BIOLOGY CLEP NOTES

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• 115 multiple choice questions

• 90 mins

• No penalty for guessing

• Scores are available immediately – need a 50 to pass

MOLECULAR & CELLULAR

(1.1) Chemical Composition of Organisms

(1.1.1) Reactions and Bonds

Matter and Elements

• Matter – anything that takes up space and has mass, made of elements (rocks, gasses, kittens)

• Elements – cannot be broken down into other substances (carbon, oxygen, hydrogen)

• Atoms – smallest unit of matter (neutrons, electrons (-), and protons (+))

• Elements

  • Compound – 2+ different elements combined in a fixed ratio

    • Salt (NaCl)

  • Molecule – 2+ same or different elements combined in a fixed ratio

    • Oxygen Gas

• Atoms

  • Electrons

    • Found orbiting in shells

    • Valence shell – outermost shell contains valence electrons

    • Only valence electrons interact with other atoms

  • Chemical Bonds – attractions that keep atoms close together

    • Covalent Bonds

      • Sharing of a pair of electrons

      • Strong bonds

      • Nonpolar – equal sharing

      • Polar – non equal sharing

    • Ionic Bonds

      • Anion steals an electron from the cation

      • Strong bonds

    • Hydrogen Bonds

      • Form poles of H and O in water molecules

      • Weak bond

  • Chemical Reactions

    • Make and break chemical bonds

    • Reactants – start reaction

    • Products – produced end of reactions

• Energy

  • 1^st law thermos – energy cannot be created or destroyed

  • 2^nd law thermodynamics – reactions tend to increase disorder

  • Endothermic – take energy

  • Exothermic – release energy (bombs)

(1.1.2) Properties of Water

- Only molecule that exists in all three states

- Solid is less dense than liquid (ice floats)

- Adhesion – sticks to other molecules well

- Cohesion – sticks to itself well

- Surface tension – difficult to break the surface

- Universal solvent – just about everything dissolves in it

- High specific heat – longer to increase temperature

- Evaporative cooling

Acids and Bases

• Acids – dissolve in water and increase hydrogen ion concentration in the solution (H+) (ex Hydrochloric acid)

• Bases – dissolve in water and decrease the H+ (ex Ammonia)

• pH scale – smaller # acidic and larger is more basic

• 7 is neutral

• Buffers can bring anything towards neutral. You can combine a strong of each to make a neutral.

(1.1.3) Organic Molecules

• Organic Molecule – any molecule containing carbon

• Monomer – the smallest block to form organic molecules

• Polymer – many monomers make up a polymer (ex whole molecule)

• Molecules

  • Carbohydrates

    • Made up of carbon, oxygen, and hydrogen

    • Monosaccharide – monomer (ex glucose)

    • Polysaccharide – polymer (ex starch)

  • Lipids

    • Hydrophobic in nature

    • Waxes – form water barriers

    • Fats – energy storage

    • Phospholipids – cell membranes

    • Steroids - hormones

  • Proteins

    • Amino acids – monomer

    • Polypeptide (protein) – polymer

    • Enzymes, defense (antibodies), muscle

  • Nucleic Acids

    • Nucleotide - monomer

      • Deoxyribonucleic acid (DNA)

      • Ribonucleic Acid (RNA)

      • Used for information storage

      • Nucleotide Makeup

        • 1 Nitrogen base – (joint by hydrogen bonds)

Adenine (A)

Thymine (T) – DNA only

Uracil (U) – RNA only

Cytosine (C)

Guanine (G)

• Pairs - A & T/U and C&G

  • 1 Sugar

Deoxyribose – DNA

Ribose - RNA

• 1 Phosphate group (backbone squiggle)

(1.1.4) Origin of Life

• When - 3.5 million years ago life started

• What – bacteria and similar organisms

• Where – deep sea vents, hot springs, tide pools

• Steps

  • (1) simple organic molecules

  • (2) some able to replicate

  • (3) cell division

  • (4) self metabolism – convert food into chemical energy

• Common ancestry among all living things

  • Same basic cell membranes

  • Same glycolysis (metabolism)

  • DNA is the same (base pairs)

  • Fossils

(1.2) Cells – smallest units of living things

(1.2.1) Structure and Function of Cell Organelles

• Cytoplasm (the goo)

  • Jelly like substance where organelles are suspended

• Cell membrane (wall)

  • Lipid layer surrounding the cell

• Nucleus (command center/brain)

  • Stores and protects most of DNA

  • Nucleous - Makes RNA and ribosomes

• Ribosomes (protein factory)

  • Use DNA instructions to create proteins

  • Made up of RNA and proteins

• Endoplasmic Reticulum (coral reef)

  • Makes lipids

  • Detox

  • Makes secretory proteins

• Golgi Apparatus (Shipping center for ER products)

  • Receiving

  • Sorting

  • Modifying

• Mitochondria & Chloroplasts

  • Mitochondria – site of cell respiration (converts food to energy)

    • Converts sugar to ATP

  • Chloroplasts – site of photosynthesis (converts sunlight to energy)

    • Found in plants

  • Both

    • Own DNA & Ribosomes

    • Double membrane

    • Somewhat independent

• Cytoskeleton (scaffolding for cells)

  • Cell shape

  • Muscle movement

  • Highways

  • Organization

  • Centrosomes – organizes some of cytoskeleton & cell division

  • Microtubules are the largest of the 3 types of fibers

  • Intermediate filaments are stable and durable

  • Microfilaments support cellular projections like villi

• Cell wall (plants, bacteria, prokaryotes, and fungi)

  • Rigid structural support

  • Components – cellulose, pectin, chitin

(1.2.2) Properties of Cell Membranes

• Membranes

  • Boundary between inside of cell and surroundings

  • Selectively permeable

  • Phospholipid bilayer with proteins, other lipids, hybrid molecules

  • Lipid and proteins can move from side to side

  • Hypotonic – this cell loses water

  • 

• Phospholipid bilayer – two layers

  • White outside part is the hydrophilic part that likes to interact with water

  • Yellow inner is hydrophobic which doesn’t like water

• Selective permeability

  • Passive transport – diffusion across the membrane with no energy. Sometimes needs a “doorway” protein to get through.

    • Diffusion – each molecule moves random from higher to lower concentration (no energy) (think perfume)

    • Osmosis – diffusion of water (higher to lower)

    • Facilitated Diffusion – diffusion with a doorway (protein that only allows certain proteins)

      • 

  • Active transport – requires energy and a doorway protein

    • Energy is required. Moves molecules against or with concentration gradient.

    • Bulk transport – large molecules cant pass through membrane

(1.2.3) Comparison of Prokaryotic and Eukaryotic Cells

• All living things are prokaryotic or eukaryotic

  • Prokaryotic

    • Bacteria or archaea

    • Most ancestral living things

    • They have a cell membrane and cytoplasm

    • Contrast - Do not have a nucleus or organelles

    • Unicellular

    • Some have a cell wall and/or locomotor structures

    • Most abundant on planet

    • Helpful and harmful (gut vs infections)

  • Eukaryotic

    • Animals, plants, fungi

    • Evolved from prokaryotes

    • They have a cell membrane and cytoplasm

    • Contrast – internal organelles like nucleus, mitochondria and DNA in the nucleus. Can be unicellular or multicellular

    • Some have cell walls and/or locomotor structures

    • Size is limited by the ratio of cell surface to cell volume

(1.3) Enzymes

(1.3.1) Enzyme-Substrate Complex

• Activation Energy – energy barrier that breaks existing bonds before creating new bonds. Rate of reaction depends on activation energy (higher = slower reaction)

• Enzymes – proteins that are the catalysts that lower the activation energy (EX lactase is the catalysts for the milk sugar lactose)

  • Some enzymes break substrates into smaller pieces while others join two substrates together into one molecule

• Substrate – the molecule an enzyme interacts with

• Active site – the location where the enzyme and substrate interact

(1.3.2) Roles of Coenzymes & (1.3.3) Inorganic Cofactors

• Some enzymes need help from other molecules (cofactor)

• Cofactors – non-protein helper molecules that are necessary to help some enzymes function

  • Inorganic – inorganic cofactors (usually metal irons)

    • Iron

    • Magnese

    • Zinc

  • Organic – coenzymes (commonly vitamins)

    • Bond to the active site and help form the enzyme substrate complex

    • Cosubstrates are detachable

    • Prosthetic groups are permanent

(1.3.4) Inhibition and Regulation

• Inhibitors – molecules that compete with substrates for the active site (A2 – antiplasmin)

  • Sit in the active site and block

  • Attache to enzyme outside of the active site and change shape of active site so it does not work

• Inhibition can also be due to the shape change of the enzyme or active site. This is caused by temperature, ph, etc.

• Denaturation – change in enzyme shape that makes it stop working

• Regulation – cell controls the action of its own enzymes

  • Product of the reaction inhibits the enzyme

    • Reaction slows as product increases

    • 

  • Regulaor molecule controls shape of enzyme active site

    • Causes enzyme to fit/not fit depending on what the cell needs

    • EX – oxygen for hemoglobin

QUIZ

• Neurotransmitters contained in the vesicles enter the synapse through – exocytosis

• An enzyme-substrate complex is composed of just an enzyme and a substrate

• Enzymes don’t function only within living cells.

• Enzymes can be used over and over again.

• Enzymes are highly specific with regard to the reactions they catalyze

• Some enzymes contain an essential nonprotein component (cofactors)

• Most enzymes are denatured by high temperatures

• Limited amount of enzyme present

• When a protein is heated the tertiary structure is most likely to be disrupted

(1.4) Energy Transformations

(1.4.1) Cellular Respiration

• Cells convert food (glucose) into the energy molecule ATP

  • ATP is used any time energy is needed in an organism

• 

• Aerobic (with Oxygen)

  • Glycolysis – glucose is split to make 2 molecules of pyruvate and 2 net ATP (pyruvate goes on)

  • Pyruvate Oxidation – pyruvate converted into Acetyl CoA

  • Citric Acid Cycle – Acetyl CoA is converted into different molecules (a little ATP and other molecules that are used in the electron transport chain)

  • Electron Transport Chain – creates about 32 molecules ATP

• Anaerobic (without Oxygen) – convert pyruvate to ATP

  • Produces very little ATP compared to aerobic

  • Lactic Acid Fermentation

    • Lactic acid is a byproduct

  • Alcoholic Fermentation

    • Ethanol is a byproduct

(1.4.2) Photosynthesis

• 

• Converts energy from the sun into glucose that is used in cellular respiration to form ATP

• 2 processes

  • Light reactions – harvest sunlight

    • Take place in the thylakoid (inside chloroplast)

    • Capture light and use it as an energy source

    • Produce ATP and other molecules for dark reactions

    • Produce O2 as a byproduct

  • Dark reactions

    • Take place in the stroma (like the cytoplasm)

    • Use ATP from light and CO2 from air to make molecules used in light reactions

    • Produce glucose used in cellular respirations

(1.5) Cell Division

(1.5.1) Structure of Chromosomes

• Chromatin – DNA form before replication

• Chromosome – DNA wound up (only right before mitosis)

  • DNA is wound around proteins called histones

  • Each group of histones is called a nucleosome

  • Sister chromatids – copies of chromosomes made before mitosis

  • Centromere – visible construction that holds the sisters together

• Homologous chromosomes – have identical copies of the same gene in the same place. About the same size and shape and pair up before mitosis.

  • Alleles – variation of the same gene found on homologous chromosomes (one allele is dark hair and another is blonde hair)

  • Ploidy (n) – denotes the number of copies of a gene/chromosome

    • Haploid – 1n

    • Diploid – 2n

  • Karyotype – picture of chromosomes (for humans 2n=46)

  • READING – karyotypes, chromosome folding, and ploidy

(1.5.2) Mitosis, Miosis, and Cytokinesis

• Cell cycle

  • Interphase – 90% of a cells life (DNA is copied)

    • G1

    • S

    • G2

  • Mitotic Phase

  • 

    • Mitosis– parent cell splits into 2 identical daughter cells

      • Prophase – chromosomes condense (messy chromatin into tightly condensed chromosomes)

      • Metaphase – chromosomes line up along the metaphase plate

      • Anaphase – chromosomes are pulled at their poles

      • Telophase – chromosomes decondense back into chromatin

    • Cytokinesis – parent cell splits into 2 identical daughter cells and both are 2n

  • Meiosis – forms 4 unique 1n cells (sperm and egg)

    • Meiosis 1

      • 

      • Same order and jobs as Mitosis, but there is one difference. Crossing over occurs during prophase I. Theis forms new combinations of genes that were not present in the parent cell.

      • Prophase

      • Metaphase

      • Anaphase

      • Telophase

    • Meiosis 2

      • 

      • Same as Meiosis I but chromosomes have been through crossing over

      • End product is four haploid cells instead of 2 that result from mitosis and meiosis.

(1.6) Chemical Nature of the Gene

(1.6.1) Watson-Crick Model of Nucleic Acids

• Before Watson and Crick

  • 1860s Fredrick Miescher – discovered phosphate rich chemicals in white blood cell nuclei. He was detecting phosphate groups in DNA

  • 1920s Frederick Griffith – discovered that some kind of molecule transformed pneumonia bacteria from harmless to lethal

  • 1940s Avery, MacLeod, McCarthy – DNA was what transformed from harmless to lethal

  • 1950s Chase and Hersey – DNA, not proteins, were the genetic material

  • 1950s Erwin Chargaff – A=T and C=G

  • 1950s Roslind Franklin – X ray showed that DNA had helical structure

• Watson and Crick

  • James Watson and Francis Crick (1950)s – Published research in 1953

  • Found that the A-T bond was the same length as the C-G bond which was the reason for the double helix

(1.6.2) DNA Replication

• The Blueprint

  • DNA = blueprint for everything cells make and do

  • Before mitosis a cell must copy the daughter cells and DNA replication is making this copy

• Each Strand a Template

  • Each DNA strand is a template for a new strand because of the pairs

• Process

  • (1) The enzyme helicase breaks bond between nucleotides on the DNA strand. This unwinds the double helix. (Think that the helicase unzips)

  • (2) DNA polymerase reads the nucleotide pattern on the template strand

  • (3) Polymerase builds a new strand by matching the nucleotides to the template strand

  • (4) End product – two identical double helices are formed

(1.6.3) Mutations

• Mutations

  • Source of new genes (can be bad or good)

  • Genetic disorder if bad (EX sickle cell disease)

• Causes

  • Accidents during replication

  • Carcinogens (EX radiation)

• Types

  • Substitutions – wrong nucleotide is used

  • Frameshifts – extra or missing nucleotide

(1.6.4) Control of Protein Synthesis

• Gene

  • Segment of DNA that is the blueprint for specific protein

  • Control protein synthesis

• Stages of Protein Synthesis

  • Transcription

    • Gene is copied from DNA to RNA (U instead of T)

    • mRNA (messenger RNA) takes message to cytoplasm for translation

  • Translation

    • Sets of 3 nucleotides on the mRNA form codons

    • Codons are complimentary to anticodons that are found on the tRNA (transfer RNA)

    • tRNA carries amino acids (building blocks of proteins) from cytoplasm to ribosomes

    • Ribosomes match the anticodons to the codons and the amino acids are joined to form proteins

    • 

(1.6.5) Structural and Regulatory Genes

• Types of Proteins

  • Structural – genes code for proteins to create

    • Organs

    • Cell walls

    • Cytoskeleton

  • Regulatory – genes code for proteins to

    • Regulate growth

    • Control development

    • Start or stop transcription of certain genes

(1.6.6) Transformation

• Bacterial Genes

  • Prokaryotes – no nucleus

  • DNA can be changed more easily which is why we can become resistant to medicine

    • Transduction

      • A virus can put genes from one bacterium into another

    • Transformation

      • Bacteria can incorporate bite of DNA from the environment into their own genes

(1.6.7) Viruses

• Are they alive?

  • We don’t know

  • They have their own DNA/RNA, can only reproduce in host cells, and have no metabolism.

  • Instead of calling a virus a cell, we call it a particle or virion

• Structure

  • Smaller than the smallest bacteria

  • All have

    • Capsule

    • DNA or RNA

  • Some have

    • Enzymes

    • Attachment structures

• How do they work

  • (1) Virus invades a living host cell

  • (2) takes control of DNA replication (sometimes translation/transcription) and replicates itself.

  • Some viruses reprogram the immune system to stop working or attack itself

ORGANISMAL BIOLOGY

(2.1) Structure and Function of Plants

(2.1.1) Plant organs

• Shoots

  • Usually above ground

  • Sometimes has leaves flowers and fruits

  • Gather light and CO2 for phorosynthesis

• Leaves

  • Gather light

  • Modified or absent

• Flowers

  • Only present in angiosperms

  • Attract pollinators and release pollen

• Fruits

  • Mature reproductive organs

  • Contains seeds and sometimes flesh

• Roots

  • Absorb water and nutrients from soil

  • Below ground

  • Sometimes store energy and water

(2.1.2) Water and Mineral Acquisition

• Non-Vascular Plants

  • No transport tissues and small

• Vascular Plants

  • Transport vessels (for water, sugar and minerals)

  • Grasses, trees, cacti, herbs

• Vascular tissues

  • Specifically for transport

  • Xylem – transports water and minerals

• Transport

  • Water and minerals diffuse into the root cells

  • Cohesion – tension pulls water and minerals up through plant as water vapor is lost

(2.1.3) Food Translocation and Storage

• 

• Phloem

  • Food = sugars from photosynthesis

  • Phloem – food transport tissues that move sugars from leaves to rest of plant

• Sugar movement

  • Sugar builds up in the phloem

  • Water diffuses in from the Xylem – through osmosis

  • Water helps move the sugar turning it into sap. This moves throughout the plant

• Food storage

  • Some plants store carbohydrates as starch in stems or roots to use later when the plant has a hard time getting what it needs from the environment

  • Potatoes beets turnips

(2.2) Plan Reproduction and Development

(2.2.1) Alternation of Generations

• Alternation of phases

  • Plants life cycle alternated from haploid to diploid phases

    • This is dependent on age, time of the year, etc

  • Both phases undergo mitosis

  • Sporophyte is dominant in most plants

• Diploid and Haploid phases

  • Sporophyte – diploid phase (pine tree)

    • Produced spores via meiosis

    • Spores grow into gametophytes via mitosis

  • Gametophyte - haploid phase (pine cone)

    • Produces gametes via mitosis

    • These fuse together to form new diploid individuals (sporophytes)

• 

(2.2.2) Gamete Formation and Fertilization

• Plant Gametes

  • Male - sperm

  • Female - egg

  • Zygote – fused

  • Embryo – growing zygote (more than a few cells)

• Plant Sperm

  • From the male gametophyte

  • Produced in large numbers

  • Leave the plant to join the egg

  • Transmittal

    • Swimming – wet areas

    • Non Swimming – pollen grains

• Plant Eggs

  • From female gametophyte

  • Produced in small numbers but larger in size

  • Transmittal

    • Stay where they are

• Fertilization

  • Male and female fuse

  • Seed Plants

    • Sperm must grow through female plant tissue to reach the ovaries

  • Seedless Plants

    • Same as seed

(2.2.3) Growth and Development

• Plant Hormones

  • Transported in vascular system

  • Control growth and development

  • Several that interact with each other

• Auxins

  • Promote shoot elongation

  • Produced in the shoot tips

  • Transported from tip to base of shoot

• Cytokinin

  • Stimulate cytokinesis

  • Produced in growing tissues (roots, embryos, fruits)

• Gibberellins

  • Cell division and elongation

  • Fruit growth

  • Seed germination

  • Produced in young roots and leaves

• Abscisic Acid (ABA)

  • Slows growth

  • Acting in opposition to growth hormones

  • Ratio of ABA to growth hormones determines whether growth occurs

• Ethylene

  • Response to stress (drought, flood, injury)

  • Response to life cycle (ripening, and cell death)

(2.2.4) Tropisms and Photoperiodicity

• Tropism

  • Growth response in plants towards or away from stimulus

• Phototropism

  • Response to light

  • Positive - Plants grow towards light (shoots)

  • Negative - Plants grow away from light (roots)

• Gravitropism

  • Response to gravity

• Thigmotropism

  • Response to touch

  • Windy – grow short and thick in response to wind

  • Climbing – grow around (vines)

• Photoperiodicity

  • Response to relative lengths of night and day

  • Why plants grow at different times of the year

(2.3) Structure and Function in Animals

(2.3.1) Major Systems

• The Animal Body

  • Complex machine

  • Controlled by hormones

  • Affected by environment

• Digestive System

  • Processes ingested food and drink

• Respiratory System

  • Responsible for intake of essential gasses

• Circulatory System

  • Moves gasses, nutrients, and hormones

• Musculoskeletal System

  • Support

  • Stability

  • Movement

• Nervous System

  • Passes messages between brain and body

• Excretory system

  • Filters waste and excess water

• Immune/Lymphatic Systems

  • Defense against invaders

(2.3.2) Homeostasis

• Steady state – internal balance

  • Temperature

  • Ion concentration

  • Blood glucose/oxygen

• Homeostasis

  • Set point - maintains a variable (98.6)

  • Stimulus – fluctuation in variable (working out)

  • Sensor – detects stimuli and send signal to control center (nervous system) -> (brain)

  • Control center – generated output that riggers a physiological response (sweat)

  • Hormones – chemicals used as signals

  • Relies on negative feedback cycles

• Thermoregulation

  • Endothermy – internal temperature regulation through heat generation (mammals and birds)

  • Ectothermy – internal temperature regulated by external environment (reptiles and fish)

(2.3.3) Hormones in Homeostasis and Reproduction

• Endocrine System

  • Regulated body’s set points

  • Triggers important events (puberty and reproduction)

  • Facilitates cell to cell communication (glucose uptake or antihistamine release)

    • Reaction to dust mites or pollen

• Hormone

  • Affects growth, metabolism, development, and homeostasis.

  • Chemical secreted by an endocrine gland/ organ into the blood

• Endocrine Glad

  • A ductless gland or single cell that secretes a hormone

  • Hormone target the cells or organs that have receptors for it

  • EX. Eat, digest, glucose rises, pancreas secretes insulin into the blood, glucose is transported into cells and liver to store as glycogen, glucose levels drop, and the pancreas stops secreting insulin.

• Hormones as Signals

  • Released by brain

  • Work as signals in two ways

    • Diffuse into cell cytoplasm and join receptor protein (causes a response)

    • Join receptor protein in cell membranes (causes a response)

• Hormones in Reproduction

  • Develop gonads – release hormones

  • Develop sperm and eggs

  • Release eggs

  • Develop embryos

  • Contractions during labor

  • Lactation and Maternal behavior

(2.4) Animal Reproduction and Development

(2.4.1) Gamete Formation and Fertilization

• Reproduction (2 processes)

  • Gametogenesis

    • Making gametes

      • Sperm

      • Eggs

  • Fertilization

• Spermatogenesis – formation of sperm

  • Primary spermatocytes (2n) formed

  • Secondary spermatocytes from primary (via Meiosis 1)

  • Sperm cells (1n -haploid) formed from secondary spermatocytes (via Meiosis 2)

  • 

• Oogenesis – formation of eggs

  • Occurs in oogonia – cells in ovaries

  • Primary oocyte (2n) present in ovaries from birth

  • Secondary oocytes (1n) formed from primary (via Meiosis 1)

  • Egg cells and polar bodies (1n) formed from secondary oocytes (via Meiosis 2)

  • Polar bodies recycled

  • 

• Fertilization – sperm and egg join to form zygote

(2.4.2) Cleavage, Gastrulation, Germ Layer Formation, Differentiation of Organ Systems

• The Zygote

  • Fertilized egg

  • All sexually reproducing multicellular organism starts here

• Cleavage

  • Zygotes divides many times without changing size

  • End up with many cells

• Development Stages

  • Morula – solid ball of cells

  • Blastula – hollow sphere of cells

  • Gastrula – hollow sphere of cells with tube that forms into the digestive canal

• Germ Layers – layers of tissue in developing organism

  • Endoderm – inside, forms alimentary canal

  • Mesoderm – in middle, form muscles, bones, circulatory and reproductive systems

  • Ectoderm – outside, forms skin

(2.4.3) Analysis of Vertebrate Development

• Model Organisms

  • Used to learn about generalities in vertebrate development

• Zebra Fish

  • Embryos have been used to explore

    • Effects of inhibitors

    • Effects of alcohol

    • Stages of Development

• Frogs

  • Used to learn about

    • Blastula formation

    • Causes of two – headedness

    • Control of spinal formation

• Chicks

  • Used to learn

    • Formation of limbs

    • Signaling molecules during embryonic development

• Mice

  • Used to learn

    • Toe formation and separation

    • Cell fate determinants

• Fish in space

  • The medaka and Asian relative of the zebrafish is being used to study the effects of low gravity embryo development

(2.4.4) Extraembryonic Membranes of Vertebrates

• Membranes outside the embryo during development

• Chorion

  • Regulates water, gasses, nutrients, and waste

  • Directly in contact with the uterine lining

• Amnion

  • Fluid-filled sac around embryo

  • Cushioning and temperature regulation

• Allantois

  • Comes from developing digestive track, gas, nutrient exchange

  • Becomes umbilical chord (non egg layers) / waste storage (egg layers)

• Yolk Sac Membrane

  • Comes from developing digestive track and encloses yolk sac that stores nutrients

  • Becomes umbilical chord (non egg layers) / larger (egg layers)

(2.4.5) Formation and Function of the Mammalian Placenta

• Placenta Formation

  • Formed from outer cells of embryo and inner cells of uterus

  • Connection between mother and embryo

• Placenta

  • Function – transfer nutrients, water, wastes between mother and embryo

(2.4.6) Blood Circulation in the Human Embryo

• Human embryos develop own blood vessels

  • Embryo blood vessels are next to mothers and exchange via diffusion

    • From mother – nutrients, water, oxygen

    • To mother – carbon dioxide and waste

(2.5) Principles of Heredity

(2.5.1) Mendelian Inheritance

• Gregor Mendel

  • Inheritance – characteristics passed from one generation to another in the genes

  • Austian monk who studied the pea plant

  • First to quantify genetic tests

• Mendel terms

  • Allele – alternate form of a gene (2 allele for each gene R or r)

  • Homozygous – 2 copied of the same (RR or rr)

  • Heterozygous – 1 copy of each allele (Rr or rR)

  • Dominant Allele – always expressed when present (R,G,N)

  • Recessive Allele – masked when dominant allele is present (r,g,n)

  • Genotype – allele carried by an individual

  • Phenotype – appearance of an individual

  • Cross – sexual reproduction between different individuals

  • Character – feature like hair color or plant height

  • Trait – the genotype or phenotype of an individual for a given character (red hair)

(2.5.2) Chromosomal Basis of Inheritance

• Mendel’s Laws

  • Law of Independent Assortment – each possible combination of alleles is equally likely for each gamete

  • Law of Segregation – paired genes separate and randomly recombine in gamete so offspring have equally likelihood of inheriting either

• Probability

  • If independent assortment occurs, laws of probability predict genotypes

  • Parental Generation (P) – the parents of a cross between the two individuals

  • First Filial Generation (F1) – offspring of P

  • Second Filial Generation (F2) – offspring from cross between two F1

  • 

• Punnett Square

  • Method of predicting offspring using probability

(2.5.3) Linkage

• Non-Mendelian Genetics

  • Since Mendel we have discovered that his law of independent assortment isn’t always true.

  • Some genes only on sex chromosomes

  • Some genes always inherited together

• Sex Linkage

  • Sex Linkage Genes – those located on either sex chromosome

  • Y genes are usually harmless because they are so small

  • X linked genes are responsible for several human genetic conditions

    • Color blindness in men

    • Duchenne muscular dystrophy in men

    • Hemophilia

• Cat Coat Color

  • Tortoiseshell coat coloration is the result of X-linked genes

    • Orange and black are both on the X chromosome

    • Males (Xy) express on their one X chromosome

      • Only males with XXy can be tortoiseshell or calico

    • Female (XX) express both colors causing both colors

• Other Linkage

  • Linkage – autosomal genes (not part of the sex chromosome) can be inherited together during meiosis if they are close together (because they were never fully split)

  • The farther genes are on a chromosome from one another the less likely they are to he inherited together

(2.5.4) Polygenic Inheritance

• Polygenic Inheritance – two or more genes affect the same phenotypic character (human height and eye and skin color)

• Disease – commonly caused by PI

  • Diabetes

  • Heart disease

  • Hypertension

POPULATION BIOLOGY

(3.1) Principles of Ecology

(3.1.1) Energy Flow and Productivity in Ecosystems

• Energy Cycle – food chain

  • Flow of energy in an ecosystem

• Trophic level

  • Producers – make energy accessible to eco systems via photosynthesis

  • Consumers – eat producers or other consumers

• Trophic categories

  • Autotrophs – self feeders. Make food from sun

  • Heterotrophs – consumers, get food from eating other organisms

• Ecological roles

  • Herbivores – eat plants

  • Carnivores – eat animals

  • Omnivores – eat both

• Transfer of energy

  • Inefficient due to heat loss

  • Each level gets 10% of previous energy

(3.1.2) Biogeochemical Cycles

• Biogeochemical cycles

  • Bio – living things

  • Geo – sediments/rocks

  • Chemical – molecules

  • Cycles – circular movements

  • Circular movements of molecules through an ecosystem’s living and nonliving things

• The Water Cycle

• Ocean – source of water

  • Freshwater system – source of water

  • Precipitation – falls

  • Evaporation – return

  • Condensation – gas to liquid form

• The Carbon Cycles

• Major storage of carbon – atmosphere, soil (fossil carbon), ocean (takes carbona and returns it to atm)

  • Return to atm – water and human emissions (fossil fuels)

  • Travels – evaporation and diffusion, terrestrial photosynthesis, and respiration

• Nitrogen Cycle – 80% of gas in atmosphere

• Removed from atmosphere – sediment falls to ocean floor, fixation (by bacteria), fertilizers, terrestrial organisms, and marine food webs

  • Back to atmosphere – denitrification (by bacteria in the water)

  • Sources – atmosphere and ocean floor

• Phosphorus Cycle

• Majority of phosphorus is in rocks

(3.1.3) Population Growth and Regulation

• Population – one organism or species living together

• Limiting Biotic Factors

  • Dispersal

  • Competition

  • Predators

  • Lack of food

  • Parasites

• Limiting Abiotic Factors – not living

  • Climate

  • Landscape

  • Soil

  • Water salinity

  • Sunlight

• Density – individual per unit area

  • Density – dependent regulators

    • Competition

    • Predation

    • Disease

  • Density-independent regulators

    • Climate

    • Disturbance

    • Pollution

• Demography and Growth

  • Demography – set of vital statistics (birth and death rate)

  • Growth Rate – how fast a population gets smaller or larger (r=births-deaths)

(3.1.4) Community Structure, Growth, Regulation

• Competition

  • More than one species in a community attempt to use the same limited resource

  • Competitive Exclusion Principle – not two species can occupy the same niche indefinitely (one will die off )

  • Niche partitioning allows coexistence – cactus vs rooted plants

  • Symbiosis – close interaction between two species

    • Mutualism – both benefits

    • Commensalism – one benefits and one is neutral

    • Parasitism – one benefits and the other is harmed

  • Succession – process through which a community recovers from a disturbance

    • Primary – no soil (lava, glacial moraine)

    • Secondary – soil present (abandoned fields)

(3.1.5) Habitat

• Species physical location including all biotic and abiotic factors it needs to survice

  • Pond

  • Forest

  • River

  • Grassland

(3.1.6) Concept of Niche

• A species role in a community

  • Time of day/year the species is active

  • Parts of the habitat is uses

  • How large are the prey it eats

  • What temperature it can tolerate

  • Trophic level

(3.1.7) Island Biogeography

• Biogeography – study of the distribution of organisms in space, historically and currently

• Island biogeography

  • Dispersal – how do species reach an island

    • Flying

    • Blown by wind

    • Floating by water

  • Species diversity – number of species on an island

    • Immigration and extinction – as diversity increases, immigration rate decreases, and extinction rate increases

    • Area affects – diversity is highest on large islands

    • Distance effects – Diversity is highest on islands near a mainland

    • Age effects – Diversity is higher on a older island

(3.1.8) Evolutionary Ecology

• Interactions

  • Physical Environment

  • Other species

    • One way – one species affect the other but not vise versa

    • Reciprocal – when two species affect each other

      • Predators and prey

      • Parasite and hos

      • Competitors

(3.2) Principles of Evolution

(3.2.1) History of Evolutionary Concepts

• Evolution – genetic change in a population over time

• Lamarck – proposed that organism acquired traits throughout their lifetime and pass these on (proven false)

(3.2.2) Concepts of Natural Selection

• Darwinian Concept - Natural selection drives evolution

  • More offspring are produced than can survive

  • Variation in characteristics (siblings and diff hair)

  • Better competitors have more offspring

  • Frequency of characteristic increases if it is good

  • Population is the smallest unit that can evolve

• Modern Synthesis – Darwin theory is supported but we know more

  • Characteristics result from genes

  • Variation in characteristics are from alleles

  • Evolution can take thousands of years

(3.2.3) Adaptive Radiation

• Adaptation – inherited characteristics that provide survival / reproductive advantages

  • Speed

  • Camouflage

  • Armor

  • Hearing

• Species – population of interbreeding individuals who don’t interbreed with other populations.

• Resource partitioning – decreases competition with species by using more specialized niches

• Adaptive radiation – result of resource partitioning

  • Alleles that allow resources to be used differently

  • Over time many new species evolve as a result of new niches (niche partitioning – birds with different beaks)

(3.2.4) Major Features of Plant and Animal Evolution

• Plant Evolution

  • Endosymbiont Theory – plants evolved from heterotrophs to autotrophs

  • Early plants were asexual

  • Movement to land created water storage and gravitation (root systems for water storage and stronger cell walls)

  • Separate sexes allowed for greater genetic diversity

  • First land plants did not have seeds

  • Evolution of flowers allowed for animals for pollination and seed dispersal

• Animal Evolution

  • First animals were aquatic, unicellular, and soft bodied

  • Next multicellular and hard structures

  • Invertebrates were the first on the land (spiders and scorpions)

  • Fish were the first with backbones

  • Adaptations for conserving water and gravity (amphibians)

  • Explosions – rapid increase in the diversity of living things

    • Cambrian explosion – increase in multicellular organisms

      • Aquatic plants

      • Major animal phyla evolved

      • New niches (active hunting)

(3.2.5) Concepts of Homology and Analogy

• Homology – similar structures resulting from common ancestry, could have different functions (ex arms – person, bird, cat)

• Analogy – similar structures from a common function but different ancestry (ex wings)

(3.2.6) Convergence, Extinction, Balances Polymorphisms, Genetic Drift

• Convergence – unrelated species evolve similar characteristics due to similar environments

• Extinction – when a species disappears from the planet forever

  • Permian extinction – (250 mya) 96% of species lost

• Balanced Polymorphism – natural selection tends to keep number of forms stable when one is scare its fitness increases (if less females they are in higher demand their fitness goes up) (when one morph increases, the other decreases)

  • Polymorphism – genetic diversity within a species for a particular trait

• Genetic Drift – random change in allele frequency for particular trait in a single population (ex storm kills majority of squirrels in a population with a light coat color)

(3.2.7) Classification of Living Organisms

• Taxonomy – organizes living things into groups based on appearance, genetics, and evolutionary history

• Carolus Linnaeus invented binomial nomenclature using genus and species “Scientific name” Borrelia burgdorferi

• Taxa – level of classification for living things (Cats)

  • The Domain – Eularya (eukaryotes)

    • Archea / Eubacteria (Prokaryotic)

    • Eukaryota (Eukaryotic)

  • Kingdom – Animalia (heterotrophs)

  • Phylum – Chordata (backbones)

  • Class – Mammalia (milk)

  • Order – carnivora (meat)

  • Family – Felidae (hypercarnivore, claws)

  • Genus – Felis (small)

  • Species – Catus (domesticated)

  • Scientific name – Felis Catus

• Eukaryote Kingdoms

  • Animalia – animals

  • Plantae – plants

  • Monera – fungi

  • Protista – unicellular

• Animal Phyla

  • Porifera – sponges

  • Cnidaria – jellies

  • Platyhelminthes – flatworms

  • Nematoda – roundworms

  • Mollusca – clams, snails, squid

  • Annelida – earthworms

  • Arthropoda – crabs, insects, spiders

  • Echinodermata – starfish, sea urchins

  • Chordata – fish, mammals, birds, reptiles, amphibians

(3.2.8) Evolutionary History of Humans

• Order Primates

  • Prosimians – lemurs lorises

  • Recent – tarsiers, new world monkeys, old world monkeys, apes-gorilla, chimpanzee, orangutan, human

• Great Apes

  • Humans, gorilla, chimpanzee, bonobos, and orangutangs

  • Hominids 4.5 million years ago, larger brains and bipedal locomotion

• Hominid Fossils

  • (Lucy) Australopithecus afarensis – 4.5 mya, head smaller, long arms

  • Homo erectus – first from genus – 1.8 mya, head larger and similar facial features

  • First homo sapiens (Cro-Magnon Man) – 100,000 looked like us

• Location of oldest human fossils from Africa. Suggest we evolved in Africa 100,000 years ago migrated throughout Europe, Asia, and the Americas

(3.3) Principles of Behavior

(3.3.1) Stereotyped learned social behavior

• Stereotyped behaviors – instinctive and performed in the same way by all individuals of species

  • Taxis – directional

  • Kinesis – Speed change

  • Reflex

  • Fixed Action Pattern – more complex series of behaviors

    • Behavior that continues when stimulus is removed

      • Courtship

      • Feeding young

      • Circadian rhythms

• Learned behaviors – not instinctive, must been seen and practices, can be stopped mid behavior

  • Conditioning – dogs drool when they smell food, a bell was introduced during meal time and the dogs still drools when they smell food

  • Habituation – a baby cries in the middle of the night but nothing happens so they eventually stop crying

  • Imprinting – Attachment to another animal or object. A hatchling gets attached to a human because it is the first thing they see when they are born

(3.3.2) Societies (insects, birds, primates)

• Society – organization of individuals in a population where tasks are divided so groups can work together

• Insect Societies

  • Bees

    • only queen breeds

    • only workers are her daughters

    • different jobs depending on age

      • nursery

      • cleaner

      • queen care

      • guard

      • forager

• Primate Societies

  • Built around dominance

    • Get best access to mates, resources, and toys

    • Individuals compete for status when the young matures

(3.4) Social Biology

(3.4.1) Human population growth

• Grow by same means as other populations (growth = births – deaths)

• Life Span

  • Better nutrition

  • Infant neutrality

• Growth rate

  • Over 7 billion people in 2016

  • Doubling time decreased

  • Technology increased food production

• Demographic transition

  • (1) birth and death rates equal and population in equilibrium

  • (2) Societal development of medicine and food allow population to increase

  • (3) Agrarian lifestyles (many children) become less common and people are having less children

  • (4) Medical advancement decreases infant mortality and urban populations increase

  • (5) industrialized countries have lower birthrates due to contraceptives

  • (6) increased population strains the environment resources

(3.4.2) Human intervention in natural world

• Human Population Size Effects on the environment

  • Pollution

    • Due to the industrial revolution

    • Addition of foreign substances to air water and soil – fertilizer, carbon emission, trash

  • Habitat Loss

  • Overharvesting

  • Introduced species

  • Climate change

(3.4.3) Biomedical progress

• Nutrition

  • Decreased sickness due to malnutrition (scurvy, anemia, and goiter)

• Medical Advances

  • Development of antibiotics

  • Vaccines

  • Antiviral treatments

• Treatments

  • Improved management to illness

• Other advancement

  • Genetically modified organisms

  • Use bacteria to make human insulin, vaccines, and cancer treatments.

  • Stem cells for organ transplantation