human cell cycle is about 20 hours. – Most muscle and nerve cells do not divide once they have developed – Blood, skin and digestive tract cells divide rapidly throughout life

Section 3 Cellular Reproduction Cell Cycle Regulation Normal Cell Cycle Scientists have been trying to determine what regulates the cell cycle. Biologists discovered a protein that when injected into a nondividing cell, a mitotic spindle would form. What is the protein called? cyclin Why? regulates cell cycle Cyclins regulate the timing of the cell cycle in eukaryotic cells.

Cell Cycle

Section 3 Cellular Reproduction Cell Cycle Regulation Quality Control Checkpoints § The cell cycle has built-in checkpoints that monitor the cycle and can stop it if something goes wrong. § Spindle checkpoints also have been identified in mitosis.

Cell Cycle Checkpoints

Section 3 Cellular Reproduction Cell Cycle Regulation Abnormal Cell Cycle: Cancer § Cancer is the uncontrolled growth and division of cells. § Cancer cells can kill an organism by crowding out normal cells, resulting in the loss of tissue function.

Section 3 Cellular Reproduction Cell Cycle Regulation Causes of Cancer § The changes that occur in the regulation of cell growth and division of cancer cells are due to mutations. § Various environmental factors can affect the occurrence of cancer cells.

Section 3 Cellular Reproduction Cell Cycle Regulation Apoptosis § Programmed cell death § Cells going through apoptosis actually shrink and shrivel in a controlled process.

Section 3 Cellular Reproduction Cell Cycle Regulation Stem Cells § Unspecialized cells that can develop into specialized cells when under the right conditions

Section 3 Cellular Reproduction Cell Cycle Regulation Embryonic Stem Cells § After fertilization, the resulting mass of cells divides repeatedly until there about 100– 150 cells. These cells have not become specialized.

Section 3 Cellular Reproduction Cell Cycle Regulation Adult Stem Cells § Found in various tissues in the body and might be used to maintain and repair the same kind of tissue § Less controversial because the adult stem cells can be obtained with the consent of their donor