biology with modifications by barb eisel modifications by barb eisel & ... for all cells. lipids...

Biology PSSA Prep Mrs. Jeffers

“Biology is the only science in which multiplication is

the same thing as division.”

Designed by Jackie Jeffers

With modifications by Barb Eisel & Theresa Banas

I. Levels of Organization

Cellular Level:

!  Draw a unicellular and a multicellular organism

!  25. Which shows the correct sequence of organization in mlticellular organisms?

A.  cell, organ, tissue, organ system B.  Tissue, cell, organ, organ system C.  Cell, tissue, organ, organ system D.  Organ, organ system, tissue, cell

Levels of Structural Organization

Figure 1.1, step 1

Molecules Atoms

Chemical level Atoms combine to form molecules


Figure 1.1, step 2

Smooth muscle cell Molecules Atoms Cellular level

Cells are made up of molecules Chemical level

Atoms combine to form molecules


Figure 1.1, step 3

Smooth muscle cell Molecules Atoms

Smooth muscle tissue

Cellular level Cells are made up of molecules

Tissue level Tissues consist of similar types of cells



Figure 1.1, step 4




Tissues consist of similar types of cells

Organ Organs are made up of different types of tissues



Figure 1.1, step 5



Cardio- vascular system


Tissue level Tissues similar types of cells

Organ level Organs are made up of different types of tissues

Organ system level Organ systems consist of different organs that work together closely


!  Features of Life?

Figure 1.2a

Human Homeostasis: Organ System Overview

!  Integumentary (Skin) ¶ Forms the external body

covering ¶ Protects deeper tissue

from injury

¶ Helps regulate body temperature

Figure 1.2b

Organ System Overview

!  Skeletal ¶ Protects and supports

body organs ¶ Provides muscle

attachment for movement ¶ Site of blood cell

formation ¶ Stores minerals

Figure 1.2c


!  Muscular ¶ Produces movement ¶ Maintains posture ¶ Produces heat


!  Nervous ¶ Fast-acting control

system ¶ Responds to internal and

external change ¶ Activates muscles and

glands Figure 1.2d


!  Endocrine ¶ Secretes regulatory

hormones !  Growth !  Reproduction !  Metabolism

Figure 1.2e

Figure 1.2f


!  Cardiovascular ¶ Transports materials in body

via blood pumped by heart !  Oxygen !  Carbon dioxide !  Nutrients !  Wastes


!  Lymphatic ¶ Returns fluids to blood

vessels ¶ Cleanses the blood ¶ Involved in immunity

Figure 1.2g


!  Respiratory ¶ Keeps blood supplied with

oxygen ¶ Removes carbon dioxide

Figure 1.2h


!  Digestive ¶ Breaks down food ¶ Allows for nutrient

absorption into blood ¶ Eliminates indigestible

material

Figure 1.2i


!  Urinary ¶ Eliminates nitrogenous

wastes ¶ Maintains acid-base

balance ¶ Regulates water and

electrolytes Figure 1.2j

Interrelationships Among Body Systems

Figure 1.3

Homeostasis

!  Homeostasis—maintenance of a stable internal environment ¶ A dynamic state of

equilibrium !  Homeostasis is necessary

for normal body functioning and to sustain life

!  Homeostatic imbalance ¶ A disturbance in

homeostasis resulting in disease

Figure 1.4, step 1a

Variable (in homeostasis)

Figure 1.4, step 1b

Stimulus: Produces change in variable Variable

(in homeostasis)

Figure 1.4, step 2

Change detected by receptor

Stimulus: Produces change in variable

Receptor (sensor)


Figure 1.4, step 3



Input: Information sent along afferent pathway to

Receptor (sensor)


Control center

Figure 1.4, step 4




Receptor (sensor) Effector


Output: Information sent along efferent pathway to activate

Control center

Figure 1.4, step 5




Receptor (sensor) Effector


Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis

Output: Information sent along efferent pathway to activate

Control center

Maintaining Homeostasis

!  The body communicates through neural and hormonal control systems ¶ Receptor

!  Responds to changes in the environment (stimuli)

!  Sends information to control center

Maintaining Homeostasis

¶ Control center (nervous & endocrine systems) !  Determines set point !  Analyzes information !  Determines appropriate response

¶ Effector !  Provides a means for response to

the stimulus

Feedback Mechanisms

!  Negative feedback ¶ Shuts off the original

stimulus, or reduces its intensity

¶ Works like a household thermostat

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Biochemistry Covalent Bonds Share Electrons Most Common Bond in Organic Compounds

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9. Water is the universal solvent because it is polar with uneven sharing of electrons causing ends to be oppositely charged.

8. Non polar molecules do not have charges on the ends. Equal sharing of electrons. Do not dissolve in water.

Water Properties

!  Cohesion !  Adhesion/Capillarity !  High specific heat

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Carbohydrates !   Carbohydrates are

organic compounds made of carbon, hydrogen and oxygen.

!   They are the key source of energy for all cells.

Lipids ! Nonpolar molecule

that are not soluble or mostly insoluble in water.

!   Includes fats, phospholipids, steroids and waxes.

!   Important part of the structure and function of cell membranes.

!   Store energy

Proteins !   A protein is a large

molecule made by linking together smaller molecules called amino acids.

!   Almost all life processes of a cell involve proteins which make up the structure and regulate the function of living things.

Enzymes !   Speed up chemical reactions by lowering

the activation energy. !   Made of proteins !   Bind with molecules (substrate) at the

active site (Lock & key fit) !   Not part of chemical reactions. !   Can be inactivated by changes in pH or

temperature (active site changes shape)

II. Classification

Taxonomy

!  Species- ¶ a group of organisms

that share similar characteristics and can interbreed to produce fertile offspring

Hierarchy- Taxonomic Groups

Domain Kingdom Phylum (Division – used for plants) Class Order Family Genus Species

BROADEST TAXON

Domains:

!  3 Domains: Bacteria, Achaea, Eukarya ¶ Bacteria & Archaea –

(Prokaryotic cells)

¶ Eukarya- (Eukaryotic cells) protists, fungi, plantae, animalia

Cells

!  Draw a prokaryotic cell and a eukaryotic cell

Overview !   Cell membrane separates living cell from

nonliving surroundings !   Controls traffic in & out of the cell

¶ selectively permeable ¶ allows some substances to cross more easily

than others !  hydrophobic vs hydrophilic

!   Made of phospholipids, proteins & other macromolecules

More than lipids… !   In 1972, S.J. Singer & G. Nicolson proposed that

membrane proteins are inserted into the phospholipid bilayer

It’s like a fluid… It’s like a mosaic… It’s the Fluid Mosaic Model!

Membrane is a collage of proteins & other molecules embedded in the fluid matrix of the lipid bilayer

Extracellular fluid

Cholesterol

Cytoplasm

Glycolipid

Transmembrane proteins

Filaments of cytoskeleton

Peripheral protein

Glycoprotein

Phospholipids

Many Functions of Membrane Proteins Outside

Plasma membrane

Inside Transporter Cell surface

receptor Enzyme activity

Cell surface identity marker

Attachment to the cytoskeleton

Cell adhesion

2007-2008

Movement across the Cell Membrane

Diffusion !   Move from HIGH to LOW concentration

¶ “passive transport” ¶ no energy needed

diffusion osmosis

movement of water

Channels through cell membrane

!   Membrane becomes semi-permeable with protein channels ¶ specific channels allow specific material

across cell membrane

inside cell

outside cell

sugar aa H2O

salt NH3

11/27/12

FACILITATED DIFFUSION: The diffusion of material through a channel in the plasma membrane.

11/27/12

Characteristics of Active Transport: 1. Can move LARGE molecules across the plasma membrane. example: glucose 2. Can move against the diffusion gradient - LOW to HIGH concentration requiring energy. 3. Sodium Potassium Pump, Endocytosis, Exocytosis.

III. Photosynthesis & Respiration

Photosynthesis:

6CO2 + 6H2O (light energy) C6H12O6 + 6O2

•  Chloroplasts •  Chlorophyll •  Requires ATP

Respiration C6H12O6 + 6O2 6CO2 + 6H2O +

Energy (ATP) Three pathways: •  Glycolysis

•  (changes sugar to pyruvic Acid)

•  Krebs Cycle •  Electron Transport chain Both Plants & Animals carry out

respiration

Cellular Respiration Total Energy Production:

¶ Glycolysis – 2 ATP’s

¶ Krebs Cycle- 2 ATP’s

¶ Electron Transport- 32 ATP’s

Total ATP output: 36 ATP

!  What are the two forms of reproduction and how do they differ?

A. Asexual Reproduction

!  Single cell divides !  Produces 2 new cells !  Exact # of chromosomes ¶ Offspring identical to

parent

¶ Budding in fungi

¶ Binary Fission in Bacteria

B. Sexual Reproduction

!  Requires two specialized cells- “Gametes” ¶ Meiosis- production of

gametes

VI. Mitosis & Meiosis

Prokaryotic Cell Division

¶ Binary fission !  DNA copied !  Cell divides into two cells !  Daughter cell is exactly like

parental cell

Binary Fission

Eukaryotic Cellular Division

!  Cell Cycle ¶ Cell grows

¶ Chromosomes copied

¶ 2 Daughter cells formed

!  Phases of the Cell Cycle: !  1. Interphase- most of the cells lifecycle is spent in Interphase ¶ Three phases:

!  G1 !  S (synthesis) !  G2

!  G1 ¶ Cell increases in size

¶ Organelles double

¶ New cytoplasm forms

!  S (synthesis) phase: ¶ Chromosomes replicate

!  2 identical stands “sister chromatids” o Joined together at the centromere

!  G2 Phase: ¶ Second growth phase

¶ Cell is now ready for Mitosis

!  2. Mitosis- ¶ nucleus divides

¶ Production of Diploid Cells (full number of chromosomes !  46 – 46 !  10-10

!  Four stages: ¶ A. prophase

¶  B. Metaphase

¶ C. Anaphase

¶ D. Telophase The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

!  A. Prophase: ¶ Nucleus breaks down

¶ Spindle fibers attach to centromeres

¶ Centrioles move to opposite poles

!  B. Metaphase: ¶ Sister chromatids line up

along the equator of the cell

!  C. Anaphase ¶ Spindle fibers pull sister

chromatids apart

¶ Spindle fibers pull chromatids to opposite ends of the cell

!  D. Telophase ¶ Spindle fibers disappear

¶ Nuclear membranes form (2 nuclei)

!  Cytokinesis- division of cell cytoplasm ¶ New cell membrane

forms (plants: cell wall)

¶ Membrane pinches off

¶ Result is two new daughter cells

Meiosis

!  Production of Haploid Cells (½ # of chromosomes)

!  46 – 23 10- 5

!  Production of Gametes (sex cells) ¶ Male: Sperm

¶ Female: Ova !  Each have ½ # chromosomes

!  Comprised of two parts, two cellular divisions: ¶ Meiosis I

¶ Meiosis II

!  Results in 4 genetically different cells

!  1 Diploid cell 4 Haploid cells

Meiosis I

!  Four stages: ¶ Prophase I

¶ Metaphase I

¶ Anaphase I

¶ Telophase I / Cytokinesis I

!  Prophase I ¶ Synapsis occurs-

!  homologous chromosomes pair up (form tetrad)

¶ Crossing –over occurs !  Genetic material exchanged

!  Metaphase I ¶ Independent assortment

occurs !  Homologous pairs line up in

center

!  Anaphase I ¶ Spindle fibers separate

homologous chromosomes

!  Telophase I- ¶ Results in 2 Diploid cells

that are genetically different from one another

Meiosis I

Meiosis II

!  Four stages ¶ Prophase II

¶ Metaphase II

¶ Anaphase II

¶ Telophase II

*Identical to mitosis

Meiosis II

!  Results in four haploid cells ¶ Each with unique

chromosomes

Meiosis II

!  Remember: Meiosis occurs in the Sex Cells; Mitosis occurs in all other cells

IV. DNA Replication & Protein Synthesis

!  Two Types of Nucleic Acids: ¶ DNA- deoxyribonucleic

acid

¶ RNA- ribonucleic acid

Structure of DNA:

!  Draw a strand of DNA

Structure of DNA

¶ Three parts: !  Sugar !  Phosphate !  Nitrogen base- Adenine, Thymine,

Guanine & Cytosine

¶ Double helix !  Sugar & phosphate backbone !  Nitrogen bases make up the rungs

Ribonucleic Acid

!  RNA: ¶ Single stranded

¶ Sugar is ribose

¶ Contains Uracil (no thymine)

DNA Replication

¶ Occurs before cellular division- Why?

¶ Process:

!  DNA unzipped by enzyme helicase !  Complementary base pairing and

proofreading by DNA polymerase o A-T T-A o G-C C-G

DNA:

What would be the complimentary strand for: ACG TAA CGG TAA? TGC ATT GCC ATT

DNA Mutations

!  Missense mutation = Base substitutions that cause replacement of one or more amino acids. Can negatively effect protein function or can be undetectable (silent)

DNA Mutations

!  Nonsense mutations = base substitutions that delete an amino acid and terminate protein synthesis. Usually destroys the function of the protein.

DNA Mutations

!  Frame shift = insertion or deletion of one or two bases. Shifts reading frame of codons.

DNA Mutations

!  Translocation= part of one chromosome becomes attached to another.

!  Inversion = segment of DNA breaks off, then reinserts in reverse.

Protein Synthesis

!  Transcription & Translation ¶ Production of Proteins-

large organic molecules !  Building blocks of cells

¶ Amino Acids !  Building blocks of proteins

Transcription

!   Occurs in the Nucleus: ¶ Production of RNA

!  Instructions for making proteins

¶ DNA unzips

Transcription

¶ Complementary RNA nucleotides lay down !  A-U, T-A, C-G, G-C !  Arranged in sequences of 3-

“Codons” o Codes for amino acids o Process controlled by enzyme RNA

polymerase

U = Uracil

Messenger RNA

!  A strand of DNA has the following sequence:

TCT GAT AAG ATC What sequence of bases will make up the strand of mRNA?

AGA CUA UUC UAG

!  mRNA: AGA CUA UUC UAG What amino acids does this strand code for?

mRNA Codon - Amino Acid Table

Amino Acids:

!  A strand of mRNA has the following sequence:

AGA CUA UUC UAG What amino acids does this strand code for?

Arg, leu, phe, Stop!

Translation

!  Occurs in the cytoplasm !  “Translation” of the mRNA

!  From mRNA to Amino Acids

¶ Ribosomes !  rRNA – produces proteins !  tRNA- carries amino acids to build

proteins

¶ Peptide Chain !  Chain of amino acids !  Twists to form proteins

www.columbia.edu/.../c2005/lectures/lec14_08.pdf

Genes & traits

!  Gene- ¶ section of chromosome

that codes for a trait

!  Allele- ¶ An

Alternate

form of a

gene.

!  Homologous Chromosomes- ¶ similar in size, shape & genetic

material

!  Chromosome # varies among organisms ¶ Human- 46

¶ Cat – 32

¶ Dog – 78

¶ Mosquito- 6

¶ Corn - 20

Alleles

!  Dominant- ¶ expresses its trait over

all other traits

¶ Represented by a capital letter !  AA, BB, TT, etc.

!  Recessive- ¶ expresses its trait ONLY

in the absence of a dominant allele

¶ Represented by small letters !  aa, tt, bb, etc.

!  Homozygous- ¶ Receives two dominant

or two recessive alleles !  AA, BB, tt, rr

!  Heterozygous- ¶ Receives one dominant

and one recessive allele !  Aa, Bb, Tt

!  Genotype- ¶ The alleles that an

organism actually receives: !  TT, Tt, tt, AA, Aa, aa

!  Phenotype- ¶ The traits that an

organism exhibits: !  TT = Tall !  Tt = Tall !  tt- = short

Predicting Genotype & Phenotype

!  Punnett Square ¶  predicts the probability

of the offspring's genotype and phenotype !  Monohybrid cross- looking at one

trait !  Dihybrid cross- looking at two

traits

!  In pea plants, round (R) seeds are dominant over wrinkled (r) seeds. Use a Punnett Square to set up a cross between two parents that are heterozygous for round seeds. (monohybrid cross)

R r

R

r

Genotypes: ¼ = RR ½ = Rr ¼ = rr Phenotypes: ¾ = Round ¼ = Wrinkled

P1 Cross:

RR Rr

Rr rr

!  Using offspring from the F1 generation, cross a homozygous dominant with a homozygous recessive

R R

r

r

Genotypes: 4/4, 100% = Rr Phenotypes: 4/4, 100% = Round

F1 Cross:

Rr Rr

Rr Rr

!  Show a Dihybrid cross of two heterozygous individuals to examine pod color and seed color. Green pods (G) are dominant over yellow pods (g) and yellow seeds (Y) are dominant over green seeds (y)

GY Gy gY gy

GY GGYY GGYy GgYY GgYy

Gy GGYy Ggyy GgYy Ggyy

gY GgYY GgYy ggYY ggYy

gy GgYy Ggyy ggYy ggyy

Gg Yy Gg Yy X

VII. Patterns of Inheritance

GY Gy gY gy

GY GGYY GGYy GgYY GgYy

Gy GGYy Ggyy GgYy Ggyy

gY GgYY GgYy ggYY ggYy

gy GgYy Ggyy ggYy ggyy

Law of Independent Assortment

!   Notice that the gene for one trait does not affect whether the gene of

another trait is inherited.

!  The Law of Independent Assortment states that genes for traits found on different chromosomes separate independently when gametes are formed

Other Patterns of Inheritance

!  Incomplete dominance ¶ Trait is

between the phenotypes of its parents !  Cross a red flower

with a white flower, all offspring are pink

! Codominance ¶ Both alleles are

expressed !  Cross a red flower with a white

flower, offspring are both red & white

!  Multiple alleles ¶ Genes that have more

than two alleles for a trait !  Human blood type- A,B, & O

!  Polygenic traits ¶ Traits influenced by more than one

gene

¶ Genes may be located on different chromosomes or at different positions on the same chromosome

!  Skin, eye color, hair, etc.

Expression is influenced by environmental factors

Sex-Linked Traits

! Autosome- any chromosome that is not a sex chromosome

!  Sex chromosome- X & Y chromosmes ¶ Determine the sex of the

individual !  XX = female XY = male

!  Sex-Linked traits ¶ Traits located on the X

or Y chromosome

!  X-Linked traits ¶ Typically recessive

¶ Male with recessive X, will have the trait

Colorblindness

C

Problem: ! Hermansky-Pudlak syndrome,

Albinism, is a sex-linked recessive disease.

!  A heterozygous female marries a man that has the disease……

Albinism

X Y

X

X

a

A XAXa XAY

XaXa XaY a

Pedigree

!  Pedigree- ¶ a diagram that shows

how a trait is inherited over generations !  Used to track sex-linked traits !  Squares = males, Circles =

females

Genetic Variations in Populations

Mutations & Variation

!  Variation- ¶ differences in traits

among members of a population

Mutations & Variation

!  Fitness- ¶ The ability to pass

desirable traits onto offspring in order for the continuation of the species.

Natural Selection

Change in Species

!  Adaptations- ¶ any trait that improves an

organism’s chance for survival & reproduction

!  Natural Selection is a scientific theory that explains the process of evolution.

!  Based on Four Principles:

!  1. Variation exists within populations

!  2. Organisms compete for limited natural resources.

!  3. Organisms produce more offspring than can survive

!  4. Individuals with variations suitable for their habitat survive and reproduce.

!  Biodiversity- ¶ variety in the number of

different kinds of species living on Earth

!  Extinction- ¶ occurs when there are

no longer any members of a living species on Earth

!  Mass Extinction- ¶ occurs when huge

numbers of species die out in a fairly short period of time.

Variations affect the Genetic Makeup of a population

!  Natural Selection- ¶ only the most fit and

those most adapted to their environment will survive & reproduce

!  Stabilizing selection- eliminates those that have extreme traits

!  Directional Selection- individuals at one end of the frequency distribution are better adapted to the environment than those in the middle

!  Disruptive Selection- individuals at the extreme ends of the distribution are better adapted than those in the middle

Speciation !  Species-

¶ group that share similar characteristics that interbreed to produce fertile offspring

!  Population- ¶ all the members of a

species that live in the same area at the same time

!  Speciation- ¶ evolution of a new

species from an existing species. Ex: Finch Beaks !  Geographic isolation ! Parapatric speciation !  Behavioral isolation

!  Geographic Isolation- ¶ population is divided by a

physical barrier into two geographically isolated populations. !  Differences become so great, they

can no longer interbreed

! Parapatric speciation- ¶ neighboring populations

live in different environments !  Hot, Dry env. Vs cold, wet !  Two pop. become genetically

different

!  Behavioral isolation- ¶ differences in courtship

rituals or other types of behaviors !  Choose different mates !  Leads to genetically different

individuals

Evolution in species

!  Gradual evolution = slow, steady change in a population to adapt.

!  Punctuated = sporadic changes, with long periods where no evolution occurs. Fits fossil records

Evolution in related species

!  Convergent vs divergent

Question #1

!   Based on a picture of Finch beaks and Darwin’s observations, which of the following best explains the differences in beak shapes?

A.  The different finch species have migrated and separated to their own islands to minimize competition.

B.  At some point in the past, the small tree finch must have bred with the cactus finch to create the vegetarian finch species.

C.  Each species developed beaks that made it easier to obtain the food they most liked to eat.

D.  Through adaptation, the species of finches have developed beaks that are better suited to the different foods available on their island.

Evolutionary Relationships

!  Phylogeny: ¶ study of evolutionary

history of related species !  Phylogenic Tree

Fossil Evidence -

Comparative Anatomy

!  Examine similar structures: ¶ Homologous Structures

¶ Analogous Structures

¶ Vestigial Structures !  Ex: Rat appendix vs human

appendix

Indicate shared ancestry

Homologous structures: Similar structure, differ in function

Analogous Structures: Similar function, differ in structure

!  Examine embryology ¶ Embryo- early stage in

the development of an organism

!  Examine Chemical components ¶ Sequence of nucleotides

¶ Sequence of amino acids

Question #4 !   An unknown organism is discovered in an

African tropical rainforest. The scientist describes it as multicellular,(nucleus, cell membrane, no cell wall or chloroplasts). Into which of the following kingdoms is the scientist most likely to place this organism?

A.  Protista B.  Animalia C.  Fungi D.  Plantae

Question: !   Scientists compare a fossil bird wing to the

structures making up a human arm and a whale flipper. They observe that the number and arrangement of bones in the forelimbs of all three animals are very similar. What does this finding suggest about the three animals?

!   A. They do not share a common ancestor. !   B. They share a common ancestor. !   C. They are all capable of using their

forelimbs for flight. !   D. they are all invertebrates.

Technology & Genetic Variation

!  Selective Breeding- ¶ allowing only organisms

with specific traits to reproduce !  Ex: show dogs, race horses

!  Biotechnology- ¶ using organisms for

practical purposes !  Perform certain tasks’ *Recombinant bacteria produce medicines like insulin

Biotechnology- using organisms for practical purposes

!  Genetically modified organisms

Improved food crops and livestock


!  Gene therapy Replacing genes for diseases with healthy versions in the future


!  Genetic testing and counseling for genetic disorders

!  Stem cell therapy for treatments of diseases and injuries

DNA Fingerprinting

!  DNA is cut into segments by restriction enzymes

!  Segments are separated according to size by gel electrophoresis

!  Creates unique barcode or “fingerprint” pattern

!  http://highered.mcgraw-hill.com/sites/dl/free/0072835125/126997/animation40.html

!  Genetic Engineering- ¶ genes or pieces of DNA are

taken from one organism and transferred to another organism !  Recombinant DNA-when 2 pieces of

DNA from different organisms join together

!  Cloning- ¶ genetically identical

individuals are created from a single cell

biology with modifications by barb eisel modifications by barb eisel & ... for all cells. lipids...

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