Basics of BiologyBasics of Biology

Chapter 4Chapter 4

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Developing Developing Shark Shark EmbryoEmbryo

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Four essential ingredients of Four essential ingredients of lifelife• CarbohydratesCarbohydrates- sugars and starches, like - sugars and starches, like

glucose- good energy sourceglucose- good energy source• ProteinsProteins- Made up of chains of amino acids - Made up of chains of amino acids

(have nitrogen in them)(have nitrogen in them)• Enzymes- proteins that speed up chemical Enzymes- proteins that speed up chemical

reactions reactions in the bodyin the body• Hormones- chemical messengers in the Hormones- chemical messengers in the

bodybody

• LipidsLipids- fats and oils, store energy- repel - fats and oils, store energy- repel water which is useful for many marine water which is useful for many marine mammals and birdsmammals and birds

• Nucleic acids-Nucleic acids- DNA and RNA, store and DNA and RNA, store and transmit genetic information for proteinstransmit genetic information for proteins

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Simple molecules Simple molecules have low energy, have low energy, complex complex molecules store molecules store energy in their energy in their bondsbonds

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Biochemical reactionsBiochemical reactions

• Substances are constantly being Substances are constantly being synthesized (put together) and broken synthesized (put together) and broken down to store or release energy for living down to store or release energy for living thingsthings

• Photosynthesis- capturing the sun’s energy Photosynthesis- capturing the sun’s energy to produce simple sugarsto produce simple sugars

• uses COuses CO2,2, releases O releases O22

• Respiration- breaks down food (sugars) to Respiration- breaks down food (sugars) to release energyrelease energy

• uses Ouses O2, 2, releases COreleases CO22

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Algae are the main Algae are the main photosynthetic photosynthetic organisms in the organisms in the ocean- ocean-

Sometimes it isn’t Sometimes it isn’t green due to many green due to many types of types of photosynthetic photosynthetic pigmentspigments

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RespirationRespiration

• The sugars produced by photosynthesis The sugars produced by photosynthesis are broken down to release energy for the are broken down to release energy for the cells.cells.

• Aerobic respiration- releases the most, Aerobic respiration- releases the most, and needs oxygen.and needs oxygen.

• Anaerobic- does not release as much Anaerobic- does not release as much energy, no oxygen required.energy, no oxygen required.

• -organisms that live in sediments or -organisms that live in sediments or in the guts of fishes. in the guts of fishes.

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Which produce and which Which produce and which eat?eat?

• Autotrophs- can produce their own Autotrophs- can produce their own food, mostly algae and bacteria in food, mostly algae and bacteria in the oceanthe ocean

• Heterotrophs- cannot Heterotrophs- cannot photosynthesize, all the animals that photosynthesize, all the animals that eat other organismseat other organisms

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In photosynthesis, In photosynthesis, solar energy is solar energy is converted to converted to chemical energy.chemical energy.-only done by -only done by autotrophsautotrophs

In respiration, In respiration, chemical energy is chemical energy is released for the released for the organisms to use.organisms to use.-both autotrophs -both autotrophs and heterotrophsand heterotrophs

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Prokaryotes do not Prokaryotes do not have a nucleus- this have a nucleus- this one is called a one is called a cyanobacteria, it cyanobacteria, it can can photosynthesizephotosynthesize

- bacteria only!!!!!- bacteria only!!!!!

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Eukaryotic cellsEukaryotic cells

• Have a nucleus and organellesHave a nucleus and organelles• All the other kingdoms- plant, animal, All the other kingdoms- plant, animal,

fungi and protists (algae and some fungi and protists (algae and some animal- like plankton)animal- like plankton)

• Plant cells- have a cell wall and a Plant cells- have a cell wall and a large vacuole for storing waterlarge vacuole for storing water

• Animal cells- no cell walls, no large Animal cells- no cell walls, no large vacuole.vacuole.

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Typical animal cell- no cell Typical animal cell- no cell wall.wall.

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Typical plant cell- note the cell Typical plant cell- note the cell wall and the water filled wall and the water filled vacuolevacuole

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Levels Of Organization- least Levels Of Organization- least complex to most complexcomplex to most complex

• Cell- Smallest unit of life, simplest form Cell- Smallest unit of life, simplest form of life- made of organelles which are of life- made of organelles which are made of moleculesmade of molecules

• Tissue- cells that are specific for a Tissue- cells that are specific for a functionfunction

• Organ- tissue organized into structuresOrgan- tissue organized into structures

• Organ system- a group of organs that Organ system- a group of organs that work togetherwork together

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Levels Of Organization- least Levels Of Organization- least complex to most complexcomplex to most complex

• Individual- a single organismIndividual- a single organism

• Population- a group of the same Population- a group of the same species living in an areaspecies living in an area

• Community- several populations of Community- several populations of different species in the same habitatdifferent species in the same habitat

• Ecosystem- the community AND the Ecosystem- the community AND the physical environmentphysical environment

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A Sponge is a A Sponge is a simple animal simple animal at the cellular at the cellular level of level of organization. organization. (No specialized (No specialized tissues or tissues or organs)organs)

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A A populationpopulation of Mussels of Mussels on a shore on a shore in New in New Zealand.Zealand.

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A A community community of mussels, barnacles of mussels, barnacles and seaweedsand seaweeds

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Table 4.01Table 4.01

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Diffusion- movement of molecules Diffusion- movement of molecules from High to Low concentrationfrom High to Low concentration

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Osmosis- Diffusion of water Osmosis- Diffusion of water into and out of a cellinto and out of a cell

• This is a major physiological issue for This is a major physiological issue for marine organisms!!!!marine organisms!!!!

• Water will always flow towards where Water will always flow towards where there is more solute (salts)there is more solute (salts)

• Marine organisms have a variety of Marine organisms have a variety of adaptations to be able to balance adaptations to be able to balance water and salts in their bodies.water and salts in their bodies.

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A cell responding to changes in A cell responding to changes in salinitysalinity

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Osmosis (cont’d)Osmosis (cont’d)

• Osmoconformers- Conform to salinity. Their Osmoconformers- Conform to salinity. Their internal salt concentration varies with internal salt concentration varies with changes in salinitychanges in salinity

• Osmoregulators- have special mechanisms Osmoregulators- have special mechanisms for maintaining a constant water/salt for maintaining a constant water/salt balance.balance.

• Most marine fishes tend to lose water, so Most marine fishes tend to lose water, so they compensate for this by excreting very they compensate for this by excreting very little water in their urine.little water in their urine.

• They also must excrete excess salts, some They also must excrete excess salts, some salts are excreted through urine, more salts salts are excreted through urine, more salts are excreted through the gills.are excreted through the gills.

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Figure 4.14aFigure 4.14a

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This Sea Turtle has glands near This Sea Turtle has glands near the eyes that excrete salty the eyes that excrete salty “tears”.“tears”.

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TemperatureTemperature

• All animals are greatly affected by All animals are greatly affected by temperature.temperature.

• Temperature plays a major role in determining Temperature plays a major role in determining where certain organisms live in the ocean.where certain organisms live in the ocean.

• Ectotherms or Poikilotherms- cold- bloodedEctotherms or Poikilotherms- cold- blooded

• Endotherms or homeotherms- warm-blooded. Endotherms or homeotherms- warm-blooded. These animals expend a great amount of These animals expend a great amount of energy to maintain a stable internal energy to maintain a stable internal temperature.temperature.

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Figure 4.16Figure 4.16

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Modes of reproductionModes of reproduction

• Asexual reproductionAsexual reproduction

• no gametes (sperm and eggs) are no gametes (sperm and eggs) are used, offspring are genetically used, offspring are genetically identical to parent.identical to parent.

• Examples- budding, fission, Examples- budding, fission, vegetative reproduction.vegetative reproduction.

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Asexual Reproduction- fission- Asexual Reproduction- fission- the two new cells are clones.the two new cells are clones.

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Asexual reproduction- budding Asexual reproduction- budding and rhizomes (runners)and rhizomes (runners)

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Modes of Reproduction Modes of Reproduction (cont’d)(cont’d)• Sexual reproduction- combining genetic Sexual reproduction- combining genetic

material of two parents to produce material of two parents to produce unique offspring.unique offspring.

• Sperm and Eggs (gametes) required.Sperm and Eggs (gametes) required.

• Each gamete has half the number of Each gamete has half the number of chromosomes required (haploid)chromosomes required (haploid)

• Upon fertilization the new individual has Upon fertilization the new individual has the right # of Chromosomes (diploid).the right # of Chromosomes (diploid).

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Reproductive StrategiesReproductive Strategies

• Broadcast Spawning- organisms Broadcast Spawning- organisms produce millions of gametes, no produce millions of gametes, no further interaction with offspring.further interaction with offspring.

• Most marine species fertilize Most marine species fertilize externally.externally.

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Photos of a coral spawning and Photos of a coral spawning and a giant clam spawninga giant clam spawning

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Organizing Life’s DiversityOrganizing Life’s Diversity• Biologists reconstruct the history of life on Biologists reconstruct the history of life on

earth is based upon a unifying concept in earth is based upon a unifying concept in biology- Evolution by Natural Selection.biology- Evolution by Natural Selection.

• Natural Selection- individuals with certain Natural Selection- individuals with certain traits give them an advantage in a given traits give them an advantage in a given environment.environment.

• These individuals will be more successful These individuals will be more successful in reproducing- ‘favorable’ traits are in reproducing- ‘favorable’ traits are passed on to offspring.passed on to offspring.

• Evolution is simply the genetic change in Evolution is simply the genetic change in populations over MANY generations.populations over MANY generations.

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Organizing Life (cont’d)Organizing Life (cont’d)

• Biological species concept- Biological species concept- Populations of organisms that have Populations of organisms that have common characteristics, and can common characteristics, and can interbreed.interbreed.

• Naming - We scientifically name Naming - We scientifically name organisms with two names the genus organisms with two names the genus and species. Ex. and species. Ex. Homo sapien, Homo sapien,

Tursiops truncatusTursiops truncatus

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Phylogeny- reconstructing Phylogeny- reconstructing evolutionevolution

• We use a branched diagram to try We use a branched diagram to try and reconstruct the evolutionary past and reconstruct the evolutionary past of groups of organisms.of groups of organisms.

• These records are constantly being These records are constantly being revised as we learn more about the revised as we learn more about the fossil record.fossil record.

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Figure 4.23Figure 4.23

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Probable Phylogeny of the six Probable Phylogeny of the six kingdomskingdoms

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The Tree of LifeThe Tree of Life• All organisms are classified into the All organisms are classified into the

following categories:following categories:• DomainDomain EukaryaEukarya• Kingdom Kingdom AnimaliaAnimalia• Phylum Phylum ChordataChordata• ClassClass MammaliaMammalia• OrderOrder PrimatePrimate• Family Family HominidaeHominidae• Genus Genus HomoHomo• SpeciesSpecies Homo sapienHomo sapien

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