Unit 5 Part B: Day 1 Cell Growth, Division & Reproduction

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1 Name Test Date Period Unit 5 Part B: Day 1 Cell Growth, Division & Reproduction CELL SIZE LIMITATIONS Cells that are will have diffusing materials through the cell. -,, and must enter cell at an efficient rate and cells need to remove from the cell quickly or else they will build up toxins Cytoskeleton the cell organelles Cellular communication and is less efficient DNA will a limit a cell s size If cell is too big then DNA make enough to support the cell Large Cell: It takes for the nutrients to reach the of this cell Smaller Cell: It takes for the same nutrients to reach the of this cell HOW DO CELLS SOLVE THIS PROBLEM? As cell size too much- it can which can lead to of a cell. It is important for cells to stay small so it can properly by materials in & out. ANSWER: before they get too big! CELL CYCLE : Cell Cycle: is the series of events that take place in a leading to its and (replication) that produces daughter. Eukaryotic cells divide via the. Prokaryotic cells divide via.

2 Cell Division in Prokaryotes (no nucleus) Prokaryotes such as divide by the process of. Binary Fission advantages for prokaryotes: Only requires a organism to start Reproduce and increase in population. Less usage Binary Fission disadvantages for prokaryotes: All new cells are (identical) so the only source of genetic variation is Eukaryotic (nucleus) Cell Cycle Process by which a and to produce go through cell division. Cells divide before they become Average cycle for a cell is 22 hours. Cells grow and divide, SO that YOU can grow and reproduce 3 reasons why cells reproduce by asexual (1 parent cell) reproduction: 1. of organism 2. body tissues 3. of old cells What are the TWO main phases of the cell cycle?

3 Interphase: (90%) phase of the cell cycle (G 1, G 0, S, G 2 Phase) State Description Abbreviation Interphase Gap 1 G 1 Gap 0 G 0 cell carries out normal Ribosomes phase division Some cells never leave G O phase ex. cells (once it s gone- it s gone) Some cells never enter G O phase ex. cells (constantly renewed) DNA Replication process by which is to make. Interphase DNA Synthesis S the amount of chromosomes in cell (you must give new cells a copy of ALL the instructions) The growth Gap 2 G 2 cell to (mitosis) cell s are ex. Mitochondria, vacuole, golgi, chloroplast Needed are produced to build. Cell division Mitosis M Prophase, metaphase, anaphase and telophase Division of Cell division Cytokinesis Division on the (2 new cells)

4 Scientists Discovery Year Oswald Avery Discovered that the nucleic acid DNA stores and transmits the genetic information from one generation of an organism to the next Erwin Chargaff Alfred Hershey and Martha Chase Rosalind Franklin James Watson and Francis Crick Discovered a relationship in the nitrogenous bases Adenine (A) = Thymine (T) Guanine (G) = Cytosine (C) Concluded that the genetic material of the bacteriophage was DNA, not protein. Used radioactive phosphorous and sulfur. Took an x-ray of the DNA structure so the patterns could be seen. The x-rays show that DNA is twisted around each other like a helix and has two strands. Watson and Crick proposed that DNA is made up of 2 chains of nucleotides held together by nitrogenous bases & that the 2 strands are twisted together in a shape called a double helix. ***SYNTHESIS (S) PHASE REVISITED*** FUNCTION (JOB) OF DNA: The master copy of an organism s information code that contains the ( ) to make how an organism looks and acts ( ) A is a of that codes for a. Each unique gene has a unique of. This unique sequence of bases will for the production of a unique protein. It is these proteins and combination of proteins that give us different. DNA STRUCTURE (HOW DOES DNA LOOK?) The looks like a twisted and is called a.

5 A molecule of DNA is of millions of tiny ( ) called. DRAW AND LABEL THE 3 PARTS OF NUCLEOTIDE Each nucleotide has 3 parts: of 4 NUCLEOTIDES The ( ) & ( ) form the of the DNA molecule The ( ) form the of the DNA molecule. There are types of _ ( ) The bases are held together by _. NITROGEN BASES Each base will only bond with one other specific base held together with hydrogen bonds. (purine) pairs with (pyrimidine) Apples go in a Tree (pyrimidine) pairs with (purine) Cars go in a Garage A = T form a BASE PAIR C = G form a BASE PAIR According to Erwin Chargaff- If there are 5 A s, how many T s are there? If there are 82 G s, how many C s are there? Because of this, the order of the bases in one strand determines the order of the bases in the other strand. Write the complementary strand of DNA to the following sequence. 5 A G G - C T C - A A G - T C C - T A G 3 DNA REPLICATION (TO COPY) DNA has to be before can be made in. DNA Replication happens during the or Synthesis Phase of the cell cycle All have to be a complete set of instructions!

6 Without, new would NOT have all instructions & the organism will not. Replication is - (one strand is old, one strand new) This is to help (mutations) in DNA. START with Original DNA (Parent Strand) STEPS OF DNA REPLICATION (TO COPY) Step 1: Separation of strands. DNA has to and. DNA in the (weak hydrogen bonds). is the enzyme speeds the of bonds. Step 2: Base pairing & Bonding of bases The free in the will to bases to the exposed. Remember bases bond A=, =G. Free continue to until the entire double strand of DNA has been is the enzyme that builds and the nucleotides DNA is made out of an original strand with a new strand. This is called semi-conservative. Step 3: Results of replication. Replication produces molecules of DNA. Parent New New Parent The polymers will twist back up. Now can be made! Sequence the follow pictures in order of DNA replication.

7 **BACK TO CELL CYCLE M Phase Mitosis and Cytokinesis M Phase: phase of cell cycle (Mitosis and Cytokinesis) A cell to produce two daughter cells that are to the parent cell. Daughter cells have the number of as the cell MITOSIS is divided into phases 1) Prophase move to the opposite sides Spindle form Visible ( ) Nuclear envelope Cell Membrane Nuclear envelope down are held together by a 2) Metaphase Cell Membrane The line up across the (equator) of the cell Sister chromatids are connected to a spindle fiber at its centromere. Sister Chromatid 3) Anaphase Sister chromatids and move from each other. What happens if the chromatids break?

8 4) Telophase TWO The move to opposite sides of the cell. new will form around the sets of chromosomes. Cytokinesis CUT Nuclear envelope reforms Daughter cell Cell membrane inward to create cells Each cell has its with CYTOKINESIS IN PLANT CELLS Daughter cell Cell forms prior to the cell appearing EUKARYOTIC REPRODUCTION: MITOSIS (ASEXUAL) Practice problem: Parent Cell Chromosomes replicate = Cell divides producing 2 identical daughter cells each with (same as parent) Practice problem: Parent Cell has Chromosomes replicate = Cell divides producing 2 identical daughter cells each with

9 Controlling the Cell Cycle/Division Cell and cell are carefully controlled inside an organism. Most and cells do divide once they have developed (G0 phase) Cells that make blood,, and divide throughout life Cell division is controlled by: regulates timing of cell division Regulator including growth factors Apoptosis: when a cell is programmed to Cell Cycle Disorder: CANCER Cancer - the ( ) of cells (cells making more cells) Due to in Cells the to control their growth rate Cells no longer respond to signals that regulate growth of most cells. Cancer cells form of cells called and cause to other cells and tissues a. Benign tumor: does to surrounding healthy tissue b. Malignant tumor: and other tissue (*move) Causes of Cancer: Smoking Radiation exposure Defective genes Viral infections Treatment of cancer Surgery Radiation Chemotherapy

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