Chapter 1. Biology and You

Transcription

1 Midterm Review

2 Chapter 1 Biology and You

3 7 Characteristics of Living Things 1. Cellular organization 2. Reproduction 3. Metabolism 4. Homeostasis 5. Heredity 6. Responsiveness 7. Growth & development.

4 Levels of Organization in Living Things 1. Organelles 2. Cells 3. Tissues 4. Organs 5. Organ system 6. Organism

5 Science vs. Biology Science Process of thinking & learning about the world Biology Study of life

6 Steps of the Scientific Method 1. State the problem based on observations. 2. Research the problem. 3. Form a hypothesis. 4. Test the hypothesis (experiment). 5. Collect and analyze the data. 6. Form a conclusion. 7. Report the results.

7 Control vs. Variable Control The standard of comparison for the experimental group Receives no experimental treatment Variable The one factor that differs among the test groups. Part of the experimental group

8 Independent vs. Dependent Variable Independent variable factor changed by the experimenter (the factor tested) - a good experiment tests one variable. Dependent variable factor that depends on the value of the independent variable (a result measured).

9 Independent vs. Dependent Variable

10 Observations Qualitative Observations that deal with the characteristics of the object such as hardness, texture, beauty, etc. Quantitative Observations that deal with numbers such as the mass, how many, how long, etc.

11 Theory vs. Hypothesis vs. Theory Prediction A set of related hypotheses that have been tested and confirmed many times by many scientists. Unites and explains a broad range of observations. Hypothesis An educated guess based on observations & research that can be tested. Prediction Expected outcome of a test assuming the hypothesis is correct.

12 Base Units of the Metric System Meter Measures length Liter Measures volume Gram Measures mass Celsius Measures temperature

13 Chapter 6: Chromosomes & Cell Reproduction Section 1: Chromosomes

14 Chromosomes Chromosomes are DNA & its associated proteins. We have 46 chromosomes or 23 pairs of chromosomes. In a prokaryotic cell, it is the main ring of DNA.

15 Autosomes vs. Sex Chromosomes Autosomes are any chromosomes that are not directly involved in determining the sex of an individual. We have 22 pairs. Sex chromosomes contain genes that will determine the sex of the individual. We have one pair. Females are XX. Males are XY.

16 Gametes Gametes are an organism s reproductive cells. Female s gametes are eggs or ova. Male s gametes are sperm.

17 Haploid vs. Diploid Haploid refers to a cell (gamete) that contains only 1 set of chromosomes. It is represented by n. Diploid refers to a somatic or body cell that contains 2 sets of chromosomes. It is represented by 2n.

18 Karyotype A karyotype is a photo of the chromosomes in a dividing cell that shows the chromosomes arranged by size. A trisomy at 21 indicates the individual has Down syndrome.

19 Chapter 27 Introduction to Animals

20 General Features of Animals Heterotrophy must consume other organisms Mobility able to perform rapid, complex movements (swim, crawl, walk, run, fly) Multicellularity Diploidy have 2 copies of each chromosome Sexual Reproduction produce gametes which unite.

21 General Features of Animals Absence of a cell wall allows for mobility Blastula formation fertilized egg undergoes cell divisions that form a hollow ball of cells Tissues cells of all animals except sponges are organized into structural and functional units called tissues

22 Primary Tissue Layers of Ectoderm Blastula Gives rise to the outer layer of skin; nervous system; sense organs, such as eyes Endoderm Gives rise to lining of digestive tract; respiratory system; urinary bladder; digestive organs; liver; many glands Mesoderm Gives rise to most of the skeleton; muscles; circulatory system; reproductive organs; excretory organs

23 3 Types of Body Symmetry Asymmetrical irregular in shape ( ex: sponge) Radial symmetry body parts arranged around a central axis; aquatic animals (ex: sea anemone) Bilateral symmetry body design in which there are distinct right and left halves (ex: humans)

24 Cephalization An anterior concentration of sensory structures and nerves Animals with cephalic ends, or heads, are often more active and mobile. It also allows animals to more easily sense food and danger.

25 Phylogenetic Trees A branching diagram Shows how organisms are related through evolution. Clues to a phylogenetic tree come from: Fossil record Comparative anatomy & physiology Comparative embryology Comparing DNA most direct evidence

26 Gastrovascular cavity vs. digestive tract Gastrovascular cavity: One opening No specialization b/c every cell is exposed to all stages of digestion Digestive tract: Two openings a mouth and an anus Food moves in one direction Allows for cell specialization

27 Asexual vs. Sexual Reproduction Asexual Reproduction: Does not involve the fusion of 2 gametes Offspring identical to parent Examples: fragmentation, binary fission & parthenogenesis Sexual Reproduction: Involves the fusion of a male and female gamete Gives rise to genetic variation

28 Levels of Organization Again! Organelle Cell Tissue Organ Organ system Organism

29 Tissue Types and their Functions Epithelial tissue Protects other tissues from dehydration and physical damage Ex: skin; membranes Nervous tissue Carries information throughout the body Ex: brain, spinal cord, nerves

30 Tissue Types and their Functions Connective tissue Support, protect & insulate the body Ex: fat, cartilage, bone, tendons, & blood Muscle tissue Enable the movement of body structures by muscle contraction Ex: skeletal, smooth and cardiac muscle

31 Organ Systems & their Functions Circulatory system transports nutrients, waste, hormones and gases.

32 Organ Systems & their Functions Digestive system Extracts and absorbs nutrients from food; removes waste; maintains water and chemical balances

33 Organ Systems & their Functions Immune system defends against pathogens and disease

34 Organ Systems & their Functions Integumentary system (Skin) Protects against injury, infection and fluid loss; helps regulate body temperature

35 Organ Systems & their Muscular system moves limbs and trunk; moves substances through the body; helps with providing structure and support Functions

36 Organ Systems & their Functions Nervous system regulates behavior; maintains homeostasis; regulates other organ systems; controls sensory and motor function

37 Organ Systems & their Reproductive system produces gametes and offspring Functions

38 Organ Systems & their Respiratory system moves air into and out of the lungs; controls gas exchange between blood and lungs Functions

39 Organ Systems & their Functions Skeletal system protects and supports body organs and produces blood cells

40 Stem Cells Capable of becoming any type of tissue found in the adult body Embryonic stem cells offer the possibility of repairing damaged tissues

41 Chapter 2 Chemistry of Life

42 Atom and Its Parts An atom is the smallest unit of an element that maintains the properties of that element. Nucleus contains: Proton (+) Neutron (Neutral) Electron cloud Electron ( )

43 Covalent vs. Ionic Bonds Covalent Bond Bond formed when atoms share pairs of electrons. Ionic Bond Bond formed by the attraction between oppositely charged ions.

44 Covalent vs. Ionic Bonds

45 Molecules and Polar Molecules Molecule A group of atoms held together by covalent bonds. Polar Molecule Shares its electrons unequally and therefore has partially positive and negative ends, or poles. Water is a polar molecule.

46 Molecules and Polar Molecules

47 Solvents Solvent A substance, usually a liquid, capable of dissolving another substance. Universal Solvent Water.

48 ph Scale and Acids & Bases ph Scale ranges from 0-14 Acid A compound that forms hydrogen ions (H+) in water. Its ph is 0 to less than 7. (0 to < 7) Base A compound that forms hydroxide ions (OH - ) in water. Its ph is greater than 7 to 14. (>7 to 14) Neutral Substances that have a ph of 7.

49 Organic Macromolecules Organic macromolecules: Contain carbon atoms that are covalently bonded to other elements typically hydrogen, oxygen and other carbon atoms. 4 principal classes of organic compounds found in living things are: Carbohydrates Lipids Proteins Nucleic acids

50 Organic Macromolecules Carbohydrates organic compounds made of carbon, hydrogen and oxygen in a 1:2:1 ratio. Monomers are monosaccharides. Ex: Glucose and fructose Polymers are polysaccharides. Ex: Starches, potatoes, paper, crab shells Functions Stores energy. Makes up cell walls in plants and fungi. Makes up exoskeleton in some animals.

51 Organic Macromolecules Lipids are nonpolar molecules that are insoluble in water & include fats, phospholipids, steroids and waxes. Monomers are glycerol & fatty acids Polymer examples Butter & oil All membranes Cholesterol and Steroids Functions Stores energy Makes up cell membranes Acts as chemical messengers

52 Proteins Organic Macromolecules Monomers are amino acids Polymer examples Hemoglobin and antibodies Muscle, hair and nails Functions Hemoglobin carries oxygen and antibodies help defend against infection. Make up tissues that support body structures and provide movement Speed up chemical reactions (enzymes)

53 Organic Macromolecules Nucleic acids Monomers are nucleotides Polymer examples DNA RNA Functions Controls cellular activities Stores hereditary information Plays key role in the manufacture of proteins

54 Catalyst vs. Enzyme Catalyst Speeds up chemical reactions by lowering the activation energy. Enzyme Specialized protein that acts as an organic catalyst.

55 Test Indicators & Positive Results Benedict s solution Tests for simple sugars blue color changes to red, orange, yellow, green. Lugol s iodine Tests for starch reddish orange iodine turns blue-black or black. Biuret solution Tests for protein blue turns purple. BTB (Bromthymol blue) Tests for CO 2 blue turns green, or yellow.

56 Chapter 3 Cell Structure

57 Microscopes Review the different types of microscopes and their uses. Review the parts and functions of a microscope To determine the total magnification of a microscope multiply the eyepiece (ocular lens) times the objective lens.

58 Cell Theory 1. All living things are made of one or more cells. 2. Cells are the basic unit of structure and function in organisms. 3. All cells arise from existing cells.

59 Prokaryote vs. Eukaryote Prokaryote No nucleus No membrane bound organelles Circular DNA Relatively small Reproduce quickly (20 min.) Examples: Bacteria

60 Prokaryote vs. Eukaryote Eukaryote Nucleus Many membrane bound organelles Linear DNA Relatively large Reproduce slowly (24+ hours) Examples: Plants, animals, fungi & protists

61 Cell Parts & Functions Cell membrane Controls what enters & leaves a cell; separates & protects the cell from the environment. Nucleus Contains the DNA in eukaryotic cells; controls cellular activities. Vacuole Membrane bound sac that stores water, may also contain ions, nutrients & waste.

62 Cell Parts & Functions Chloroplast Organelle that uses light energy to make carbohydrates from CO 2 & H 2 O. Cytoplasm Region of the cell within the membrane that includes the fluid, the cytoskeleton and all of the organelles except the nucleus. DNA Material that contains the information that determines hereditary characteristics.

63 Cell Parts & Functions Ribosomes Organelle composed of RNA & protein; site of protein synthesis. Mitochondrion Cell organelle surrounded by 2 membranes & is the site of cellular respiration, which produces ATP. Cell Wall Rigid structure that surrounds the cell membrane & provides support to the cell.

64 Chapter 4 Cells and Their Environment

65 Diffusion vs. Osmosis Diffusion The movement of particles from regions of higher concentration to regions of lower concentration. Ex: perfume spreading across a room. Osmosis The diffusion of water from an area of high concentration to an area of low concentration across a membrane. Ex: Getting thirstier when you drink salt water.

66 Passive vs. Active Transport Passive Transport Does not require energy. Movement down the concentration gradient. Examples: Diffusion Osmosis Facilitated diffusion

67 Passive vs. Active Transport Active Transport Requires energy. Movement against the concentration gradient. Examples: Sodium-potassium pump Endocytosis Phagocytosis Pinocytosis Exocytosis

68 Chapter 6: Chromosomes & Cell Reproduction Section 2: The Cell Cycle Section 3: Mitosis and Cytokinesis

69 5 Stages of the Cell Cycle

70 5 Stages of the Cell Cycle The first 3 stages are collectively called interphase. (90% of a cell s life is spent here.) 1. First growth (G 1 ) phase Cell grows rapidly & carries out routine functions. (Major portion of a cell s life is spent here.)

71 5 Stages of the Cell Cycle 2. Synthesis (S) phase Cell s DNA is copied. Each chromosome consists of 2 chromatids attached at the centromere. 3. Second growth (G 2 ) phase Preparations are made for the nucleus to divide. Microtubules are rearranged. Organelles are manufactured or reproduced.

72 4. Mitosis 5 Stages of the Cell Cycle The nucleus of a cell divides into 2 nuclei each with the same # and kinds of chromosomes as the original cell. 5. Cytokinesis The cytoplasm divides and 2 new cells are formed.

73 3 Checkpoints A checkpoint is an inspection point at which feedback signals from the cell can trigger the next phase of the cell cycle or delay it. 1. Cell Growth (G 1 ) checkpoint at the end of the G 1 phase Makes the decision of whether or not a cell will divide.

74 3 Checkpoints 2. DNA synthesis (G 2 ) checkpoint at the end of the G 2 phase DNA replication is checked by DNA repair enzymes. 3. Mitosis checkpoint at the end of mitosis Triggers the exit from mitosis

75 4 Phases of Mitosis 1. Prophase Chromosomes become visible. Nuclear envelope dissolves. The spindle forms. In animal cells, the centrioles move to opposite poles and the spindle forms between them.

76 4 Phases of Mitosis 2. Metaphase Chromosomes move to the center of the cell & line up along the equator. Spindle fibers link the chromatids of each chromosome to opposite poles.

77 4 Phases of Mitosis 3. Anaphase Centromeres divide. The 2 chromatids (now called chromosomes) move toward opposite poles as the spindle fibers attached to them shorten.

78 4 Phases of Mitosis 4. Telophase A nuclear envelope forms around the chromosomes at each pole. The chromosomes uncoil and return to chromatin form. The spindle dissolves. Cytokinesis begins.

79 Cytokinesis Division of the cytoplasm of a cell Follows the division of the cell s nucleus by mitosis or meiosis Cytokinesis in animal cells occurs when a belt of protein threads pinches the cell membrane in half. Cytokinesis in plant cells occurs when vesicles from the Golgi apparatus fuse to form a cell plate.

80 Cytokinesis Cytokinesis in Cytokinesis in animal cells plant cells

81 Review the following labs: Compound Light Microscope Lab Cell Structure Lab (Lab 9) Diffusion Demo Lab Cell Processes: Osmosis & Diffusion worksheet