AP Psychology Ch6 vocab with brief notes

Chapter 6 Vocabulary

learning – when experience modifies pre-existing behavior/understanding; simplest form = learning about individual stimuli
two major kinds
1) classical conditioning
2) operant conditioning

Habituation = two interacting processes
A process: fixed, automatic, emotional, unlearned reponse
B process: slower reaction, triggered by onset of A and counteracts its effects (compensate and decrease)

unconditioned stimulus (UCS) = stimulus that elicit response without conditioning --> unconditioned response (UCR) = unlearned reaction
conditioned stimulus (CS) = new stimulus paired with unconditioned stimulus --> conditioned response (CR) = response it comes to elicit

Stimulus generalization occurs when a stimuli similar to a conditioned stimulus create a similar conditioned response, although to a lesser degree. The more similar the new stimulus to the conditioned stimulus, the stronger the conditioned response.

Operant conditioning = same as instrumental conditioning, except with emphasis on organism learning response through operating on environment; behavior changed through consequences
operant – response that has effect on world, operates on environment (i.e. child tells parents he is hungry and thus influences appearance of food)
reinforcer – increases probability that operant behavior will occur again
positive = strengthen response when pleasant or positive stimulus occurs after behavior
negative = strengthen response through removal/termination of something unpleasant after behavior

learned helplessness – tendency to give up any effort to control the environment
latent learning – not evident when it first occurs
cognitive map – mental representation of particular spatial arrangement

1. Habituation is a form of learning that occurs when our responsiveness to unchanging stimuli over time decreases as a result of our adapting to that stimuli.

2. Classical Conditioning is a basic form of associative learning, when a neutral stimulus is repeatedly paired with a stimulus that naturally triggers a reflexive response, until the formerly neutral stimulus evokes a similar response to the reflex without the reflex triggering stimulus.

3. Extinction is when a conditioned response gradually over time disappears when the unconditioned stimulus (which originally triggered an automatic response without conditioning) is no longer paired with the conditioned stimulus (which originally triggered only a neutral reaction or none at all).

4. If, after the conditioned response has disappeared or become extinct, the conditioned stimulus and unconditioned stimulus are paired again, reconditioning occurs, and the conditioned response will return to its original strength very quickly after a short period of time (less then the original conditioning).

5. Spontaneous recovery is when an extinguished conditioned response will temporarily occur again when the conditioned stimulus is present, even though the unconditioned stimulus is absent. This reappearance of the conditioned response after extinction does not require further conditioned stimulus and unconditioned stimulus pairings. In fact, the longer the time between the extinction of the conditioned response and the re-presentation of the conditioned stimulus, the stronger the recovered conditioned response generally is.

6. Stimulus discrimination is when organisms differentiate among similar stimuli, so that not all stimuli will result in a conditioned response through stimulus generalization.

7. Second-order conditioning is when a conditioned stimulus acts like an unconditional (natural) stimulus and creates a conditioned stimuli out of associated events.

8. The Law of Effect states that a response will be more likely to occur in the presence of a certain stimulus if that that response was previously followed by satisfaction or reward when that same stimulus was present. Conversely, responses that produce discomfort are less likely to be performed again in the presence of that stimuli.

9. Instrumental Conditioning is the type of learning in which certain responses are strengthened and more likely to occur in the future because those response are instrumental in producing rewards.

10. Positive Reinforcement works like a reward, and is when a response is strengthened or increased because pleasant or positive stimuli occurs after certain behavior. The behavior will thus be repeated because it causes desirable outcomes.

11. Negative Reinforcement occurs when unpleasant stimuli are removed or terminated upon a certain response or behavior, and thus strengthen the likelihood that such behavior will be repeated in the future.

12. Escape Conditioning occurs when an organism learns to respond a certain way in order to end or terminate an aversive stimulus or negative reinforcer.

13. Avoidance Conditioning is when an organism makes a connection between a certain stimulus and an event that is linked with that stimulus. When the stimulus occurs or becomes present, the organism thus reacts or respond to the signal so as to avoid or prevent the exposure to a certain aversive event. This conditioning is a mix of both classical and operant conditioning because it involves both a conditioned stimulus (pairing signal with unwanted event) and the reinforcement through consequences.

14. Punishment works in the opposite manner of positive and negative reinforcement by decreasing the likelihood that behavior will occur by following a certain operant behavior with an aversive or unpleasant stimulus or deprivation of a pleasant stimulus (penalty).

15. Discriminative stimuli are stimuli that signal whether reinforcement (reward) is available if a certain response is made. They allow organisms to learn what is appropriate in certain situations and inappropriate in others, as the organisms learn to make particular responses in the presence of one stimulus but not another.

16. Shaping reinforcement of behavior through successive approximations. Reinforcement drives the responses closer to the desired response, through steps.

17. Primary reinforcers are inherently rewarding events or stimuli. They may cause problems, however, because if the reinforcement is something like food, over time it will become less powerful, because hunger and desire for the food will diminish. Time will also be lost to consumption. Thus, previously neutral stimuli called secondary reinforcers are used. Secondary reinforcers (aka conditioned reinforcers) are paired with naturally reinforcing stimuli and then become reward-like in themselves and are learned to be liked.

18. Vicarious Conditioning is a type of observational learning when seeing or hearing the consequences of others’ behavior influences one’s own behavior.

19. Operant Conditioning is similar to instrumental conditioning, except that it emphasize how an organism learns to responses certain ways through operating on its environment. Behavior changed through consequences.

20. Observational Learning occurs through watching others, and is efficient and adaptive way of learning socially. Children are generally very easily influenced by adults and peers who they see as models for “appropriate behavior.”

French Prompt on French vs. American Universities

La Vie Universitaire – Parlons-en!



       Le système universitaire aux Etats-Unis est très different que le système française. Quands les étudiants viennent s’inscrire, ils vont à leur bureau des conseillers. Les conseillers aident les étudiants à établir leurs emploi du temps. Aux Etats-Unis, quand on est inscrit, c’est pour le semestre. Les étudiants peuvent lui parler des classes et des programmes, ensuite, les conseillers vais lui aider à prendre des décisions sur le plan de cours. Les conseillers ont des dossiers, des grands horaires (grades, transcripts), mais tout se fait pas ordinateur. Les étudiants ne doivent que remplir les formalités.

       Dans l’université americain, il y a des cours obligatoires pour tout les élèves. Ces cours sont généraux, comme l’anglais et l’histoire, mais il y a aussi des cours pour préparer une carrière, comme la biologie ou le calcul.

       Le système dépend des devoirs, des contrôle connaissances, et des examens. Les élèves doivent surive ses cours régulièrement, faire ses devoirs, et subir d’épreuves périodiques. Il y a aussi des examnes partiels et des grands examens au fin de ces cours.

AP Biology Ch22 Objectives

Ch 22 – Descent with Modification: A Darwinian View of Life

The Historical Context for Evolutionary Theory
1. Darwin’s belief in evolutionary change was based upon the mechanism of natural selection. Natural selection is when a population changes over time due to the fact that individuals with more desirable traits are better equip to produce more offspring and thus pass on their genes. Consequentially, over time, an accumulation of inherited characteristics allow a species to adapt, making organisms more fit for survival and reproduction (in their environment).

2. Evolution is defined as the changes in genetic composition of a population over time. It can refer to biological diversity (for example, in terms of appearance). Adaptation is the increased ability or a population to survive and reproduce in its environment as a result of accumulated inherited traits.

3. Aristotle, an early Greek philosopher, proposed the scala naturae—a ladder of increasing complexity upon which all organisms could be organized, with a permanent species on each rung. Because Aristotle did not believe in evolution, his set up did not allow for organisms to adapt or change.
Carolus Linnaeus, a physician and botanist from Sweden, came up with another method of organization, which is called taxonomy. This system classifies species into increasingly complex categories and names them based on these groups. The genus and species create the binomial “label.” Similar species are arranged in increasingly general categories. Linnaeus believed that similarities between species showed the pattern of their creation.

4. Georges Cuvier, a French paleontologist/anatomist, promoted the idea of catastrophism, that species could be destroyed by natural disasters and thus create boundaries between strata. These stripped lands would be repopulated by species from unaffected areas.
Scottish geologist James Hutton proposed the theory of gradualism, which states that profound geological changes take place through the cumulative effects of slow, continuous processes identical to those currently going on.
Geologist Charles Lyell came up with uniformitarianism, the idea that geological processes have not changed throughout Earth’s history.

5. Jean-Baptiste de Lamarck, a French biologist, believed that the mechanisms for evolutionary change were use and disuse and inheritance of acquired characteristics. He based these two principles upon observations he made on the fossil invertebrate collection at Paris’s Natural History Museum, where he compared current species to the fossils. While doing so, Lamarck found what appeared to be several lines of descent from older to younger fossils, which eventually led to a modern species.
Use and disuse is the idea that essential parts of an organism that are constantly used become larger and stronger, while unnecessary parts deteriorate. Inheritance of acquired characteristics states that offspring can inherit modifications from their parents that were acquired during their lifetime. Lamarck believed that the innate drive of organisms to increasingly complexity causes evolutionary change. However, modern genetics has shown that acquired characteristics cannot be passed on.

The Darwinian Revolution
6. Darwin’s observations during his voyage on HMS Beagle led him to formulate and support his theory of evolution
- plants & animals in South America were very distinct from Europe’s
- Organisms from temperate regions of South America were more like others in the South American - tropics than others from Europe’s temperate regions – fossils displayed the same phenomenon
- earthquake caused coastline to rise
- fossils of ocean organisms high in Andes
- unusual organisms found near young volcanic islands of Galapagos
- most animal species on Galapagos are found nowhere else, yet they resemble species found on the - South American mainland
- 13 species of finches were found with clear beak differences
When he returned to Great Britain in 1836, Darwin began to link the origin of new species with adaptation of species to their environment. By the early 1840s, Darwin had developed his theory of natural selection as the driving force of evolution.

7. While traveling on the Beagle, Darwin read Lyell’s Principles of Geology, which included his idea of uniformitarianism. Darwin then witnessed and experienced an earthquake near Chile, which caused a rise in the coastline. Then, he discovered fossils of ocean organisms in the Andes—which made his infer that the rocks has been raised by similar geological processes. Darwin thus slowly accepted Lyell’s ideas and rejected the old view of gradualism.

8. Descent with modification means that all organisms are descendent of one comment ancestor in their remote past and thus are all related. This idea of Darwin’s suggests that over time, descendents of a common ancestor adapted different to their specific habitats in order to survive and reproduce.

9. Darwin’s voyage on the HMS Beagle convinced him that species change over time. He was able to see how the same species could have a variety of inheritable traits depending on their environment. Through his collective data and observations, Darwin noted how organisms are closed related and seem to share a line of descent, branching down from a common ancestor. Over time, Darwin drew the conclusion that organisms accumulated modifications or adaptations

10. Linnaeus’ classification system or taxonomic scheme fit with Darwin’s theory because it showed how certain organisms can resemble on another more than others do. Apply Darwinism, the hierarchy of this system shows how life branched out from descent from common ancestors.

11. Darwin’s 3 Inferences – led him to propose that the mechanism for evolutionary change was natural selection

FIRST: Because more individuals are produced in an environment than can be
supported, there is a struggle for existence among individuals of a
population. In the end, only a faction of offspring survive.
-Evidence: Due to the high potential fertility of all species, if all individuals born
reproduced successful, population sizes would increase exponentially, yet they
seem to remain stable... Environmental resources are limited.

SECOND: Inherited traits determine survival in the struggle for
existence. Individuals better suited to their environment will live
to reproduce and create more offspring than those less fit
individuals.
-Evidence: No two individuals of a population are
identical—characteristics vary, and this variation can be inherited.

THIRD: Over time, the unequal ability of individuals to survive and
reproduce changes the population. The favorable characteristics will
accumulate over generations.

12. Thomas Malthus’ essay in 1798 on the human population influenced Darwin’s beliefs of “overreproduction.” Malthus wrote that the majority of human problems (i.e. disease, war, homelessness) were caused by the fact that the population size increases faster than food and other resources do. Darwin saw that this potential could be applied to all organisms, yet only a small number of offspring in nature live to reproduce successfully.

13. Artificial selection is the breeding of certain individuals to produce a desired trait. Reproduction is not random, but instead directed. Over a relatively short period of time, changes can be seen in the domesticated organisms. Natural selection is the modification of a species over many thousands of generations through differential success in reproduction due to variable heritable traits passed down to offspring that interact with their environment.

14. Individuals organisms cannot evolve because the process is measured as changes in heritable traits over successive generations. Thus, populations are the smallest unit that can evolve.

15. Reznick and Endler’s hypothesized that differences in life-history traits between guppy populations were due to selective pressure based on predation. The experiments that supported their belief involved a study that lasted over a decade. In different pools in a river system, differences between guppy populations’ age and size of sexual maturity were observed, caused by the disparity of predators present. In the pools where the main predator was the killifish, which eats small guppies, the latter grows quickly and reaches maturity at a faster rate in order to reproduce. In the pools where the pike-cichlid was the major predator, the guppies grew at a slower rate and reproduced at a younger age, so as to avoid being eaten, since their predator mostly fed on large, adult guppies.
To test whether these differences are due to natural selection, Reznick and Endler introduced guppies from pike-cichlid locations to new pools that contained killifish but no guppies. 11 years later, the transplanted guppies were, on average, 14% heavier at maturity than the nontransplanted populations, and their average age at maturity had also increased.
Because pike-cichlids mainly feed on reproductively mature adults, the chance that a guppy will survive to reproduce several times is low. The guppies with the greatest reproductive success in these ponds are therefore those that mature at a young age and small size.

16. Darwin’s theory of natural selection and descent with modification help explain homologous structures, or one that are similar in different species due to common ancestry. Homologies represent variation on ancestral traits. Vestigial organs, another homologous structure, have little to no use in a living organism, but were once important in their ancestors. Examples of these include the appendix in humans. At the molecular level, the similarities in organisms due to relations can be seen in the genetic code.

17. The theory of evolution is supported by evidence from biogeography, or the geographical distribution of species. First of all, species are generally more closely related to other in the same general area than to other species (with similar ways of life) in different areas. Secondly, study of islands have shown that their plants and animals are endemic, or not found elsewhere in the world. A closer look, however, will show that the species found on the island resemble the nearest mainland more than other island groups.

18. Darwinism is not “just a theory” because it is supported by large amount of data, and its effects can be observed in nature. There is a sound scientific basis for Darwinism.
When used colloquially, “theory” means hypothesis or speculation. A simpler word could be “guess.” In science, “theories” are comprehensive attempts to explain a phenomena or event using a collection of data and observations. Scientific theories are not accepted until they have been tested and observed over time, as with natural selection, which has been investigated and checked continuously by scientists.

AP Biology Ch20 Objectives

Chapter 20 – DNA Technology and Genomics

*13, 16, 17 don't have the best answers ever, but my teacher always checked for completion so...

2. Restriction enzymes’ natural function is to cut DNA molecules at specific locations. In bacteria, these enzymes help cut foreign DNA, a process called restriction, and protect bacteria against phages and other bacteria. In recombinant DNA technology, they help cloning genes and DNA by cutting at specific location (thus genes can be reattached elsewhere)
3. Usefulness of Sticks Ends When Producing Recombinant DNA
Sticky ends, or single-stranded and staggered ends, can form hydrogen bonds with complementary sticks ends on any other DNA molecules cut with the same enzyme. They help the cut DNA reattach (generally elsewhere).

4. To clone a eukaryotic gene in a bacterial plasmid...
a. Isolate source of DNA and plasmid (cloning vector)
b. Insert DNA into plasmid
i. DNA and plasmid cut w/ same restriction enzyme
1. plasmid only cut at restriction site on lacZ gene (disabling function)
2. eukaryotic DNA cut in many location, including desired gene
ii. all fragments have complementary sticky ends
c. Mix DNA fragments together to start the base-pairing. Add DNA ligase to make bonds permanent.
d. Mix recombinant plasmids with bacteria lacZ-, which is unable to hydrolyze lactose.
e. Plate bacteria into solid nutrient medium with ampicillin and X-gal. Only the bacteria with ampR grow. X-gal is used to identify the bacteria that have foreign DNA.
f. Identified cells that were cloned with the right gene, using nucleic acid hybridization, a nucleic acid probe, or other methods

5. Nucleic acid hybridization can identify recombinant cells with the gene of interest by the base-pairing the gene and a complementary sequence. Another technique requires the use of a nucleic acid probe, which identifies cells through a radioactively labeled sequence of RNA or DNA.

8. Using yeast cells instead of bacteria as host has some advantages, including yeast’s capability of providing the posttranslational modifications that many proteins require. In addition, yeast already has the essentials of a eukaryotic chromosome.

10. The polymerase chain reaction (PCR) can amplify any piece of DNA without the use of cells. First, DNA is incubated in a test tube with special DNA polymerase, as well as a primer (short single-stranded DNA). PCR involves a three-step cycle: heating, cooling, and replicating. First, heating denatures the DNA. Then, cooling allows the primers to form hydrogen bonds to the denatured DNA. Next, the DNA polymerase extends the primers in a 5’ à 3 ‘ direction. PCR has the ability to make billions of copies in only a span of a few hours (faster than recombinant bacteria). However, a standard DNA polymerase can’t be use in PCR because it might be denatured during the heating process. Also, errors during replication limit the number of good copies that can be made when vast amounts of DNA are needed.

11. Gel electrophoresis separates nucleic acids by the rate of their movement through an electrically charged gel. The rate of movement depends on size, electrical charge, and other physical properties of macromolecules. Distinguishing between 2 alleles of a gene uses the same process.

12. Nucleic acid hybridization is a technique that depends on the base pairing of DNA. The gene of focus will theoretically bond with a complimentary strand, a different nucleic acid molecule (called the nucleic acid probe). It involves synthesizing RNA or DNA, radioactively labeling a probe, and tagging the colonies with the gene.

13. Southern blotting joins gel electrophoresis and nucleic acid hybridization. The electrophoresis will produce bands from the differences in physical properties. Then, nucleic acid hybridization will label certain bands using a specific radioactive probe. From there, the gene of interest can be found. The process shows whether or not a specific sequence is present in a DNA sample and the size of restriction fragments that holds the sequence. Restriction fragment length polymorphism (RFLP) can be used as a genetic marker for a particular location/locus in the genome (for making linkage maps). They are detected & analyzed by Southern blotting

15. The goal of the Human Genome Project is to discover the sequencing of the human genome using new DNA technology. A more detailed view of the human genome was desired, with genetic linkage maps, physical maps, as well as (the previously mentioned) DNA sequencing.

16. Cytogenetic maps based on karyotyping and fluorescence hybridization provided a basis for research. A linkage map was then made, with thousands of markers inter-spaced between the chromosomes. Recombination frequencies dictated the order and relative distance of markers. Genetic linkage was tested using those known markers. Then, distances were converted to numbers of nucleotides—a physical measure. A physical map involves cutting chromosomal DNA into identifiable restriction fragments and determining their order. DNA sequencing contributes to the genome mapping project...

17. J. Craig Venter and Celera Genomics used powerful computers assemble DNA sequence from random fragments, skipping the first two steps.

18. DNA sequences are collected in computer data banks. Then, special software scans DNA sequences to find signs of protein-coding, such as start/stop signal and RNA splicing areas.

19. The surprising result of the Human Genome Project is that the estimated number of human genes is 25,000 or fewer, one and a half as much as a fruit fly. One flowering plant has a genome 40 times the size of the human genome.

AP Biology Ch21 Objectives

Chapter 21 – The Genetic Basis of Development

From Single Cell to Multicellular Organism
1. Fruit fly (Drosophila melanogaster) – small, easily raised in labs, short generation time, numerous offspring, embryos develop outside of parents’ bodies
Nematode (Caenorhabditis elegans) –easy to grow in petri dish, small & simple body, few cell types, rapid development, mutations easily detected
Mouse (Mus musculus) – comparable genome to humans
Zebrafish (Danio Rerio) – small, easily bred, grow from transparent eggs, rapid early development
Common wall cress (Arabidopsis thaliana) – able to grow in test tube, produces many offspring, relatively small genome

2. Morphogenesis is the physical process in which an organism takes shape. Literally, it means “creation of form.” In plants, morphogenesis and growth related to overall size are not limited to juvenile periods, but continue throughout a plant’s lifetime. On the other hand, the same process in animals is specific to embryo development. Also, cell and tissue movement in required in animals to create the characteristic 3-D organism from the zygote.

Differential Gene Expression
3. Genomic equivalence, or the fact that almost all cells of an organism have the same genes, was proven by the experiment in which a differentiated cell was able to develop into a whole plant. This proved that one cell had all the information necessary to make all the other different types of cells. Cells in multicellular organisms differ due to gene expression—not genome makeup.

4. During differentiation, regulatory mechanisms turn specific genes on or off. However, as time goes by, the nucleus of differentiated cells changes in some way that prevents them from being totipotent; the chromatin structure alters (histones are chemically modified or DNA is methylated) while the DNA base sequence remains the same.

5. In the general process of mammal cloning, the first requirement is two individuals: one for cell donation and one for egg cell donation. The donated cells are half-starved in an inadequate nutrient medium, which thus stops the cell cycle and instigates dedifferentiation. Meanwhile, the donated egg cell has its nucleus removed. Then, the two cells are combined and fuse to form an early embryo which is implanted into a surrogate mother. The organism develops and is genetically identical to the cell donor (from the beginning of the process).

6. Stem cells are relatively unspecialized cells that are able to reproduce an infinite number of times. In the right conditions, they can also differentiate into various specialized cells. Embryonic stem cells are totipotent, while adult ones are pluripotent (not able to give rise to all cell types). In terms for medical significance, stem cells are being research for their possible use in repairing diseased or damaged organs.

7. Determination is a term biologist use in reference to the events that occur before visible cellular differentiation; the molecular changes that irreversibly commit a cell to its fate and function. Gene expression of tissue specific proteins marks cell determination and the change to differentiation. These proteins are cell-type-specific and give a cell its characteristic structure for its future function. Differentiated cells specialized in making their tissue-specific proteins.

9. Regulation of gene expression can be due to change in chromatin, for example the methylation of DNA, or the acetylation of histones. However, the instructions given to a cell telling it when to express certain genes come from two main sources. The first are cytoplasmic determinants. Being heterogeneous, an egg cell’s cytoplasm contains unevenly distributed mRNA, protein, organelles, etc. When mitotic divisions early on cause the zygote’s cytoplasm to be divided into different cells, different nuclei become exposed to different determinants. These determinants in turn regulate gene expression during cell differentiation. Secondly, the cell’s environment is a factor in gene expression. Contact with other surfaces/cells, or nearby signals may affect the time or way in which a cell differentiates.

Genetic and Cellular Mechanisms of Pattern Formation
10. Drosophila were used to investigate basic aspects of pattern formation (i.e. segmentation and axis formation), which is the development of the spatial organization of tissues and organs in an organism. The research of this species has established the fact that development is controlled by genes, and has led to the understanding that certain molecules play key roles in these processes.
In the investigation, first, mutants were examined, and their genetic maps were studied to find out what went wrong. Then, two German researchers decided to identify all the genes affecting segment formation, and the genes of the mother (due to cytoplasmic determinants).
The two men searched for recessive mutation (which could be propagated in heterozygotes), and then exposed flies to mutagenic chemicals to create gamete mutations. The flies’ offspring were then examined for abnormal segmentation in dead embryos.

11. Maternal effect genes can cause mutations in offspring. A mutant mother will pass the phenotype on to her progeny without regard to the genotype. This occurs because protein products of maternal effect genes are inserted into the egg (when it is still inside the mother). Mothers with a mutated gene make defective gene products or do not make a gene product at all, both of which result in abnormal development. Maternal effect genes also control orientation/polarity of the egg by setting up the anterior-posterior axis as well as the ventral-dorsal one. The bicoid genes of the mothers set up the front end of the flies. Morphogens establish axes.

AP Biology Plant Notes (Ch 20-30 something)

Seed Vascular Plants

P = plant
A = animal
gp = gametophyte
SP = seed plant


Reproductive adaptations
1. gametophytes of seed plants become more reduced in size (compared to the seedless vascular plants) and are retained within moist reproductive tissue of the sporophyte, unlike seedless plant gametophytes, which are independent
2. seeds replace spores as main means of dispersing offspring
a. harsh terrestrial environment required resistant structure for dispersal
b. bryophytes and seed(less?) vascular plants release hard spores
c. seed = more hardy due to multicellularity
d. seed contains sporophyte embryo, food supply, surrounding protective coat
e. all seed plants = heterosporous (have mega and micro sporangia)
f. seed develops into megasporangia
3. pollen became vehicle for sperm cells in seedplants
a. microspores due to pollen grains which mature to male gametophyte
b. coated w/ polymer sporopollenin
c. carried by wind/animals following release

GYMNOSPERMS = lack enclosed chambers (ovaries) in which seeds develop -> open seed

needle-shaped leaves = adapted to dry conditions
v thick cuticle
v stomata are in pits reducing water loss
v despite its different shape, it has megaphylls like all SP leaves

LIFE CYCLE OF A PINE
v sporophyte dominate
v sporangia located on cones
v multicellular sporophyte reduced, develops from haploid spores retained in sporangia
v male gametophyte consists of multicell nutritious tissue
v archegonium developes w/in ovule
v heterosporoustakes nearly 3 yrs to complete life cycle

AP Biology Ch28 Notes

PROTISTS

almost all = aerobic... use mitochondria for respiration
most have cilia and/or flagella (convergent evolution, not homologous to prokaryotes)

Candidate Kingdoms w/ Characteristics
- Diplomonadida – 2 equal sized nuclei
- Parabasala – undulating membrane
- Euglenozoa – spiral/crystalline rod in flagella
- Alveolata – alveoli under plasma membrane
- Stramenopila – hairy and smooth flagella
- Cercozoa & Radiolaria – amoebas w/ threadlike pseudopodia
- Amoebozoa – amoebas w/ lobe-shaped pseudopodia
- Rhodophyta – red algae, phycoerythrin (pigment), not flagellated
- Chlorophyta – group of green algae, plant-type chlorophyll

Endosymbiosis – Genesis – 1st Eukaryotes from Prokaryotes
- natural selection driving prokaryotic evolution towards greater complexity

o multicellular forms (cyanobacteria)
o complex prokaryotic communities
o compartmentalization of different functions w/in single cell
o specialization of membrane invaginations (mesosomes) -> golgi, ER?

- SEQUENTIAL
- primary

o photosynthetic cyanobacteria -> plastids -> red & green algae
o close resemblance btwn cyanobacteria & algae

- secondary - heterotrophic eukaryote engulfed in food vacuole à endosymbiont à organelle
- structures/processes

o cytoskeleton
o membrane bound nucleus
o mitochondria
o chloroplasts
o life cycles -> (a)sexual reproduction, meiosis (4 haploid gametes), mitosis (2 cell division)
o endomembrane system
o 9 + 2 flagella
o multiple linear chromosomes w/ proteins

- SERIAL
- certain prokaryotic species (endosymbionts lives) w/in larger prokaryotes...
- evidence based upon mitochondria & chloroplasts’ similarity to prokaryotes in...

o size
o inner membrane w/ enzymes
o replication through binary fission
o circular DNA w/ lack of histones
o own RNA and ribosomes

alternation of generations

MALARIA LIFE CYCLE
parasite plasmodium continually changes surface proteins à protects it from immune system
- inside of mosquito = sexual reproduction

o pick up gametocytes from ppl -> becomes gametes
o fertilization (diploid ONLY here), meiosis -> sporozoites

- goes to human = asexual reproduction (haploid)

o mostly found in liver & blood cells
o fill cells with waste, causing them to explode

Variable Life Cycles
- mitotic divisions
- asexual reproduction
- sexual reproduction -> syngamy: fusion 2 cells, trade genes (btwn episodes of asexual reproduction)
- conjugation

o two individuals exchange haploid micronuclei, sexual shuffling of genes occurs
o dynamics + advantages of sex w/o male or female genders
o eliminates transposons
o increases genetic variation -> natural selection à greater reproductive success

Ecological Categories
- photosynthetic = plant-like (algae)
- ingestive = animal-like (protozoans)
- absorptive = fungi-like
Nutritional Categories
- photoautotrophic have chloroplasts
- heterotrophic absorb/ingest food
- mixotrophic do both

Euglena
- bridge evolutionary gap btwn animals & plants à characteristics from both groups
- may carry on photosynthesis
- have flagella & contractile vacuoles
- lack cell wall
- unicellular
- disc-shaped mitochondrial cristae?
- obtain energy how?
RED Algae
- adapted to deep water – photosynthetic pigments efficient at absorbing blue/green light
- characterized by alternation of generations
- agar, algin, carrageenan
- alveoli under plasma membrane
GREEN Algae - most closely related to plants
Dinoflagellates
- “blooms” = population explosion à red tide caused by carotenoids
- produce nerve agent toxic to ppl
Diatoms = special cell wall structure can support elephant’s weight

phototactic = able to sense light and swim towards it, prefer photosynthesis
phytoplankton = basis of food chain
cyst formation is like that of endospore in bacteria... allows for survival in extremes
protozoans generally heterotrophic, animal-like, ingestiveoomycetes once categorized as fungi