By: Zack White

Table of Contents Chapter 10 Chapter 11 Chapter 14 Chapter 16 Chapter 15.3 and 17.1 Chapter 17.4 Chapter 19 Nervous System Notes

Chapter 10

Limits to Cell Growth

DNA Overload! Inefficient exchange of materials! Cell volume increases too rapidly! The solution: Cell Division Cells that do not divide throughout

life would not encounter the issues above. DNA determines cell decline and death!

What are Chromosomes? Strands of DNA Every organism has a specific number

of chromosomes. Before cell division occurs, DNA must

be copied so each new cell will have DNA.

Once copied, the two identical stands (or Chromatids) are held together by a Centromere

Cell Cycle Interphase – growth period of cell, longest

stage of cell life.1. G1 phase – growth2. S phase – DNA replication3. G2 phase – preparation for mitosis Cell Division – division of the cell into 21. Mitosis – division of the cytoplasm2. Cytokinesis – division of the cytoplasm

Mitosis Prophase – chromatin condenses, centrioles

separate to opposite sides of cell (animal cells only), spindle forms, nuclear membrane breaks down

Metaphase – Chromosomes line up in the middle

Anaphase – Sister chromatids separate Telophase – chromosomes gather at

opposite ends, new nuclear membranes form

Cytokinesis

Division of the cytoplasm In animal cells: cleavage of cell

membrane. In plat cells: a cell plate forms midway

between the divided nuclei.

Cancer

Uncontrolled cell division DNA or proteins damaged by

carcinogens or genetically inherited. Carcinogens: radiation, chemicals,

viral

Table of Contents

End of Chapter 10 Notes!!!!!!!!!!!!!!!!!!!!!!!!!

Chapter 11 Notes

Chromosome Number

Each organism inherits 1 set of chromosomes from “mom” and 1 set from “dad”. (ex. In humans…)

A homologous pair = 1 chromosome pair

A diploid cell = 2 whole sets A haploid cell = 1 set (ex: sex cells)

Meiosis Reduction division What is it!? Two stages: Meiosis I and Meiosis II Meiosis I: Important events that take place:a. Pairing of tetrads What is tetrad?b. Crossing over What happens?c. Reduction division Meiosis II: same process as mitosis (no real

interphase II thus no 2nd S-phase)

Gamete Formation

Males Produce 4 sperm from 1 cell Each are haploidFemale Produce haploid eggs Cell divisions are uneven Only one cell receives most of the

cytoplasm Other smaller cells are called polar bodies

End of Chapter 11 Notes

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Chapter 14 Notes

Human Chromosomes Karyotype: picture of chromosomes

that are arranged in 23 pairs. Autosomes are pairs #1-22. Sex chromosomes are pair #23-Males have one X and one Y (XY)-Females have two X’s (XX) Human chromosome number is

written as: 46XX for a female and 46XY for a male

Autosomal Genetic Disorders Recessive alleles – two recessive alleles

to show disorder Ex: PKU, cystic fibrosis, albinism Dominant alleles – only one dominant

allele needed to show disorder.Ex. Huntington’s disease, achondroplasia Codominant alleles – only one

codominant allele needed to show disorder.Ex. Sickle cell anemia

Sex-Linked Traits Location: Sex chromosomes, pair #23 Most sex chromosome disorders are found on the “X”

chromosome of pair #23 Males only need 1 allele for the trait. Females need 2 alleles for the trait. Colorblindness – lack of ability to distinguish certain

colors Hemophilia – lack of a clotting factor in blood. Duchenne Muscular Dystrophy – defective muscle

protein that causes progressive weakening and loss of skeletal muscle.

Chromosomal Mutations Meiosis goes wrong at Anaphase I. Homologous pairs don’t separate Called: Nondisjunction1. Down Syndrome – 57XX or 47XY2. Klinefelter’s Syndrome – 47XXY3. Turner’s Syndrome – 45XO4. Metafemale – 47XXX or 48XXXX5. Jacob Syndrome – 47XYY

~!End of Chapter 14 Notes!~

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Chapter 16 Notes

Gene Frequencies and Hardy-Weinberg

Gene frequencies can be high or low no matter if the allele is dominant or recessive.

Frequencies can change depending on the conditions that exist in the environment.

It is the changes in gene frequencies over time that results in evolution.

Hardy-Weinberg

In 1908 Hardy-Weinberg made a principle that provides a way to determine whether gene frequencies have changed in a population, and thus, whether evolution has occurred.

Hardy-Weinberg Principle

This principle will be maintained in nature only if all five of the following conditions are met:

1. Very large population2. Isolation from other populations3. No net mutations4. Random mating5. No natural selection

Hardy’s Equations

P + q = 1P = frequency of dominant alleleQ = frequency of recessive allele

P2 + 2pq + q2 = 1P2 = frequency or % homozygous dominant

genotype2pq = frequency or % heterozygous genotypeQ2 = frequency or % homozygous recessive

genotype

Evolution Definition: Change over time Occurs on populations, not individuals.(Individuals do note evolve, but are part of

populations which do.) Evolution is the genetic change occurring in

a population of organisms over time. Darwin’s Natural Selection is the

mechanism that runs evolutionary theory…

Evolution by Natural Selection

The Struggle for Existence (compete for food, mates, space, water, etc.)

Survival of the Fittest (strongest able to survive and reproduce)

Works upon the PHENOTYPES not the genotypes of any population.

Darwin’s Observations

In any population, there is variation with no two individuals being exactly alike.

Much of this variation between individuals is inheritable

What are the Sources of Variations?

Gene shuffling and crossing over from Meiosis.

Zygote production or fertilization Mutations

What is a Gene Pool?

All the alleles or genes for all the traits for a given population.

How common is a particular allele in a gene pool is its: GENE FREQUENCY

What is an adaptation?

Any trait that increases an animal’s chance for survival in a particular environment.

Those with the best adaptation for the environment are the FITTEST and will reproduce more.

Patterns for Natural Selection Single-Gene trait – only two alleles,

with two distinct phenotypes; show all-o-nothing pattern from natural selection.

Polygenic Traits – many allele possibilities with several phenotypes; show continuous variation just shifts in distribution

Ex: directional, stabilizing,

Artificial Selection

Humans slelect those traits they found most useful

Domesticated animalsDog breedsMilk production in cows Genetically engineered crops

What if natural selection does not play a role in gene frequency?

GENETIC DRIFT

Notes 16.3

In the process of evolution, natural Selection and genetic drift can lead to the ultimate differentiation…Speciation

What is a species?

A group of similar organisms that can breed and produce fertile offspring.

So, once members of two populations cannot interbreed and produce fertile offspring, they are considered 2 different species

They are reproductively isolatedHow could this happen!?!?!?!?

Some Isolating Mechanisms

Geographical – barriers such as rivers, mountains or bodies of water separate a population

Behavioral – different courtship rituals Temporal – reproduce at different

times of the year

Darwin’s Finches is an example of speciation

Finches on the islands resembled a mainland finch

More types of finches appeared on the islands where the available food was different (seeds, nuts, berries, insects)

Finches had different types of beaks adapted to their type of food gathering

Speciation of Darwin’s Finches Founders Arrive – few finches from the

island from the South American mainland reach island.

Separation of Populations – Geographic isolation by being on different islands

Changes in gene pools – by natural selection

Reproductive isolation – do not recognize behaviors or physical traits etc.

Continued evolution over many generations

End of Chapter 16 Notes!!!!

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What Evidence is there for Evolution?

Sections 15.3 and 17.1

Fossil Record The Fossil Record – incomplete record of life

on earth-sedimentary rock forms most fossils-proves life on earth has changed over time Relative Dating – estimating a fossil’s age

by comparing it with other fossils Radioactive Dating – calculation of sample’s

age based on the amount of radioactive isotope it contains.

Geographic distribution of species

Unrelated species share similarities because of similar adaptations to the environment.

Biochemical Similarities

All organisms use DNA or RNA; cell respiration process

Homologous Structures

Same embryonic origin but have different mature forms.

Vestigial organs are useless structures that many have been used by ancestors.

Embryology

Embryonic cell development patterns are the same in all vertebrates

Descent with modification

Species today look different from their ancestors because they have similar traits

Each living species has:-descended-with changes-from other species-over time

Common Descent

All living things were derived from common ancestors

Cladograms can help to show this

End of 15.3 and 17.1 Notes

Table of Contents

Evolution patterns

17.4

Macroevolution

Large-scale evolutionary patterns and processes that occur over long periods of time

Microevolution Small-scale changes in allele

frequencies over a few generations at or below the species level

A Driving Force of Evolution: Extinction

More than 99% of all species that had ever lived on earth are now extinct.

Usual reasons: competition, environmental changes

Mass extinctions account for large changes wiping out entire ecosystems

Leaving many open niches to be filled by those that survived.

Divergent Evolution

Many species developing from one. A.k.a. Adaptive Radiation Example: Darwin’s finches Evolving through natural selection Usually a slow process Disappearance of dinosaurs cleared

the way for adaptive radiation of mammals.

Convergent Evolution

Process where unrelated organisms come to resemble each other or have similar looking traits.

Environmental conditions are the same.

Convergent evolution may lead to the formation analogous structures

Coevolution

Two species evolve in response to changes in each other over time.

Formation of symbiotic relationships Advantages: less competition Disadvantages: too specific

End of 17.4 Notes!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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Chapter 19

Viruses and Bacteria

What is a virus?

Ultramicroscopic infectious agents that replicates itself only within cells of living hosts.

Many are pathogenic Composed of a piece of nucleic acid

wrapped in a thin coat of protein.

Virus Genetic Material

DNAfairly stable from radical mutationsEx: polio, small pox

RNA Mutations are commonRetrovirusesEx: influenza, HIV

Viral Reproduction TypesLytic Cycle Quick in process Takes over host cell Forces host to make more virus Uses host’s materials Destroys host cellLysogenic Slower process Prophage inserted into host’s DNA Hides in host’s DNA until activated Once activated, continues with lytic cycle

How fast can they replicate

A virulent virus may complete its lifecycle in 30 minutes, producing 200 new viruses.

Flu of 1918 killed people over 24 hours.

How can a viral infection be cured

There is no cure for a viral infection Vaccines must be taken before you

are infected Once infected, body must fight off the

infection Antiviral drugs are available to treat

only a few viral diseases

Prion

Protein infectious particles No genetic material Diseases: Mad Cow, scrapie and

Creutzfeldt-Jacob Nervous tissue with prions must be

ingested

Diseases

See Textbook Figure 19-5

What is a Prokaryote

An organism with no nucleus and unicellular.

ALL BACTERIA!!!!!!!!!!!!!!!!!!!!!!!!!

Classification

Movement Non-Motile Flagella Slime

Bacteria Shapes

Three basic – Bacillus (rod), coccus (sphere), and spirillum (spiral)

Gram Staining Technique

Cell Walls: thick or thin peptidoglycan walls. Gram staining is used to identify.

Metabolic Diversity

HeterotrophsChemoheterotrophPhotoheterotroph

AutotrophsPhotoautotrophsChemoautotrophs

Energy Release

Two ways: respiration and fermentation

Classified based on how they release energy from food:

Obligate aerobes Obligate anaerobes Facultative anaerobes

Growth and Reproduction

Binary Fission – simple mitosis Conjugation – Swapping genetic

material Endospore Formation – thick coat for

dormant times.

Bacterial Importance

Photosynthesis Decomposers – sewage treatment Nitrogen Fixers – fertilizer for plants Biological – vitamin K production,

fiber breakdown Genetic Engineering – production of

hormones for medical purposes

Disease

Pathogen – disease causing agent Cell and tissue destruction of infected

organism. Food consumption of bacteria

Releases toxins that poison the host and cause symptoms of disease.

Prevention and Control Vaccines – given to prevent illness Antibiotics – given after infection to kill

bacteria-Over usage problems-Conjugation Sterilization – exposure to high heat Disinfectants – chemical solutions Refrigeration Cooking Canning and Preservatives

Chapter 40 Notes

The Immune System

Immune System Function

To recognize, attack, destroy, and remember pathogens that invade our body.

Two types of defense systems

Nonspecific defense Specific defense

Nonspecific Defenses

Does not discriminate between any type of threat – Attacks all

Provided by physical or chemical barriers

1st Line of Defense Skin and Mucus membranes

(skin pH and stomach, saliva, tears, sticky mucus traps)

2nd line of defense: inflammatory response and fever

Blood vessels dilate from histamine release, phagocytes move in

Body temperature increase slows down pathogen growth and speeds up WBC response.

Interferon – chemical secreted by infected cells to protect other cells from infection.

Specific Immune Defense

Two pathways that will occur1. Humoral – antiobodies are made2. Cell Mediated – destruction of

infected cell or pathogen Key players: Lymphocytes Both pathways are activated when a

pathogen invades the body.

Humoral Antibodies are made to attach to a specific

pathogen’s antigens. Immobilizing pathogen.

Antigens are identifying surface markers. Key players: B cells Key steps:1. B cells recognize antigen2. B cell differentiates into plasma cells3. Plasma cells make/release antibodies.4. B cell differentiates into memory B’s

Antibodies

Y structured molecule made of protein.

Specific receptor sites made to bind to specific antigens.

Binds to the pathogen, flagging it for death

Cell-mediated Immune Response

Key players and steps:1. Killer (cytotoxic) T-cells will multiply and

attack cells with antigen markers.2. Helper T’s will activate killer T’s and

differentiate into memory T’s for future exposures.

3. Suppressor T’s will slow or stop the killer T’s when the attack is under control.

4. Macrophages clean up the mess

The Germ Theory

What is a disease Any change that disrupts normal functions

of the body.What are some agents that produce disease? Bacteria, viruses, fungi, helminths, protistsHow can agents be transmitted? Physical contact, contaminated food, water,

and infected animals (vectors)What methods do we use to fight infections

disease? Antibiotics, vaccines, sanitation, pesticides

Germ theory of Disease

Idea that microorganisms can cause disease

Based on observations from Louis Pasteur and Robert Koch.

Robert Koch developed a set of rules “Postulates” for testing whether or not an organism caused disease.

Koch’s Postulates1. The pathogen should always be found in

the body of a sick organism and not in a healthy one.

2. The pathogen must be isolated and grown in the lab in a pure culture.

3. When purified pathogens are placed in a new host, they should cause the same disease that infected the host.

4. The very same pathogen should be re-isolated from the second host. And it should be the same as the original pathogen.

Immunity Types

Active Immunity – injection of a weak or mild form of pathogen; may make you a little sick. Attenuated form of disease. Natural exposure to pathogen. Long-term immunity.

Passive Immunity – injection of antibodies from another organism; temporary immunity or treatment.

Allergies

An overreaction of the immune system

Mast cells release histamines when allergic antigens attach to it.

Result: itchiness, mucus production, sneezing, watery eyes etc.

Asthma

Narrowing of the air passages by the spasm contractions of the smooth muscle.

Chronic disease Reaction to antigens or stress related.

Other diseasesAutoimmune Disorders Your own immune system is attacking

yourself Production of “antiself” antibodies. Ex. Multiple Sclerosis, Rheumatoid arthritis,

LupusImmunodeficient Diseases Failure of the immune system to develop

normally. Pathogen could be destroying WBC’s Ex: AIDS, boy in the bubble

Chapter 18

Classificiation

Why classify

To organize living things into groups with biological meaning

Taxonomy: the study of classification

Assigning a name Problem: common names can vary among languages Solution: Latin and Greek words are commonly used

to avoid any language issues Problem: When naming by specific traits too many

words are used Solution: Carolus Linneaus developed 2-part naming

system used today called Bionomial Namenclature Rules: 1. Always italicized2. 1st word cap, 2nd lowercase3. Genus is 1st word, species 2nd

Kingdoms and Domains

Modern tree contains six kingdoms and their phyla: Eubacteria, archaebacteria, protista, fungi, plantae, animalia

Domains – newest larges inclusive category devloped from comparing rRNA subunits. Bacteria, Archaea, Eurkarya

Modern Classification Just using appearance can be

misleading New system uses:1. Fossil2. 2. Dissections/Comparative anatomy3. 3. Molecular

similarities/DNA/enzymes4. 4. Evolutionary similarities or

developmental milestones

Molecular Clocks

Comparing DNA segments and looking for mutations in similar genes.

The more dissimilar the genes the longer ago they shared a common ancestor.

Nervous System Notes

CNS

Consists of the brain and spinal cord Recieves sensory input, integrates

and relays information for a response.

Peripheral Nervous System All nerves from spinal cord and cranial

region.1. Sensory nerves pick up stimuli2. Motor nerves send response to muscle

organs Motor functions are controlled bya. Somatic nervous system, conscious

control, skeletal systemb. Autonomic nervous system, involuntary

actions, heart, glands etc.

Meninges

Membranous coverings of the CNS CSF (cerebrospinal fluid) flows here

Cerebrum

Two hemispheres Connected by the Corpus Callosum Wrinkles or folds (gyri) increase

neuron space. Four lobes: frontal, parietd, temporal,

occipital Cerebral cortex – gray matter,

outermost

Cerebellum

Beneath the occipital lobes of cerebrum

Function – coordination of voluntary movements, maintains posture, integrates balance, information (equillbrium)

Brain Stem

Connects the cerebrum to spinal cord Primary life functions Three sections1. Midbrain2. Pons3. Medulla Oblongata

Other structures

Thalamus – main relay station for sensory impulses; general awareness

Hypothalamus – regulates HR, BP, temperature, hunger, sleep, waterfullness, stimulate pituitary

Pituitary gland – major endocrine glands secretes hormones to control other glands/organs.