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Characteristics of Life A. Use Energy (the ability to do work) to grow B. Metabolism – maintain complex chemical reactions C. Homeostasis – maintain stable internal environment D. Respond to stimuli – sense organs E. Reproduce – pass genes on to next generation
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Energy Utilization - Organisms take in energy and transform it to do many kinds of work. This fish obtains fuel from the sea urchin and uses energy stored in the molecules of its food to power swimming and other work.
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Metabolism - This protein cascade is an example of the chemical reactions that take place in organisms. The product of one reaction becomes a catalyst for a second reaction.
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Homeostasis – regulatory mechanisms maintain an organism’s internal environment within tolerable limits, even though the external environment may fluctuate. In this example, regulation of the amount of salt flowing through the seagull’s body fluids is controlled by glands on the bill that excrete excess ions.
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Respond to stimuli – When threatened this squid will change colors in order to blend in with it’s surroundings
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Reproduce – Organisms reproduce their own kind. Life comes only from life. This humpback whale protects its offspring.
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I. Building Blocks of Life A. Major macromolecules – composed mostly of carbon, hydrogen, oxygen, nitrogen, phosphorus 1. Water is not a macromolecule but composes approx. 2/3 of living organisms 2/3 of living organisms 2. Carbohydrates – sugars & starches a. Energy – energy extracted from carbs. during cellular respiration is carbs. during cellular respiration is used to produce ATP. used to produce ATP. b. Structural – cellulose, cell wall of plants; chitin, exoskeleton of insects plants; chitin, exoskeleton of insects & arthropods & arthropods
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Chitin a structural carbohydrate
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I. Building Blocks of Life 3. Proteins – most varied & complex organic molecules a. 20 amino acids are building blocks of all proteins all proteins b. Structural proteins – found in cell membranes, muscles (actin/myosin) membranes, muscles (actin/myosin) c. Functional – enzymes (speed up reactions but are not changed by reactions but are not changed by reactions reactions d. Chemical messengers – hormones, made in one part of the body but made in one part of the body but affect another part affect another part
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Muscles are mostly made up of proteins.
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I. Building Blocks of Life 4. Lipids – water insoluble, fats, oils, waxes a. Major component of cell membrane b. Energy stores c. Retards evaporation d. Buoyancy – marine mammals, birds e. Hormones – cholesterol; estrogen, testosterone testosterone
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Phospholipid Bilayer
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Blubber
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I. Building Blocks of Life 5. Nucleic Acids a. DNA, RNA – genetic material genetic material
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B. Fuel of Life – 1. ATP – energy molecule that is used in chemical reactions chemical reactions 2. Photosynthesis – Fig. 4.4 – Process by which the energy from sunlight is used which the energy from sunlight is used to covert low energy inorganic compounds to organic to covert low energy inorganic compounds to organic compounds compounds a. 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 b. Light energy (photons) are captured by photosynthetic pigments, by photosynthetic pigments, chlorophyll a is primary pigment chlorophyll a is primary pigment c. Autotrophs – make own food heterotrophs – must obtain energy from heterotrophs – must obtain energy from outside sources outside sources I. Building Blocks of Life
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Photosynthesis
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3. Respiration - Fig. 4.6 – process in which 3. Respiration - Fig. 4.6 – process in which organic compounds are broken down to organic compounds are broken down to in order to release energy in order to release energy a. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 36ATP a. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 36ATP b. Energy recycles – Fig. 4.5 b. Energy recycles – Fig. 4.5 i. Aerobic respiration – requires O 2 O 2 ii. Anaerobic respiration – no O 2 required required 4. Primary Productivity – net gain in organic matter results when the rate of photosynthesis is greater than the rate of respiration
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Cellular Respiration
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II. Living Machinery Organic molecules are organized into structural & functional units Molecules organelles cells tissues organ systems organism populations communities ecosystems A. Cells & Organelles – the cells is the smallest unit of life, organelles within the cells are specialized for particular tasks
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II. Living Machinery 1. Prokaryotic cells – Fig. 4.7 Lack a membrane bound nucleus & membrane Lack a membrane bound nucleus & membrane bound organelles(ex - bacteria), have genetic bound organelles(ex - bacteria), have genetic material; photosynthesis or chemosynthesis material; photosynthesis or chemosynthesis takes place on the cell membrane; have a cell wall; some have flagellum for locomotion takes place on the cell membrane; have a cell wall; some have flagellum for locomotion
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Prokaryotic Cell
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II. Living Machinery 2. Eukaryotic cells – Fig. 4.8 Have a membrane bound nucleus and Have a membrane bound nucleus and organelles organelles a. Nucleus – control center a. Nucleus – control center b. Endoplasmic reticulum (ER) – b. Endoplasmic reticulum (ER) – packages organic molecules packages organic molecules c. Golgi complex – packages & ships c. Golgi complex – packages & ships d. Mitochondria – site of cell resp. d. Mitochondria – site of cell resp.
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II. Living Machinery e. Chloroplasts – site of photo. f. Cell wall – protects g.Cell membrane – regulates what enters & leaves the cell B. Levels of Organization – Table 4.1
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Eukaryotic Cell - Animal
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Eukaryotic Cell - Plant
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Challenges of Life in the Sea Organisms have evolved numerous adaptations that allow them to live in a wide variety of habitats – Must maintain homeostasis - planktonic – drift with currents - planktonic – drift with currents - benthic – live at the bottom of ocean - benthic – live at the bottom of ocean - nekton – organisms that can swim - nekton – organisms that can swim
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Challenges of Life in the Sea planktonic Benthic nekton
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Challenges of Life in the Sea A. Salinity – avg. 35% - most organisms must maintain lower body salt concentration than ocean 1. diffusion – movement of molecules down their concentration gradient; no energy required; osmosis – diffusion of water 1. diffusion – movement of molecules down their concentration gradient; no energy required; osmosis – diffusion of water 2. osmoconformers – organisms that do not actively maintain salt and water balance, their internal concentrations change as salinity of water changes 2. osmoconformers – organisms that do not actively maintain salt and water balance, their internal concentrations change as salinity of water changes
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Challenges of Life in the Sea 3. osmoregulators – control the concentration of their 3. osmoregulators – control the concentration of their internal environment internal environment 4. hypotonic – a solution that has a lower 4. hypotonic – a solution that has a lower concentration of solutes that that of a cell placed concentration of solutes that that of a cell placed into it; therefore water moves into the cell causing it into it; therefore water moves into the cell causing it to burst to burst isotonic – concentration of solutes and water equal isotonic – concentration of solutes and water equal that of the cell, therefore no net movement of water that of the cell, therefore no net movement of water hypertonic – a solution that has a higher solute hypertonic – a solution that has a higher solute concentration than that of a cell placed into it, concentration than that of a cell placed into it, therefore water moves out of the cell therefore water moves out of the cell
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Challenges of Life in the Sea
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5. Marine fish – have a lower salt concentration than seawater, therefore tend to loose water; adaptations to maintain homeostasis include (Fig. 4.14) Drinks seawater Drinks seawater Excretes excess salt through gills Excretes excess salt through gills Excretes small volumes of concentrated salty urine Excretes small volumes of concentrated salty urine
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Challenges of Life in the Sea 5. Fresh water fish – higher salt concentration that fresh water, therefore tend to gain water; adaptations to maintain homeostasis include Does not drink water Does not drink water Salt absorbed by gills Salt absorbed by gills Excretes large volumes of dilute urine Excretes large volumes of dilute urine
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Challenges of Life in the Sea 6. Adaptations of other marine organisms Sea turtles/sea gulls/sea lions have glands near the eyes that excrete “salty” tears (Fig. 4-15) Sea turtles/sea gulls/sea lions have glands near the eyes that excrete “salty” tears (Fig. 4-15) Mangroves/spartina grass – excrete excess salt through leaves Mangroves/spartina grass – excrete excess salt through leaves Salt crystals on spartina grass
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Challenges of Life in the Sea B. Temperature – most metabolic reactions proceed faster at higher temps. (up to a point) 1. Terms to describe temp. of body a. Poikilothermy – having a body temp. that changes with that of the environment changes with that of the environment b. Homeothermy – maintenance of a constant high body temp. & metabolic rate high body temp. & metabolic rate 2. Terms to describe where the body heat comes from 2. Terms to describe where the body heat comes from a. Ectotherm – an animal that must use environmental energy and behavioral adaptations environmental energy and behavioral adaptations to regulate body temp. to regulate body temp. b. Endotherm – an animal that uses metabolic energy to maintain a constant body temp. to maintain a constant body temp.
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Challenges of Life in the Sea Angel Fish – poikilotherm, exothermic Walrus – homeotherm, endothermic
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Challenges of Life in the Sea c. Surface area to volume ration – determines how rapidly heat and materials flow in & out of organisms (Fig. 4.17) - larger organisms have smaller SA/V than smaller organisms - smaller organisms can rely on diffusion alone - larger organisms must rely on well developed respiratory; circulatory, and digestive systems
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Challenges of Life in the Sea
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IV. Perpetuating Life A. Modes of reproduction 1. Asexual – offspring are genetically identical to parent parent a. Binary fission – bacteria and some fungi; division of parent cell into 2 equal daughter division of parent cell into 2 equal daughter cells cells b. Budding – sea anemone; division of parent cell into 2 unequal daughter cells into 2 unequal daughter cells
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IV. Perpetuating Life Binary fission in a bacterium Budding in yeast
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2. sexual – offspring are genetically unique unique a. Gametes (sex cells) are formed by meiosis formed by meiosis (reduction division) (reduction division) b. Fertilization – fusion of gametes to produce a zygote gametes to produce a zygote c. Zygote divides to produce embryo embryo IV. Perpetuating Life
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B. Reproductive Strategies 1. external fertilization/external development; fishes & frogs fishes & frogs - parents don’t help - large numbers of egg & sperm released - death from disease/predation is high IV. Perpetuating Life
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2. internal fertilization/external development; birds/reptiles birds/reptiles - sometimes parents raise young - smaller brood sizes than fish/amp. - lower death rate than fish/amp. 3. internal fertilization/internal development; some fish/mammals fish/mammals - parents play very active role in raising young - small litters - higher survival rate IV. Perpetuating Life
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External fertilization – External Development
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IV. Perpetuating Life Internal fertilization – External development
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IV. Perpetuating Life Internal fertilization – Internal development
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A. Evolution – theory that all species evolved from a pre-existing species; natural selection is the process by which evolution occurs; traits are selected for or against, this results in some characteristics being passed on to future generations and some are not pre-existing species; natural selection is the process by which evolution occurs; traits are selected for or against, this results in some characteristics being passed on to future generations and some are not B. Classifying Living Things – phylogeny is the evolutionary history of a species 1. binomial nomenclature – a two named system developed by Linnaeus 2. What do scientists look at when classifying? - comparative anatomy - comparative biochemistry (DNA/RNA) - Embryology - Cytology - Fossil record 3. Taxonomic Levels – See Table 4.2 3. Taxonomic Levels – See Table 4.2 V. Diversity of Life in the Sea
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Comparative Anatomy Comparative Biochemistry
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V. Diversity of Life in the Sea Comparing Fossils Comparative Embryology
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V. Diversity of Life in the Sea
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V. Diversity of Life
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V. Diversity of Life in the Sea
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