Download STAAR REVIEW - TEKS BASED

TEKS BASED STAAR REVIEW - 2013
In Biology, students conduct laboratory and field investigations, use scientific methods during investigations, and make
informed decisions using critical thinking and scientific problem solving. Students in Biology study a variety of topics that include:
structures and functions of cells and viruses; growth and development of organisms; cells, tissues, and organs; nucleic acids and
genetics; biological evolution; taxonomy; metabolism and energy transfers in living organisms; living systems; homeostasis; and
ecosystems and the environment.
Knowledge and skills.
(1) Scientific processes. The student, for at least 40% of instructional time, conducts laboratory and field investigations using safe,
environmentally appropriate, and ethical practices. The student is expected to:
(A) demonstrate safe practices during laboratory and field investigations; and
(B) demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of materials.
(2) Scientific processes. The student uses scientific methods and equipment during laboratory and field investigations. The student
is expected to:
(A) know the definition of science and understand that it has limitations, as specified in subsection (b)(2) of this section;
(B) know that hypotheses are tentative and testable statements that must be capable of being supported or not supported by
observational evidence. Hypotheses of durable explanatory power which have been tested over a wide variety of conditions are
incorporated into theories;
(C) know scientific theories are based on natural and physical phenomena and are capable of being tested by multiple independent
researchers. Unlike hypotheses, scientific theories are well-established and highly-reliable explanations, but they may be subject to
change as new areas or science and new technologies are developed;
(D) distinguish between scientific hypotheses and scientific theories;
(E) plan and implement descriptive, comparative, and experimental investigations, including asking questions, formulating testable
hypotheses, and selecting equipment and technology;
(F) collect and organize qualitative and quantitative data and make measurements with accuracy and precision using tools such as
calculators, spreadsheet software, data-collecting probes, computers, standard laboratory glassware, microscopes, various prepared
slides, stereoscopes, metric rulers, electronic balances, gel electrophoresis apparatuses, micropipettors, hand lenses, Celsius
thermometers, hot plates, lab notebooks or journals, timing devices, cameras, Petri dishes, lab incubators, dissection equipment, meter
sticks, and models, diagrams, or samples of biological specimens or structures;
(G) analyze, evaluate, make inferences, and predict trends from data; and
(H) communicate valid conclusions supported by the data through methods such as lab reports, labeled drawings, graphic organizers,
journals, summaries, oral reports, and technology-based reports.
(3) Scientific processes. The student uses critical thinking, scientific reasoning, and problem solving to make informed decisions
within and outside the classroom. The student is expected to:
(A) in all fields of science, analyze, evaluate, and critique scientific explanations by using empirical evidence, logical reasoning, and
experimental and observational testing, including examining all sides of scientific evidence of those scientific explanations, so as to
encourage critical thinking by the student;
(B) communicate and apply scientific information extracted from various sources such as current events, news reports, published
journal articles, and marketing materials;
(C) draw inferences based on data related to promotional materials for products and services;
(D) evaluate the impact of scientific research on society and the environment;
(E) evaluate models according to their limitations in representing biological objects or events; and
(F) research and describe the history of biology and contributions of scientists.
The above three TEKS are non-content. These involve process skills that you should have.
About 22 questions will be dual-coded, meaning that they will reference both a content-based TEKS
and a process skill.
On the pages that follow are the content-based TEKS with some explanation. The explanation
is intentionally short. There should be things that you have to look up to completely review. The
TEKS that are in bold-faced print are what are called Readiness Standards. That means that these
will definitely be tested every year on the STAAR test. The TEKS that are not in bold-faced print
are Supporting Standards which means they were taught with the Readiness Standards but will only
be directly assessed every 2 to 3 years, at random.
There will be approximately 54 questions on the STAAR test with 22-25 coming from the
Readiness Standards and 19-22 coming from the Supporting Standards.
Remember, you MUST pass your EOC exams (EOC = End of Course) in the STAAR system of
testing to graduate. STUDY!!! STUDY!!!STUDY!!!
Cells & Cellular Processes
(4) Science concepts. The student knows that cells are the basic structures of all living things with specialized parts
that perform specific functions and that viruses are different from cells. The student is expected to:
(A) compare and contrast prokaryotic and eukaryotic cells;
All cells have:
 plasma membrane
 cytoplasm
 nucleic acid (DNA)
 cytoskeleton
 ribosomes
Eukaryotes have:
 golgi
 endoplasmic reticulum (smooth & rough)
 vesicles
 vacuoles
 lysosomes
 mitochondria





nucleus
cell wall (some)
cilia or flagella (some)
chloroplasts (some)
linear DNA
Eukaryotes reproduce:
 sexually – gametes, produced through meiosis, fuse to produce genetically different offspring
 asexually – exact copies of one parent are produced through a variety of methods that usually
involve mitosis
Prokaryotes have:
 nucleoid region
 pili
 flagella (some)
 plasmids



capsule (some)
cell wall
circular DNA
Prokaryotes reproduce:
 binary fission – asexual reproduction resembling mitosis
 conjugation – exchange of genetic material through specialized pili; does NOT result in an
increase in the number of cells, so technically not a form of reproduction
(B) investigate and explain cellular processes, including homeostasis, energy conversions, transport of
molecules, and synthesis of new molecules; and
- homeostasis – ability of an organism to keep conditions constant even when the environment
changes
- energy conversions – photosynthesis & cellular respiration; enzymes; metabolism
- transport of molecules – passive transport (diffusion, facilitated diffusion, osmosis); active transport
(sodium-potassium pumps, proton pumps, endocytosis [pinocytosis, phagocytosis], exocytosis)
- synthesis of new molecules – DNA replication, protein synthesis, photosynthesis
(C) compare the structures of viruses to cells, describe viral reproduction, and describe the role of viruses
in causing diseases such as human immunodeficiency virus (HIV) and influenza.
Viruses have:
 nucleic acid (DNA or RNA)
 capsid (protein)
Cells do not have capsids and generally have both DNA and RNA
Viruses reproduce (as studied in bacteriophages):
 lysogenic cycle – life cycle of a bacteriophage in which nucleic acid is injected into a cell where
it becomes a part of the host cell’s DNA; it is replicated with the host cell’s DNA and passed

along to new cells in mitosis; eventually a trigger will cause the viral DNA to be expressed
and the virus enters the lytic cycle
lytic cycle – life cycle of a bacteriophage in which nucleic acid is injected into a cell where it is
immediately translated into more viral parts, which assemble into viruses, and often the cell
bursts when the new viruses are released
HIV – Human Immunodeficiency Virus – virus associated with Acquired Immune Deficiency
Syndrome (AIDS), which results from an impaired immune system due to the destruction of the
helper T cells produced in the thymus; HIV positive is a status indicating that the virus is present in
the body, but has not begun destroying helper T cells, similar to the lysogenic cycle described in
bacteriophages
- a syndrome is a cluster of infections associated with a particular pathogen or disorder, in
this case the HIV is the pathogen
- HIV is a spherical retrovirus; retroviruses have RNA in their capsids that is transcribed
into DNA with the viral enzyme reverse transcriptase; the DNA is then used by the cell
in normal protein synthesis to make more viruses
Influenza – viral infection caused by a spherical virus that mutates rapidly, making it difficult to
immunize against permanently; symptoms include respiratory problems (coughing, difficulty
breathing) and fever, as well as body aches, chills, and lack of appetite
(5) Science concepts. The student knows how an organism grows and the importance of cell differentiation. The
student is expected to:
(A) describe the stages of the cell cycle, including deoxyribonucleic acid (DNA) replication and mitosis, and
the importance of the cell cycle to the growth of organisms;
cell cycle – typical stages cells go through during their lifespan
 interphase – cells spend most of their time in this phase, in which it performs the basic
functions unique to that cell type as well as protein synthesis & cellular respiration; divided
into
o G1 – the cell grows and performs the functions it normally does
o S – synthesis; DNA replication - in the nucleus, resulting in 2 identical copies of each
chromosome joined together by a centromere and called sister chromatids, which are
separated in mitosis
 helicase
 DNA polymerase
 ligase
 leading & lagging strand; 5’3’; Okasaki fragments
o G2 – the cell continues to grow and prepare for cell division
 mitosis – nuclear division with 3 important functions – growth, repair, and asexual
reproduction; 4 phases
o prophase – chromosomes composed of 2 sister chromatids condense and become visible
o metaphase – chromosomes line up at the middle of the cell
o anaphase – sister chromatids are separated
o telophase – sister chromatids reach opposite poles, nuclear membrane reforms,
chromosomes uncoil
 cytokinesis – division of the cytoplasm that usually follows mitosis (or meiosis)
(B) examine specialized cells, including roots, stems, and leaves of plants; and animal cells such as blood, muscle, and
epithelium;
specialized cells are found in the following tissues/organs as described below:
 roots – root cap, zone of cell division, zone of elongation, zone of maturation/differentiation
(including root epithelium with root hairs to increase surface area and water absorption); the





stele (xylem & phloem vascular bundle) runs through the roots; apical meristem (perpetual
embryonic tissue that continuously divides) is present at the root tips & referred to as the zone
of cell division
stems – can be herbaceous (soft) or woody (having lignin and specialized layers such as cork
and bark); have epithelium; the stele is present through the length of the stems; apical
meristem is present at the tips for primary growth
leaves – organs of photosynthesis; typically flat blades to increase light absorption for
photosynthesis; cuticle, epithelium, palisade mesophyll, spongy mesophyll, guard cells, stomata,
xylem, phloem; transpiration
blood – connective tissue in which red blood cells, white blood cells, and platelets are suspended
in plasma; carries nutrients from small intestine and oxygen from alveoli to all cells of the
body where it picks up nitrogenous waste from protein digestion and carbon dioxide from
cellular respiration
muscle – specialized cells involved in movement; made of protein fibers composed of actin and
myosin that slide past each other, allowing muscle tissue to contract and relax; 3 types
o smooth – involuntary, spindle-shaped cells that line the tracts of the body (such as the
digestive tract) and is involved in moving substances (such as food) through a system
o skeletal – voluntary, striated tissue that is often multinucleate; it is attached to bones
with tendons and allows organisms to move, particularly their limbs and other jointed
locations (like the jaw)
o cardiac – involuntary, branched, striated tissue that is joined by specialized structures
called intercalated disks that allow electrical messages to be passed to every cell so that
it contracts in unison; found only in the heart
epithelium – tissue composed of epithelial cells that covers the inside and outside of organisms;
skin is epithelium, as is the lining of the digestive, respiratory, reproductive, and excretory
tracts; offers protection from substances entering or leaving an organ due to tight junctions
that join the cells together, as well as the source of specialized structures such as ciliated cells
of the respiratory tract
(C) describe the roles of DNA, ribonucleic acid (RNA), and environmental factors in cell differentiation; and
 every cell has all of the chromosomes with all of their genes
 cells are different depending on which genes are expressed and which genes are not expressed
 the decisions of which genes are expressed and which genes are not is made early in the
embryonic development, based on environmental signals that result in chemical groups being
added onto parts of the chromosome that prevents some genes from ever being expressed
 embryonic stem cells are cells that still have the ability to become any kind of cell because
they have not had any of the chemical groups bonded onto their chromosomes; totipotent
 adult stem cells are cells such as those in the bone marrow that have the ability to become
several different kinds of cells because they have had some genes disabled, but not enough to
make them a particular type of cell; pleuripotent
(D) recognize that disruptions of the cell cycle lead to diseases such as cancer.
 checkpoints are places in the cell cycle where chemical signals either pause the cell cycle or
force it to continue to the next stage; these chemical signals are coded for by genes; when these
genes are mutated and the signals are either produced in excess (like a stuck accelerator) or
not produced enough (like broken brakes), the cell cycle goes out of control
 when the cell cycle is out of control, cancer results
Molecular Genetics & Heredity
(6) Science concepts. The student knows the mechanisms of genetics, including the role of nucleic acids and the
principles of Mendelian Genetics. The student is expected to:
(A) identify components of DNA, and describe how information for specifying the traits of an organism is
carried in the DNA;
- traits are coded for by sequence or order of the nucleotides in the DNA (the GCTA)
- DNA is composed of nucleotides held together by hydrogen bonds across the double helix (A-T, G-C)
- a nucleotide is composed of a 5-C sugar (deoxyribose or ribose), a phosphate group, and a nitrogen
base (GCATU)
- the sides of the DNA molecule are held together with covalent bonds between the sugar of one
nucleotide and the phosphate group of another nucleotide
(B) recognize that components that make up the genetic code are common to all organisms;
- all organisms have the same nucleotides, and the same sets of 3 nucleotides (codons in the mRNA)
almost universally code for the same amino acids
(C) explain the purpose and process of transcription and translation using models of DNA and RNA;
- the purpose of gene expression or protein synthesis is to make proteins
- the purpose of transcription is to make an RNA version of the DNA sequence of a particular gene
so that the message can leave the nucleus
- the purpose of translation is to read the nucleotides 3 at a time (codons) that will result in a specific
sequence of amino acids being assembled
- transcription is in the nucleus while translation is in the cytoplasm
- transcription and RNA processing result in an mRNA molecule ready to be read
- translation occurs when the mRNA molecule and a ribosome join together and tRNA molecules
bring amino acids to the complex in the order specified by the nucleotide sequence, read three at a
time as codons
- using models most likely refers to pictures
(D) recognize that gene expression is a regulated process;
- genes are not continually expressed in cells
- only cell products that are needed are made at any particular time; this has been wellstudied in bacteria and documented in models of the lac operon (makes the enzymes that
break down lactose only when lactose is present) and trp operon (makes the enzymes that
synthesize tryptophan—an amino acid-- when tryptophan is not present)
- in humans, transcription factors (cell signals that reach the nucleus) turn genes on and off
as needed in response to changes in the environment (body of the organism); the cell
signals can be growth factors, hormones, or other molecules; important in maintaining
homeostasis
(E) identify and illustrate changes in DNA and evaluate the significance of these changes;
 mutations – changes to the original DNA sequence that often result in changes to the protein
product and therefore to the phenotype of the organism
 changes to the DNA sequence may involve a point mutation – a single change to a single
nucleotide
o frame-shift – mutation that results in a change in the codons from the point of the
mutation to the end of the protein
o insertion – a nucleotide is added into the DNA sequence
o deletion – a nucleotide is lost from the DNA sequence
o substitution – a nucleotide is exchanged for another nucleotide
o silent mutation – a change in the sequence (usually to the 3rd nucleotide) does not result
in a change in amino acid
nonsense – the mutation results in a premature stop codon and an extremely short and
nonfunctional protein
o missense – the mutation results in a change in every amino acid from one point one so
that the protein is formed but it is not the same protein and is most likely
nonfunctional
changes to the DNA may involve the chromosome – pieces of the chromosome are involved
o deletion – a piece of a chromosome is missing
o inversion – a piece of a chromosome is reversed
o duplication – a piece of a chromosome is repeated
o translocation – a piece of a chromosome is broken off and attaches to another nonhomologous chromosome
o

(F) predict possible outcomes of various genetic combinations such as monohybrid crosses, dihybrid
crosses and non-Mendelian inheritance;
 phenotype
 incomplete dominance
 genotype
 codominance
 dominant
 sex-linked (on the X chromosome)
 recessive
(G) recognize the significance of meiosis to sexual reproduction; and
- meiosis results in the production of gametes (sex cells; eggs and sperm) that are haploid;
sexual reproduction involves the combination of gametes to form a diploid zygote that can
divide by mitosis to produce a unique organism
- variation in organisms results from crossing over (prophase I), independent assortment
(anaphase I and II), and random fertilization
- genetic variation in a population is important in sexual reproduction
(H) describe how techniques such as DNA fingerprinting, genetic modifications, and chromosomal analysis are used to
study the genomes of organisms.
 DNA fingerprinting – produced with gel electrophoresis techniques; unique banding
pattern produced when a restriction enzyme is used to create DNA fragments that sort
by size with the smallest moving the farthest from the starting point; used to determine
identity, family relationship, and to locate genetic mutations
 genetic modifications – other changes to genes that allow scientists to study their function
and determine their location, as well as how to correct errors in faulty genes (mostly in
the future), or control the expression of genes to create a desired product (insulin, growth
hormone), or to make changes in an organism (again, mostly in the future)
 chromosomal analysis – often done with a karyotype – a picture of a person’s chromosomes
arranged in order from longest to shortest; can determine sex, presence of chromosomal
abnormality (like Down syndrome), number of autosomes, number of sex chromosomes,
gamete or somatic cell
Evolution & Populations
(7) Science concepts. The student knows evolutionary theory is a scientific explanation for the unity and diversity of
life. The student is expected to:
(A) analyze and evaluate how evidence of common ancestry among groups is provided by the fossil record,
biogeography, and homologies, including anatomical, molecular, and developmental;
- fossil record – the remains of an organism left as impressions in sedimentary rock, in amber, or
preserved in some other way can be studied for similarities in anatomy; as sediment is deposited, the
older layers become deeper and newer fossils are laid on top; dating the rock that the fossils are in
and using that as a reference to date the fossils is called relative dating; dating the actual fossil is
called radiometric dating and uses the mathematical application called half-life to determine the age
of the rock; organic remains are dated using the ratio of C-14 and C-12; common ancestry of groups is
shown in the fossil record when evidence of divergence can be seen in the fossil record
- biogeography - the study of the distribution of species, organisms, and ecosystems in grographic
space and through geological time; organisms and biological communities vary in a highly regular
fashion along geographic gradients of latitude, elevation, isolation, and habitat area;
http://en.wikipedia.org/wiki/Biogeography
- homologies – evidence of evolutionary relationship based on anatomy, molecular, or developmental
data
- anatomical homology – same parts, different function; classic example is forelimb of
vertebrates which are all composed of the same basic bones, which vary in shape as the limb has been
adapted for various forms of locomotion, including swimming, flying, running, walking, and
brachiating – results due to divergent evolution; usually discussed with the term anatomical analogy
in which parts that are NOT of the same embryological origin have been adapted for the same
function; common example is the wing of an insect and the wing of a bird, or the dorsal fin of a
shark, a dolphin, and an ichthyosaur – results due to convergent evolution; vestigial structures are
usually mentioned with this as well – structures that used to have a greater importance/ use but are
physically reduced and are unimportant in the life of the organism, such as the claws of a boa, the
pelvis of a whale, the appendix in a human
- molecular homology – looking at similarities in the nucleotide sequence or amino acid
sequence of molecules with common functions in animals; the similarities in the genetic code and
resulting proteins are evidence of evolutionary relationship; the more similar the sequence, the more
recently they shared a common ancestor; hemoglobin and proteins involved in the electron transport
system (cytochromes) are commonly studied
- developmental homology (embryology) – looking at similar structures and processes in
embryological development, including early stages (zygote, blastula, gastrula, neurula) and later
similarities, such as somites, pharyngeal slits, dorsal hollow nerve cord, notocord, and postanal tail;
the sequence in which structures develop and the genes ( Hox genes; homeotic genes) that control
development could be included
( B) analyze and evaluate scientific explanations concerning any data of sudden appearance, stasis, and sequential nature
of groups in the fossil record;
- sudden appearance – can be attributed to punctuated equilibrium usually associated with
catastrophic events or rapid environmental change, or to the fact that certain conditions
must be present in order for a fossil to form
- stasis – is explained as evidence of gradualism associated with stable environments or
geologic periods
- sequential nature of groups – evidence of evolutionary relatedness and the fact that fossils
are laid down in chronological order with the oldest ones in the bottom-most layers and the
newest fossils closer to the surface of the earth
(C) analyze and evaluate how natural selection produces change in populations, not individuals;
- individuals can grow, mature, and develop but they cannot evolve! Evolution is best defined as a
change in gene frequency. An individual’s genes do not change in their lifetime, but the number of
organisms with a particular genotype (phenotype) can change within a population over time as
traits that better adapt an individual to the environment appear by chance and increase the
number of fertile offspring left behind with that same genotype (phenotype)/ adaptation
- evolution occurs at the level of the population! Hardy-Weinberg:
- evolution is NOT occurring in a population if
- mating is random
- the population is large
- there’s no migration (no emigration or immigration)
- there’s no mutation
- there’s no natural selection
(D) analyze and evaluate how the elements of natural selection, including inherited variation, the potential of a population
to produce more offspring than can survive, and a finite supply of environmental resources, result in differential
reproductive success;
- inherited variation – some organisms have unique traits (new alleles) that form due to
mutation that adapt them better to their current environment and results in them having more
fertile offspring that also inherit the adaptive trait
- most organisms have more offspring than can survive; this insures that those that do survive
are the strongest and most fit for the environment
- limited resources go into factoring carrying capacity (K) of a particular environment; the
strongest, fastest, best adapted of all offspring get most of the resources (food, water, space, mates)
and thus survive to reproduce
- differential reproductive success – refers to the fact that different organisms in the same
population have different fitness values where fitness is measured by the number of fertile offspring
that survive to reproduce
(E) analyze and evaluate the relationship of natural selection to adaptation and to the development of
diversity in and among species; [and]
- natural selection – process by which organisms that have the most favorable traits
(adaptations) survive to reproduce more often and in greater numbers than those that have less
favorable traits
- diversity in and among species – within a species, populations may live in differing
environments making the most favorable traits in one area a less favorable trait in another area,
resulting in differences between the populations and leading to variation in the species; among
species, variation results from different ways of adapting to an environment, such as adaptations to
a particular climate
(F) analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and
recombination ; and [.]
- genetic drift – changes in gene frequency due to random chance; examples include
- population bottleneck – the original population is drastically reduced in number,
generally due to a natural disaster or disease so that the surviving members may or may not
represent all of the alleles previously present in the population in the same frequencies as
before; cheetahs
- founder effect – the original population is reduced by a few individuals that are
geographically removed from the original population by wind, water current, or some other
event and start a new population; the new population is most likely different in the alleles
represented and the frequencies of those alleles; Amish in the USA
- gene flow – the movement of genes (alleles) in and out of a population due to immigration or
emigration that changes the gene frequencies
- mutation – random event in which alleles are created due to a change in the genetic code
(DNA sequence of nucleotides); usually a negative thing for the organism
- recombination – occurs in sexual reproduction when crossing over, independent assortment
and random fertilization create new and unique combinations of genes in offspring
(G) analyze and evaluate scientific explanations concerning the complexity of the cell.
- theory of endosymbiosis – the theory that mitochondria and chloroplasts were originally
independently living bacteria that were engulfed by a large eukaryotic cell but not phagocytized
(digested); what was once symbiosis is now thought of as a single unit of life – a eukaryotic cell
Classification & Taxonomy
( 8) Science concepts. The student knows that taxonomy is a branching classification based on the shared
characteristics of organisms and can change as new discoveries are made. The student is expected to:
(A) define taxonomy and recognize the importance of a standardized taxonomic system to the scientific community;
- taxonomy – science of naming and classifying
- standardized taxonomic system – binomial nomenclature & 3 domain/ 6 kingdom system;
Latin; Genus species; hierarchical – DKPCOFGS; organisms in the same level share a defined set of
characteristics
(B) categorize organisms using a hierarchical classification system based on similarities and differences
shared among groups; and
- may be based on a table of data in which you have to decide which organism is not related to
the rest, which 2 organisms are the most closely related, or may be a description of a “new” organism
that needs classifying; you MUST know the characteristics of the organisms in the 3 domains and in
the 6 kingdoms
( C) compare characteristics of taxonomic groups, including archaea, bacteria, protists, fungi, plants, and animals.
- These are the 6 kingdoms; be sure you can differentiate among them!
Biochemistry
(9) Science concepts. The student knows the significance of various molecules involved in metabolic processes and
energy conversions that occur in living organisms. The student is expected to:
(A) compare the structures and functions of different types of biomolecules, including carbohydrates,
lipids, proteins, and nucleic acids;
- carbohydrates – CHO in a ratio of 1:2:1; sugars; mono-, di-, and poly-saccharides;
glucose=C6H12O6; can be for energy storage (starch and glycogen) or structure (cellulose and
chitin)
- lipids – group of compounds that act as energy storage or informational molecules,
including phospholipids, pigments (chlorophyll), fatty acids, and steroid hormones
(testosterone & estrogen); often have both polar (hydrophilic) and nonpolar (hydrophobic)
regions; can be saturated (with hydrogen; no double or triple bonds) or unsaturated (at
least one double or triple bond)
- proteins – 3rd group of organic compounds composed of amino acids joined together with
peptide bonds to form di- and polypeptides; amino acid general structure= central carbon
with an amino group (-NH2), a carboxylic acid group (-COOH), a hydrogen (-H), and a
variable group (-R); proteins can be structural such as collagen, keratin, and silk or
carrier molecules such as hemoglobin & insulin, receptors in the cell membrane, or
enzymes (as well as other functions); proteins have 4 levels of structure: primary – amino
acid sequence held together by peptide bonds; secondary – alpha helices or beta pleated
sheets held together by hydrogen bonds; tertiary – folding into a complex 3D conformation
due to hydrophobic interactions, ionic bonds, S-S bonds, and hydrogen bonds between the
R-groups of the amino acids in the sequence; quaternary – more than one chain joined
together to make a functional protein, such as the 4 subunits in hemoglobin
- nucleic acids – deoxyribonucleic acid & ribonucleic acid; informational molecules that
store and communicate the genetic information in a cell through the sequence of
nucleotides; nucleotides are called by the name of the nitrogen base they contain (adenine,
thymine, guanine, cytosine, & uracil); nucleotides are composed of a 5-C sugar, a nitrogen
base, and a phosphate group; nucleotides are held together by covalent bonds along the
sugar-phosphate sides and hydrogen “bonds” across the middle (DNA only)
- polymers can be formed through dehydration synthesis reactions (water is formed when a
monomer is added to the larger molecule); polymers can be broken down through
hydrolysis (water is split and the –OH is added to the newly freed end of one molecule and
the –H to the newly freed end of the other molecule)
(B) compare the reactants and products of photosynthesis and cellular respiration in terms of energy and matter; [and]
- C6H12O6 + 6O2  6CO2 + 6H2O + ATP
- cellular respiration is an exergonic reaction overall, releasing the energy in glucose
which is then captured and temporarily stored in ATP for cellular use; ATP production occurs
primarily in the mitochondria; in general, a series of catabolic reactions
- cellular respiration in eukaryotes begins in the cytoplasm with the splitting of glucose
into 2 pyruvates, producing 2 NADH and 2 ATP (net); in the presence of oxygen the pyruvates then
enter the mitochondria where they immediately have a carbon cleaved off to form CO 2 and the acetyl
group left combines with CoA; acetyl CoA then combined with OAA to form the 6-carbon citrate in
the first step of the Krebs cycle; in the Krebs cycle NADH, FADH2, and ATP are formed, along with
4 more molecules of CO2, regenerating the OAA; the NADH & FADH2 formed then enter the electron
transport chain where each molecule of NADH produces 3 ATP and each molecule of FADH 2
produces 2 ATP, for a rough total of 36 ATP (and 6 molecules of CO 2) from one molecule of glucose
- when oxygen is not present, the pyruvate produced is either converted into lactic acid
(vertebrate muscle) or ethanol and carbon dioxide (yeast and plants) to regenerate NAD+ so that
glycolysis can continue
- 6CO2 + 6H2O + Esunlight  C6H12O6 + 6O2
- photosynthesisis an endergonic reaction overall, storing the light energy from the sun as
chemical energy in glucose; these reactions occur in the chloroplast in eukaryotic organisms; in
general, a series of anabolic reactions
- photosynthesis in eukaryotes begins when light strikes photosystems II and I, producing ATP,
NADPH, and splitting water (photolysis); the ATP and NADPH are then used in the Calvin cycle to
fix carbon from carbon dioxide into a series of molecules that results in the production of one
molecule of glucose for every 6 carbon dioxide molecules that enter the cycle; ribulose bisphosphate
(RuBP) is the 5-C molecule that the CO2 is fixed to first in the cycle with the enzyme ribulose
bisphosphate carboxylase (RuBisco)
(C) identify and investigate the role of enzymes ; and [.]
- enzymes are molecules, generally proteins, that increase the rate of reaction by lowering the
activation energy but are not themselves changed or used up
- enzymes are denatured (lose their tertiary and quaternary conformation) by changes
(especially increases) in temperature and changes in pH
- enzymes make reactions happen “easier” by “stressing” the bonds holding together a molecule
so it will break with less energy needed, or by holding together 2 or more molecules in perfect
orientation so that bonds will form between them with less energy needed
- the reactants have more energy than the products in an exergonic reaction; the reactions
have less energy than the products in an endergonic reaction
( D) analyze and evaluate the evidence regarding formation of simple organic molecules and their organization into long
complex molecules having information such as the DNA molecule for self-replicating life.
Systems & Homeostasis
(10) Science concepts. The student knows that biological systems are composed of multiple levels. The student is
expected to:
(A) describe the interactions that occur among systems that perform the functions of regulation, nutrient
absorption, reproduction, and defense from injury or illness in animals;
- regulation – negative feedback (like a thermostat) is one of the most common forms of
regulation; feedback inhibition is used to regulate many reactions (the product inhibits one
of the first steps in the sequence); positive feedback is used for some events such as
childbirth
o nervous system – regulates many responses based on stimuli from the environment
using neurotransmitters & electrical signals
o endocrine system – regulates many responses based on stimuli from the
environment using chemical signals (hormones) that act as a distance
- nutrient absorption – occurs in the villi of the small intestine directly into the circulatory
system at the capillaries that enter
- reproduction – the endocrine system regulates the reproductive system through hormonal
action; the nervous, muscular, & circulatory systems also are connected to reproductive
systems throughout the animal kingdom
- defense from injury or illness – the integumentary system provides the first level of
protection from both injury and illness; the immune system provides the second and third
levels of defense; review specific and nonspecific defenses; the circulatory system &
lymphatic system are closely tied to the immune system as well
(B) describe the interactions that occur among systems that perform the functions of transport,
reproduction, and response in plants; and
- transport – involves the vascular system of plants composed of xylem and phloem and
supporting cells; xylem carries water and dissolved solutes (nutrients) from roots to shoots;
phloem carries sugars from source to sink (where glucose is made or stored to where it is
needed for cellular respiration)
- reproduction – pteridophytes (ferns) reproduce with spores; gymnosperms reproduce with
gametes located in pollen and seeds that come from cones; angiosperms reproduce with
gametes located in pollen and seeds that come from anthers and ovules in flowers; this
takes a lot of energy that may be obtained from stored sugars (starch) moving through
phloem
- responses in plants - primarily involve tropisms – these are hormonally controlled and
include phototropism, geotropism (gravitropism) and thigmotropism; the hormones include
auxins that move through the vascular system of the plant and through the tissues to the
cells upon which they act
(C) analyze the levels of organization in biological systems and relate the levels to each other and to the whole system.
- the lowest level of organization in a biological system is technically the cell (cells are
considered to be alive); cells are made of molecules arranged in organelles; the molecules
are made of atoms
- cells are arranged into tissues, tissues into organs, organs into organ systems and organ
systems into organisms
- organisms make up a population; populations comprise a species; species make up a
community; communities make up ecosystems (along with the physical environment);
ecosystems make up the biosphere
( 11) Science concepts. The student knows that biological systems work to achieve and maintain balance. The student
is expected to:
(A) describe the role of internal feedback mechanisms in the maintenance of homeostasis;
- homeostasis is the ability of an organism to maintain balance even when the external
environment changes; organisms do this by responding to stimuli with mechanisms to
move internal conditions back toward an acceptable range
- example, blood sugar – regulated by negative feedback; blood sugar is supposed to be in a
range of about 90 to 110 or so; when blood sugar levels drop, glucagon is released from the
pancreas which signals cells in the liver and muscle to break down glycogen and release
the glucose into the blood; when blood sugar levels rise, insulin is released from the
pancreas which signals cells in the liver and muscles to take up glucose and store it as
glycogen
- feedback inhibition is also used to help maintain homeostasis at the cellular level; in a
biological pathway the product is often an inhibitor of one of the first steps in the
pathway to prevent unnecessary production of materials the cell doesn’t need
(B) investigate and analyze how organisms, populations, and communities respond to external factors;
- organisms – respond with changes in their behavior, primarily taxis (movement toward or
away from the stimulus) or kinesis (random movement); ex) Euglena will move toward the light to
increase photosynthesis; this is positive phototaxis; ex) puppies just run randomly when they hear a
noise; this is kinesis
- populations – changes in populations may include changes in the gene frequencies, but
populations also respond to external factors such as seasonal cues that trigger migration, mating
behaviors, or food caching
- communities – large-scale events like drought, flood, fire, etc would change communities,
possibly permanently; communities “respond” through the loss or gain of species and subsequent
changes to the interactions among those species
(C) summarize the role of microorganisms in both maintaining and disrupting the health of both organisms and
ecosystems; and
- organism – maintaining health – there are bacteria on our skin that outcompete harmful
bacteria & fungi; there are bacteria in our intestines that help promote digestion and the production
of vitamin K
- disrupting health – parasitic bacteria, protists, and fungi steal nutrients and
disrupt normal cell processes
- ecosystems – maintaining health – microorganisms are principal decomposers, the basis of
some food chains, and key to the nitrogen cycle; many are also symbionts
- disrupting health – if microorganisms are missing from ecosystems, the
negative impacts include disruption to nutrient cycling, interruption of food chains, and the possible
loss of other species
(D) describe how events and processes that occur during ecological succession can change populations
and species diversity.
- ecological succession – process through which ecosystems change due to the actions of
organisms; those actions alter the environment in a way that the organisms are no longer
well-adapted to the environment and they lose out to better competitors; the organisms
that have replaced them then cause more change in the environment and are
consequently replaced by other, better adapted species, etc etc ex) lichens can break down
the exposed rock following a glacier receding, creating soil that seeds can germinate in;
the plants provide habitat for insects and small animals; the actions of these organisms
create conditions for ideal for larger plants and organisms until eventually large
hardwoods have created a forest with many more species than originally existed
(diversity)
- key terms include pioneer species, primary succession, secondary succession, and climax
community
Ecosystems
( 12) Science concepts. The student knows that interdependence and interactions occur within an environmental
system. The student is expected to:
( A) interpret relationships, including predation, parasitism, commensalism, mutualism, and competition
among organisms;
predation – when a predator (typically a carnivore) kills and eats another organism (its prey)
parasitism – symbiotic relationship in which the host organism is harmed and the parasite benefits
commensalism – symbiotic relationship in which the host organism is not affected by the presence of
another organism living on or in it
mutualism – symbiotic relationship in which the host organism benefits from the presence of another
organism living on or in it, and so does the other organism
competition – limiting factors (resources) in an environment result in some species not getting
enough of the resources needed (interspecies competition), or in some organisms not getting enough of
the resources needed while others are within a population (intraspecies competition); ex) interspecies
competition – barnacle example; birds with overlapping habitats partitioning their niches so they
can get most of what they need; ex) intraspecies competition – larger organisms eating most of a kill,
male deer competing for mates through displays of strength when they rut (hit horns/ heads
together)
( B) compare variations and adaptations of organisms in different ecosystems;
- think about how different organisms are specifically adapted to different biomes – how is a
seal adapted for life as a marine predator; how is an arctic fox’s adaptations to surviving
in such a cold environment different from a desert fox’s adaptations to surviving in such
a hot, dry environment; how do these two species of fox differ from the fox that lives in
temperate forests
(C) analyze the flow of matter and energy through trophic levels using various models, including food
chains, food webs, and ecological pyramids;
- remember that nutrients cycle and energy flows in/through ecosystems
- food chains – not a realistic picture of how organisms obtain energy and nutrients from
other organisms because most organisms have more than one food source; the arrows represent
energy flow
- food webs – a more realistic picture of how organisms obtain energy and nutrients from
other organisms in an ecosystem
- ecological pyramids – show the trophic levels beginning with producers and ending with the
top consumers (generally predators); reflect the 10% transfer of energy from one level to the next;
since so little energy is moved from one level to the next, the number of organisms that can be
supported (the biomass) decreases from level to level
(D) recognize that long-term survival of species is dependent on changing resource bases that are limited;
- for a species to survive they have to be adaptable; if one year there are lots of mice and a
few squirrels, the owls will eat mostly mice even if they prefer squirrels; if the next year
there are no mice or squirrels but plenty of lemmings, then they better eat lemmings
(E) describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting
these cycles; and
- carbon cycle – carbon dioxide (CO2) is the source of all carbon in an ecosystem; it is taken
in in the process of photosynthesis and fixed into glucose (sugar; carbohydrate); when the
plant is eaten or uses some of its own stored sugars, the carbon it has stored in its body
(starch or cellulose) is used for cellular respiration which breaks down the glucose and
releases the carbons as carbon dioxide; calcium carbonate is a significant source of stored
carbon in the shells of many marine invertebrates; these deposits of calcium carbonate will
erode with time and release CO2 into the water; dead and decomposing organisms contain
-
carbon that may be released in the process of decomposition, releasing CO2; fossil fuels
release CO2 when they are burned; disruptions to the carbon cycle increase or decrease the
amount of CO2 in the atmosphere, which affects global temperatures due to the greenhouse
effect; deforestation and burning fossil fuels both increase the amount of CO 2 (referred to as
a greenhouse gas); planting trees and creating other green spaces as well as using
alternative energy sources decrease the amount of CO2
nitrogen cycle – the action of several different species of soil bacteria convert nitrogencontaining compounds from one form to another, until they are eventually converted to
nitrates which plants can take up and incorporate into important compounds such as
amino acids for making proteins and nucleotides for making nucleic acids; nitrogen is 78%
of the atmosphere, but only a few species of bacteria can fix it into the soil; disrupting the
nitrogen cycle affects the health of plants, resulting in a loss of producers at the base of the
food web and therefore impacts all organisms in the ecosystem
(F) describe how environmental change can impact ecosystem stability.
- ecosystems are the community plus the physical environment; changes to the environment
make some organisms/species less well-adapted for its role in the ecosystem while other
organisms/ species become more well-adapted; the species with the best adaptations will
outcompete the other organisms; losing or gaining species affects the stability of an
ecosystem because it will disrupt food webs