Tissues, Organs, and Systems of Living Things UNIT 1 Tissues, Organs, and Systems of Living Things Chapter 1: Cells and More Cells Chapter 2: Plants: From Cells to Systems Chapter 3: Animals: From Cells to Systems

CHAPTER 1 Cells and More Cells In this chapter you will investigate the: similarities and differences between plant and animal cells stages of mitosis and its importance for growth and repair stages of the cell cycle and how it relates to cancer process of cell division in normal and abnormal cells Copyright © 2010 McGraw-Hill Ryerson Ltd.

1.1 Studying the Structure of Cells (Page 7) The development of the microscope in the 1660s increased our understanding of the human body and led to the discovery of cells. Cell – the smallest unit that can perform the functions of life Microscopy – the science of using microscopes to view samples or objects Copyright © 2010 McGraw-Hill Ryerson Ltd.

Bright field/ Dark field Transmission Electron Types of Microscopes (Pages 8-9) Leeuwenhoek Bright field/ Dark field Fluorescence Transmission Electron Phase-contrast Scanning Electron Copyright © 2010 McGraw-Hill Ryerson Ltd.

Cell Structure (Page 10) One of the first structures to be seen clearly through a microscope was the nucleus. The nucleus is the organelle that controls the cell’s activities. Organelles are specialized structures within a cell. Copyright © 2010 McGraw-Hill Ryerson Ltd.

The Cell Theory 2. The cell is the basic organizational unit of life. (Page 11) The Cell Theory was proposed by German scientists in the late 1830s. Theodor Schwann and Matthias Schleiden used their studies of plants and animals to formulate the first two ideas. In 1855 Rudolph Virchow added the final one. The theory states that: 1. All living organisms are made of one or more cells. 2. The cell is the basic organizational unit of life. 3. All cells come from pre-existing cells. Copyright © 2010 McGraw-Hill Ryerson Ltd.

Animal and Plant Cell Organelles (Pages 12-13) Animal Cells Plant Cells The cytosol (the fluid material between the cell membrane and the nucleus) is filled with many specialized organelles. There are some important differences between the organelles found in plant and animal cells. Copyright © 2010 McGraw-Hill Ryerson Ltd.

All Cells Use Energy (Page 14) Cellular Respiration – a process that releases energy from organic molecules, especially carbohydrates such as glucose, in the presence of oxygen Mitochondria – the site in animal and plant cells where cellular respiration takes place Copyright © 2010 McGraw-Hill Ryerson Ltd.

Concepts to be reviewed: Section 1.1 Review (Page 15) Concepts to be reviewed: types of microscopes and their use cell structure The Cell Theory similarities and differences between plant and animal cells cellular respiration Copyright © 2010 McGraw-Hill Ryerson Ltd.

1.2 Genes: Answers and Questions (Page 16) Chromosome – a thread-like structure made mostly of DNA, found in the nucleus of a cell DNA (deoxyribonucleic acid) – material found in the cell nucleus that contains genetic information Gene – a segment of DNA that controls protein production Genome Management Information System, Oak Ridge National Laboratory http://genomics.energy.gov Copyright © 2010 McGraw-Hill Ryerson Ltd.

Genes Direct Protein Production (Page 17) Genome Management Information System, Oak Ridge National Laboratory http://genomics.energy.gov Copyright © 2010 McGraw-Hill Ryerson Ltd.

Genes Direct Protein Production (Page 17) http://genomics.energy.gov Copyright © 2010 McGraw-Hill Ryerson Ltd.

The DNA Code (Pages 17-18) In 1953 scientists James Watson and Francis Crick created this model of DNA (the twisted ladder design is sometimes called a “double helix”). Copyright © 2010 McGraw-Hill Ryerson Ltd.

DNA Screening (Pages 19-20) A karyotype is a micrograph of the chromosomes in a person’s cells. Individual chromosomes from the karyotype can be mapped and then be examined for any irregularities. Chromosome/Gene Map Karyotype http://www.genome.gov/Pages/Hyperion//DIR/VIP/Glossary/Illustration/karyotype.shtml Copyright © 2010 McGraw-Hill Ryerson Ltd.

DNA Screening: Testing for Disorders (Pages 19-20) DNA Screening is the process of testing individuals to determine whether they have the gene or genes associated with a certain genetic disorders PKU (phenylketonuria) – mutation in PAH gene Down Syndrome – trisomy 21 Huntington Disease - mutation in HTT gene Cystic Fibrosis – mutation in the CFTR gene Edwards Syndrome – trisomy 18 Copyright © 2010 McGraw-Hill Ryerson Ltd.

DNA Screening: Testing for Disorders (Pages 19-20) By examining karyotypes some genetic disorders can be seen. Karyotype of a female with Edwards syndrome Karyotype of a female with Down syndrome Copyright © 2010 McGraw-Hill Ryerson Ltd.

Issues Related to DNA Screening ( Pages 19-20 ) DNA testing can reveal genetic disorders (such as Down Syndrome, PKU, Huntington Disease) and can help determine how susceptible a person might be to ailments such as cancers and heart disease. The controversy related to genetic testing revolves around a variety of social issues. (family) - sensitive Genome Management Information System, Oak Ridge National Laboratory http://genomics.energy.gov Copyright © 2010 McGraw-Hill Ryerson Ltd.

Altering Genes / Transgenic Organisms (Pages 22-23) Transgenic Organism – an organism whose genetic information has been altered with the insertion of genes from another species. These organisms are considered to be genetically modified organisms (GMOs). Possible Uses For GMOs Production of non-allergenic human proteins Development of pest resistant crops Increased growth of crops and livestock Concerns Spread of disease from GMOs Negative effects on ecosystems Allergic reactions from eating GMOs Copyright © 2010 McGraw-Hill Ryerson Ltd.

Cloning (Pages 24-25) Cloning – the process of creating identical genetic copies of an organism Pros and Cons of Cloning Pro: Copies are made of “superior” animals. (increased milk & meat production) Con: Clones may be less disease resistant Copyright © 2010 McGraw-Hill Ryerson Ltd.

Mutations ( Pages 26-27 ) Mutation – a change in the DNA of an organism; usual order of base pairs is altered which changes genes and effects the proteins produced. Not all mutations are harmful as they can occur in a non-genetic segments of DNA. Mutagen – a substance or factor that can cause a mutation in DNA; DNA is physically damaged Examples: radiation (X-Rays, UV radiation), mercury, cigarette tar UV mutated skin cells sickle-shaped blood cells albino American alligator Copyright © 2010 McGraw-Hill Ryerson Ltd.

Concepts to be reviewed: Section 1.2 Review ( Page 28 ) Concepts to be reviewed: genetic material in the nucleus: DNA, chromosomes, and genes the structure of DNA DNA screening and related issues issues related to altering genes transgenic organisms cloning mutations Copyright © 2010 McGraw-Hill Ryerson Ltd.

1.3 Cells from Cells (Page 29) Cell Reproduction – the process by which new cells are formed Cells can be produced either asexually (from one parent cell which divides and forms 2 identical daughter cells) or sexually (from two parent cells that each contribute one chromosome from each of their pairs).

Cell Division (Pages 29-30) Most single celled organisms reproduce by splitting in two (binary fission), producing two new identical cells, called daughter cells. In multicellular organisms (such as humans), all body cells (cells produced for growth and repair / replacement) are also produced through this process of splitting in two (binary fission), producing two new cells, called daughter cells.

Mitosis / Cytokinesis and Cell Division (Pages 32-33) The genetic material in the nucleus of a cell divides through a process called mitosis, while the cytoplasm divides by a different process called cytokinesis. Mitosis – the process by which the duplicated contents of the cell’s nucleus divide into two equal parts. Prior to mitosis the DNA in the nucleus must be replicated. Chromatids are single strands of DNA; sister chromatids are two single strands that together make a pair or one chromosome.

DNA Replication (Page 33) DNA Replication – during DNA replication each chromosome is duplicated (creating sister chromatids) with the identical chromatids remaining attached to each other at the centromere Genome Management Information System, Oak Ridge National Laboratory

Stages of Mitosis Stages of Mitosis 1. Prophase 2. Metaphase (Pages 34-36) Stages of Mitosis 1. Prophase Two daughter nuclei are formed. 2. Metaphase 3. Anaphase 4. Telophase DNA is already duplicated Chromatids condense and chromosomes become visible Chromosomes align across the centre equator of the cell. Centromere splits apart the chromatids and chromatids are pulled to each side of the cell by spindle fibres.

Cytokinesis (Pages 37-38) Cytokinesis completes the process of cell division by dividing the rest of the cell (the cytosol and organelles) and begins before telophase is complete. In Animal Cells In plant cells, a cell plate forms in the middle of the cell, eventually becoming a cell wall that divides the cytoplasm in two. This division occurs from the interior outward In animal cells, the middle of the cell contracts, pinching the cell membrane, and the cell is divided. This division occurs from the exterior inward. In Plant Cells

Diffusion (Pages 30-31) Diffusion – the movement of molecules from areas of higher concentration to areas of lower concentration Copyright © 2010 McGraw-Hill Ryerson Ltd.

The Cell Membrane and Diffusion (Pages 30-31) Osmosis – the diffusion of water across a selectively permeable membrane Selectively Permeable Membrane – a membrane through which not all materials can pass; some are kept in and some are kept out Copyright © 2010 McGraw-Hill Ryerson Ltd.

Cell Growth & Limiting Cell Size (Page 32) A major factor limiting cell size is its dependence on diffusion for raw materials and waste removal. The speed of diffusion depends on the difference in concentration between the inside and outside of the cell (the concentration gradient). The ratio of cell membrane surface area (SA) to cell volume (V) is a factor that limits cell size. AS CELLS INCREASE IN SIZE, THE SA/V RATIO DECREASES (making less SA available for diffusion)

Concepts to be reviewed: Section 1.3 Review (Page 39) Concepts to be reviewed: the process of cell division diffusion and osmosis of substances into a cell factors limiting cell size DNA replication the stages of mitosis cytokinesis in animal and plant cells Copyright © 2010 McGraw-Hill Ryerson Ltd.

1.4 The Cell Cycle (Page 40) Cells within the human body have finite life spans. The cell cycle controls the production (through interphase, mitosis, and cytokinesis) of new cells of a variety of different types. Interphase – periods of growth in the life of a cell; consists of two growth stages and a stage of DNA replication

Cell Cycle Checkpoints (Page 41) Cell Cycle Checkpoints – a point in the life of a cell when proteins determine whether cell division should or should not occur

Cell Death and Suicide Cells “die” when they are damaged due to: (Page 42) Cells “die” when they are damaged due to: exposure to toxic chemicals or conditions physical forces the wear and tear of daily use When cells die their contents leaks out and can cause irritation, which can lead to swelling and redness in the surrounding cells Cell “suicide” occurs when the cell experiences a “pre-programmed death” by genes that code for proteins whose duty is to kill the cell in specific situations such as the fetal development of separated fingers and toes “suicide” genes code for proteins that kill the cells in specific situations. cell contents are packaged for use by other cells

Cancer and the Cell Cycle (Pages 43-44) Tumour – an abnormal clump of cells formed when cells divide repeatedly and excessively Cancer – cells with abnormal genetic material that are dividing uncontrollably and can spread to other parts of the body interfering with normal cell functioning

Concepts to be reviewed: Section 1.4 Review (Page 45) Concepts to be reviewed: the stages of the cell cycle the function of cell cycle checkpoints cell death and cell suicide cancer and how it is related to the cell cycle