Cell DivisionCell Division

MitosisMitosis– GrowthGrowth and and RepairRepair– SomaticSomatic (body) cells (body) cells– Daughter cells:Daughter cells:

TwoTwo produced produced Diploid (2n)Diploid (2n) IdenticalIdentical to the parent to the parent

Cell DivisionCell Division

Interphase Prophase

Metaphase Anaphase Telophase

Steps of MitosisSteps of Mitosis– ProphaseProphase

Chromatin coiled to form discrete chromosomesChromatin coiled to form discrete chromosomes Nucleoli disappearNucleoli disappear Form mitotic spindle, lengthen microtubulesForm mitotic spindle, lengthen microtubules Nuclear membrane breaks downNuclear membrane breaks down Microtubules attach to chromosomes Microtubules attach to chromosomes

Steps of MitosisSteps of Mitosis

– MetaphaseMetaphase Chromosomes line up at Chromosomes line up at middlemiddle of cell of cell

Steps of MitosisSteps of Mitosis

– AnaphaseAnaphase Microtubules shortenMicrotubules shorten Chromatids Chromatids separateseparate, are pulled toward opposite , are pulled toward opposite

sides of the cellsides of the cell

Steps of MitosisSteps of MitosisTelophaseTelophase Daughter nuclei form at either sideDaughter nuclei form at either side Chromatin becomes less tightly coiledChromatin becomes less tightly coiled Cytokinesis (division of cytoplasm) occurs during Cytokinesis (division of cytoplasm) occurs during

telophase.telophase.

MeiosisMeiosis

SexualSexual reproduction (Why is meiosis reproduction (Why is meiosis required for sexual reproduction?)required for sexual reproduction?)

Form Form gametesgametes (sperm and egg) (sperm and egg) Daughter cellsDaughter cells

– FourFour produced (two nuclear divisions) produced (two nuclear divisions)– HaploidHaploid (n, cuts the number of chromosomes in (n, cuts the number of chromosomes in

halfhalf))– Different from parent and unique from each Different from parent and unique from each

otherother

MeiosisMeiosis

Steps:Steps:– Prophase IProphase I– Metaphase IMetaphase I– Anaphase IAnaphase I– Telophase ITelophase I– Prophase IIProphase II– Metaphase IIMetaphase II– Anaphase IIAnaphase II– Telophase IITelophase II

MeiosisMeiosis

Comparing Mitosis and Meiosis:Comparing Mitosis and Meiosis:

Comparing Mitosis and Meiosis:Comparing Mitosis and Meiosis:

Genetics/ DNAGenetics/ DNA

Heredity and Mendelian GeneticsHeredity and Mendelian Genetics– Genetics: The study of Genetics: The study of heredityheredity (the passing of (the passing of

traits from parents to offspring)traits from parents to offspring)

– Gregor Mendel: The father of genetics.Gregor Mendel: The father of genetics.

– DNA: Consists of many DNA: Consists of many genesgenes– Gene: Stretch of DNA that codes Gene: Stretch of DNA that codes

for a given for a given traittrait..– Allele: Alternate Allele: Alternate versionversion of a gene of a gene

CHROMOSOMESCHROMOSOMES: : Located in nucleus;Located in nucleus;

Split and produce new cells; contain genesSplit and produce new cells; contain genes

Body Cells:Body Cells:– Make up most of the Make up most of the

body’s tissues and organsbody’s tissues and organs

– 2 of each chromosome for 2 of each chromosome for a total of 46a total of 46

Sex Cells:Sex Cells:– Sperm cell (male) or Sperm cell (male) or

egg cell (female)egg cell (female)– Only 1 kind of each Only 1 kind of each

chromosome; chromosome; – Half # chromosomes in Half # chromosomes in

body cells (23)body cells (23)

Genetics/ DNAGenetics/ DNA

Dominant and Recessive TraitsDominant and Recessive Traits Dominant AlleleDominant Allele

– Gene that is fully expressed.Gene that is fully expressed.– MasksMasks/ “speaks louder than” a recessive allele./ “speaks louder than” a recessive allele.

Recessive AlleleRecessive Allele– Masked/not expressed if dominant allele is Masked/not expressed if dominant allele is

present.present.– Only expressed if dominant allele is Only expressed if dominant allele is absentabsent..

Genetics/ DNAGenetics/ DNA

GenotypeGenotype The The geneticgenetic makeup of an organism makeup of an organism

– Homozygous: having two of the Homozygous: having two of the samesame allele allele BB bbBB bb

– Heterozygous: having two Heterozygous: having two differentdifferent alleles. Bb alleles. Bb– Homozygous Dominant: having two Homozygous Dominant: having two dominantdominant

alleles BBalleles BB– Homozygous Recessive: having two Homozygous Recessive: having two recessiverecessive

alleles bballeles bb– Heterozygous: having one of each allele BbHeterozygous: having one of each allele Bb

Genetics/ DNAGenetics/ DNA

PhenotypePhenotype The The phphysical and ysical and phphysiological traits of an ysiological traits of an

organismorganism How the genes are How the genes are expressedexpressed What you would see in a What you would see in a phphotographotograph

ExampleExample: :

In peas, Y is a dominant allele that instructs In peas, Y is a dominant allele that instructs for yellow seeds; y is a recessive allele that for yellow seeds; y is a recessive allele that produces green seeds. Given the following produces green seeds. Given the following genotypes, fill in the term that best genotypes, fill in the term that best describes each, and then indicate what the describes each, and then indicate what the phenotype of the organism will be.phenotype of the organism will be.

DNA/ GeneticsDNA/ Genetics A Punnett Square can be used to predict the A Punnett Square can be used to predict the

genotypes and phenotypes of the offspring genotypes and phenotypes of the offspring produced by a given genetic cross.produced by a given genetic cross.

GenerationsGenerations– Parental (P): The organisms involved in the Parental (P): The organisms involved in the initialinitial cross cross– First Filial (F1): The offspring of the First Filial (F1): The offspring of the ParentalParental

GenerationGeneration– Second Filial (F2): The offspring of the Second Filial (F2): The offspring of the

First First FilialFilial Generation Generation

Example:Example: A chicken and a rooster mate. The chicken has A chicken and a rooster mate. The chicken has

white feathers and the rooster has brown feathers. white feathers and the rooster has brown feathers. Brown is dominant, and white is recessive. Brown is dominant, and white is recessive. Assuming the rooster is heterozygous, predict the Assuming the rooster is heterozygous, predict the frequency of each genotype and phenotype in frequency of each genotype and phenotype in their offspring.their offspring.

What is the cellular process that determines which alleles an offspring will receive from their parents? Meiosis

PracticePractice:: 1. A plant that is homozygous dominant for 1. A plant that is homozygous dominant for

height is crossed with a plant that is height is crossed with a plant that is homozygous recessive. (T = tall; t = short). homozygous recessive. (T = tall; t = short). Use a Punnett Square to predict the Use a Punnett Square to predict the genotypic and phenotypic ratios of the F1 genotypic and phenotypic ratios of the F1 generation.generation.

Practice:Practice:

2. Using question number 1, what would be 2. Using question number 1, what would be the genotypic and phenotypic ratios of a the genotypic and phenotypic ratios of a cross of two F1 individuals?cross of two F1 individuals?

DNA/ GeneticsDNA/ Genetics

Determining SexDetermining Sex

Human male: Human male: XYXY Human female: Human female: XXXX

Which parent Which parent determines the determines the

sex of a human sex of a human offspring? offspring? FatherFather

What is the probability What is the probability of having a boy? of having a boy? A girl? A girl? 50%/50%50%/50%

DNA/ GeneticsDNA/ Genetics

Sex linked traitsSex linked traits

Carried on the X Carried on the X chromosomechromosome

Example: hemophilia, Example: hemophilia, color blindness.color blindness.

Disorders occur more Disorders occur more often in males than often in males than females. Why? females. Why?

Males have one X Males have one X chromosome, so if chromosome, so if one is defective, they one is defective, they do not have a backup do not have a backup copy as do females.copy as do females.

DNA/ GeneticsDNA/ Genetics

MutationMutation A change in the base sequence of DNA.A change in the base sequence of DNA. A change in DNA can lead to a change in the A change in DNA can lead to a change in the

protein coded for by that gene.protein coded for by that gene. A change in the protein structure can lead to A change in the protein structure can lead to

certain disorders, for example, sickle cell certain disorders, for example, sickle cell anemia.anemia.

The 6 KingdomsThe 6 Kingdoms

Bacteria and ArchaeaBacteria and Archaea SingleSingle Celled, prokaryote Celled, prokaryote Cell wallCell wall Live in damp places or in waterLive in damp places or in water Asexual reproduction—binary fissionAsexual reproduction—binary fission Decomposers Decomposers (breaks down organic material)(breaks down organic material) Nitrogen fixation (rhizobium)Nitrogen fixation (rhizobium) Parasites (tuberculosis, cholera, strep-throat)Parasites (tuberculosis, cholera, strep-throat) Symbiotic relationships (humans)Symbiotic relationships (humans)

The 6 KingdomsThe 6 KingdomsComplete the chart comparing bacteria and viruses:

The 6 KingdomsThe 6 Kingdoms

ProtistaProtista Eukaryotes Eukaryotes (has a (has a

nucleus)nucleus) Single CelledSingle Celled

– EuglenaEuglena– DiatomsDiatoms– DinoflagellatesDinoflagellates– CiliatesCiliates– FlagellatesFlagellates– Sacrodina (amoeba)Sacrodina (amoeba)– Sporozoa (malaria)Sporozoa (malaria)

Multi-celledMulti-celled– Kelp Kelp – SeaweedSeaweed

The 6 KingdomsThe 6 Kingdoms

PlantsPlants Multicellular, eukaryoticMulticellular, eukaryotic Examples:Examples:

The 6 KingdomsThe 6 Kingdoms

AnimalsAnimals

Multicelled, eukaryoticMulticelled, eukaryotic Examples:Examples:

The 6 KingdomsThe 6 Kingdoms

FungiFungi Multicelled or single celled; Multicelled or single celled;

eukaryoticeukaryotic

Examples:Examples:

The 6 KingdomsThe 6 Kingdoms

PlantsPlants Photosynthetic AutotrophsPhotosynthetic Autotrophs How are plant cells How are plant cells

different from animal different from animal cells? cells?

Plant cells have a cell Plant cells have a cell wall and vacuole; wall and vacuole; Plant cells do not Plant cells do not have centrioles and have centrioles and lysosomes.lysosomes.

The 6 KingdomsThe 6 Kingdoms Major parts of a plant:Major parts of a plant:

– RootsRoots absorb water and nutrients from the absorb water and nutrients from the soilsoil.. Store excess sugars (in the form of Store excess sugars (in the form of starchstarch))

– StemStem connects roots to the rest of the plantconnects roots to the rest of the plant

– LeavesLeaves site of site of photosynthesisphotosynthesis

The 6 KingdomsThe 6 Kingdoms

PlantsPlants Transport in a plantTransport in a plant

– Xylem: transports water and nutrients Xylem: transports water and nutrients from the roots to the rest of the plantfrom the roots to the rest of the plant

– Phloem: transports products of photosynthesis Phloem: transports products of photosynthesis to the rest of the plant.to the rest of the plant.

What environmental factors might affect a What environmental factors might affect a plant? plant? – Water supply, light, pH, acid rain, pollutantsWater supply, light, pH, acid rain, pollutants

EcologyEcology

BiomeBiome A major biological community that occurs over a A major biological community that occurs over a

largelarge areaarea of land. of land. Determined primarily by precipitationDetermined primarily by precipitation Affected by elevation, latitude, soil type, Affected by elevation, latitude, soil type,

geographical features.geographical features.

Terrestrial BiomesTerrestrial Biomes

Terrestrial BiomesTerrestrial BiomesTropical Rain ForestTropical Rain Forest Rain: 200-450 cm (80-180 in) per year Rain: 200-450 cm (80-180 in) per year

(A (A lotlot of rain) of rain) Rich in number of species Rich in number of species

(many different types of organisms)(many different types of organisms) Central America, South America, Africa, AsiaCentral America, South America, Africa, Asia Examples of Animals and Plants:Examples of Animals and Plants:

tree frog, monkeys, birds, tree frog, monkeys, birds, green canopygreen canopy

Terrestrial BiomesTerrestrial Biomes

DesertDesert Rain: fewer than 25 Rain: fewer than 25

cm (10 in) per year cm (10 in) per year (Very little rain) (Very little rain)

Sparse vegetationSparse vegetation May be warm or May be warm or

coldcold

Examples of Animals Examples of Animals and Plants: Cactus, and Plants: Cactus, snakes, lizards, snakes, lizards, nocturnal animalsnocturnal animals

Terrestrial BiomesTerrestrial Biomes

SavannaSavanna Rain: 90-150 cm (35-Rain: 90-150 cm (35-

60 in) per year60 in) per year

Prevalent in Africa.Prevalent in Africa. Dry grasslandDry grassland

Widely spaced trees; Widely spaced trees; animals active during animals active during rainy seasonrainy season

Examples of Animals Examples of Animals and Plants: giraffes, and Plants: giraffes, zebras, grasseszebras, grasses

Terrestrial BiomesTerrestrial Biomes

Temperate Deciduous Temperate Deciduous ForestForest

Rain: 75-250 cm Rain: 75-250 cm (30-100 in) (30-100 in)

Mild Climate, plentiful Mild Climate, plentiful rainrain

Deciduous trees shed Deciduous trees shed leaves in fallleaves in fall

Warm summer, cold winterWarm summer, cold winter Mammals hibernate in Mammals hibernate in

winter, birds migratewinter, birds migrate Eastern US, Southeastern Eastern US, Southeastern

Canada, Europe, AsiaCanada, Europe, Asia Examples of Animals and Examples of Animals and

Plants: Bears, Deer, Oak Plants: Bears, Deer, Oak TreesTrees

Terrestrial BiomesTerrestrial Biomes

Temperate GrasslandsTemperate Grasslands Halfway between Halfway between

equator and polesequator and poles

Interior of North Interior of North America, Eurasia, America, Eurasia, South AmericaSouth America

Fertile soil, used for Fertile soil, used for agricultureagriculture

Examples of Animals Examples of Animals and Plants: Grazing and Plants: Grazing animals (Bison), animals (Bison), grasses, field micegrasses, field mice

Terrestrial BiomesTerrestrial BiomesConiferous ForestConiferous Forest Cone bearing trees: pine, spruce, fir, hemlockCone bearing trees: pine, spruce, fir, hemlock Pacific Northwest (temperate rain forests)Pacific Northwest (temperate rain forests) Northern Coniferous Forest (Taiga)Northern Coniferous Forest (Taiga)

– Cold and wetCold and wet– Winters long and cold; Winters long and cold;

precipitation in summerprecipitation in summer– Coniferous forests Coniferous forests

(spruce and fir)(spruce and fir)– Large mammals: Large mammals:

elk, moose, deer, wolves, elk, moose, deer, wolves, bears, lynx, wolverinesbears, lynx, wolverines

Terrestrial BiomesTerrestrial Biomes

TundraTundra Between taiga and polesBetween taiga and poles 20% of Earth’s surface20% of Earth’s surface Rain: less than 25 cm Rain: less than 25 cm (10 in)(10 in)

Permafrost 1m deep (3ft)Permafrost 1m deep (3ft) Examples of animals: Examples of animals:

foxes, lemmings, owls, cariboufoxes, lemmings, owls, caribou Alpine TundraAlpine Tundra Found at high latitudesFound at high latitudes High winds and cold temperaturesHigh winds and cold temperatures

Aquatic BiomesAquatic Biomes

Freshwater CommunitiesFreshwater Communities Standing bodies of waterStanding bodies of water

– lakes, pondslakes, ponds Moving bodies of waterMoving bodies of water

– streams, riversstreams, rivers WetlandsWetlands

– Swamp, marsh, bogSwamp, marsh, bog ~2% of Earth’s surface~2% of Earth’s surface Plants, fishes, arthropods, mollusks, Plants, fishes, arthropods, mollusks,

microscopic organismsmicroscopic organisms

Aquatic BiomesAquatic BiomesMarine Communities (salt water)Marine Communities (salt water) 75% Earth’s surface covered by ocean75% Earth’s surface covered by ocean Average depth 3km (1.9mi)Average depth 3km (1.9mi) Mostly dark, coldMostly dark, cold Photosynthetic organisms mostly towards Photosynthetic organisms mostly towards

surfacesurface Heterotrophic organisms throughoutHeterotrophic organisms throughout Fish, plankton Fish, plankton

(algae, diatoms, bacteria).(algae, diatoms, bacteria).

Flow of Energy Through an Flow of Energy Through an EcosystemEcosystem

In order to live, organisms must obtain In order to live, organisms must obtain energy and nutrientsenergy and nutrients– HeterotrophsHeterotrophs

Obtain energy and nutrients from the Obtain energy and nutrients from the foodfood they they eateat

– AutotrophsAutotrophs Obtain energy from the Obtain energy from the sunsun Obtain nutrients from the soil.Obtain nutrients from the soil.

Flow of Energy Through an Flow of Energy Through an EcosystemEcosystem

ProducerProducer– Uses energy from the sun and carbon from the Uses energy from the sun and carbon from the

environment to environment to makemake its its ownown food. food.– ““Bottom of the food chain”Bottom of the food chain”– Why are producers necessary in any Why are producers necessary in any

ecosystem? ecosystem? Make energy from the sun Make energy from the sun available/usable for heterotrophs.available/usable for heterotrophs.

Flow of Energy Through an EcosystemFlow of Energy Through an Ecosystem

ConsumerConsumer– Obtains energy through Obtains energy through eating other organismseating other organisms

Herbivore: eats only Herbivore: eats only plantsplants Carnivore: eats only Carnivore: eats only animalsanimals Omnivore: eats both Omnivore: eats both plantsplants and and animalsanimals

– Primary consumer: eats producersPrimary consumer: eats producers– Secondary consumer: Secondary consumer:

eats the consumers that eats the consumers that eat the producerseat the producers

Flow of Energy Through an EcosystemFlow of Energy Through an Ecosystem

ConsumerConsumer Means of obtaining nutritionMeans of obtaining nutrition

– PredationPredation Ecological interaction in which one organism Ecological interaction in which one organism

(predator) feeds on another living (predator) feeds on another living organism(prey).organism(prey).

Predator may or may not kill the prey.Predator may or may not kill the prey.– ScavengingScavenging

An animal ingests dead plants, animals, or both.An animal ingests dead plants, animals, or both. Vultures, termites, beetlesVultures, termites, beetles

Flow of Energy Through an EcosystemFlow of Energy Through an Ecosystem

ConsumerConsumer Means of obtaining nutritionMeans of obtaining nutrition

– Decomposer (Decomposer (SaprophytesSaprophytes)) Breakdown (absorb nutrients from) non-living Breakdown (absorb nutrients from) non-living

– Organic material—corpses, plants, waste of living Organic material—corpses, plants, waste of living organisms—and convert them to inorganic forms.organisms—and convert them to inorganic forms. Bacteria, fungiBacteria, fungi Why are decomposers Why are decomposers

necessary in any ecosystem? necessary in any ecosystem? Recycle nutrients.Recycle nutrients.

Flow of Energy Through an Flow of Energy Through an EcosystemEcosystem

Food ChainFood Chain LinearLinear pathway of energy transport through an pathway of energy transport through an

ecosystemecosystem algaealgaekrillkrillcodcodsealsealkiller whalekiller whalebacteriabacteria Producers always come first in the food chain.Producers always come first in the food chain. Decomposers always come last in the food chain; Decomposers always come last in the food chain;

they will break down dead organisms and allow they will break down dead organisms and allow nutrients to be recycled.nutrients to be recycled.

Arrows indicate the Arrows indicate the directiondirection in which in which energyenergy flows through the ecosystem. flows through the ecosystem.

Bacteria/Decomposers

Flow of Energy Through an Flow of Energy Through an EcosystemEcosystem

Food WebFood Web A A networknetwork of interconnected food chains in of interconnected food chains in

an ecosysteman ecosystem Producers are at the beginning.Producers are at the beginning. Decomposers are at the end.Decomposers are at the end. Arrows indicate the Arrows indicate the directiondirection in which in which

energy flows through the ecosystem. energy flows through the ecosystem.

PracticePractice::

1. Draw a food chain with at least five 1. Draw a food chain with at least five organisms. Label all organisms as being a organisms. Label all organisms as being a producer, a consumer, or a decomposer. producer, a consumer, or a decomposer. Make sure arrows are drawn to show how Make sure arrows are drawn to show how the energy is transferred.the energy is transferred.

Bacteria / Bacteria / decomposersdecomposers

SunSun

PracticePractice::

2. How does a food chain prove the Law of 2. How does a food chain prove the Law of Conservation of Matter and Energy?Conservation of Matter and Energy?

The energy is not disappearing but is being The energy is not disappearing but is being transferred from one organism to another.transferred from one organism to another.

SymbiosisSymbiosis

““LivingLiving TogetherTogether”” Ecological interaction in which two or more Ecological interaction in which two or more

species live together in a close, long-term species live together in a close, long-term association.association.

SymbiosisSymbiosis MutualismMutualism

– BothBoth partnerspartners benefitbenefit– Ants and aphidsAnts and aphids

Aphids supply sugars to ants; ants protect aphids Aphids supply sugars to ants; ants protect aphids from insect predatorsfrom insect predators

SymbiosisSymbiosis

CommensalismCommensalism– One species One species benefitsbenefits, the other is , the other is neitherneither

harmed nor helpedharmed nor helped– Birds and bisonBirds and bison– Birds feed on insects flushed out of grass by Birds feed on insects flushed out of grass by

grazing bisongrazing bison– Barnacles and whalesBarnacles and whales

SymbiosisSymbiosis

ParasitismParasitism– One species (the parasite) One species (the parasite) benefitsbenefits; the other ; the other

(the host) is (the host) is harmedharmed..– One organism feeds on and usually lives on or One organism feeds on and usually lives on or

in another.in another.– Bacterial infection of animalsBacterial infection of animals– Fungus infects treesFungus infects trees– MalariaMalaria

PracticePractice