Chapter 34-The Nervous System

1.acetylcholine Neurotransmitter; acts on brain, spinal cord, glands, and muscles.
2.action potential Abrupt, brief reversal in the resting membrane potential of excitable cells.
3.autonomic nerve One of the nerves from central nervous system to smooth muscle, cardiac muscle, and glands of viscera.
4.axon Neuron's signal-conducting zone.
5.blood-brain barrier Mechanism that controls which solutes enter cerebrospinal fluid.
6.brain Of most nervous systems, integrating center that receives and processes sensory input and issues coordinated commands for responses by muscles and glands.
7.brain stem Most ancient nerve tissue in the vertebrate hindbrain, midbrain, and forebrain.
8.central nervous system Brain and spinal cord.
9.cerebellum Hindbrain region with reflex centers for maintaining posture and smoothing out limb movements.
10.cerebral cortex Thin surface layer of cerebral hemispheres; receives, integrates, and stores sensory information; coordinates responses.

11.cerebrum Forebrain region that generally deals with olfactory input and motor responses. In mammals, it evolved into the most complex integrating center.
12.chemical synapse Thin cleft between a presynaptic neuron and a postsynaptic cell. Neurotransmitter molecules diffuse across it.
13.dendrite Short, slender extension from cell body of a neuron; commonly a signal input zone.
14.drug addiction Dependence on a drug, which assumes an ''essential'' biochemical role in the body following habituation and tolerance.

15.hypothalamus Forebrain center of homeostatic control over the internal environment influences hunger, thirst, sex, other viscera-related behaviors, and emotions.
16.interneuron Neuron of brain or spinal cord.
17.limbic system In cerebral hemisphere, centers that govern emotions; has roles in memory.
18.medulla oblongata Hindbrain region with reflex centers for basic tasks; coordinates motor responses with complex reflexes; influences sleeping.
19.memory The capacity to store and retrieve information about past sensory experience.
20.motor neuron Neuron that relays signals from brain or spinal cord to muscle or gland cells.
21.nerve Sheathed, cordlike bundle of the axons of sensory neurons, motor neurons, or both.
22.nerve net Simple nervous system in epidermis of cnidarians and some other invertebrates; a diffuse mesh of simple, branching nerve cells interacts with contractile and sensory cells.
23.nervous system Integrative organ system with nerve cells interacting in signal-conducting and information-processing pathways. Detects and processes stimuli, and elicits responses from effectors.
24.neural tube The embryonic and evolutionary forerunner of brain and spinal cord.
25.neurotransmitter Any of a class of signaling molecules secreted by neurons. It acts on cells next to it, then is rapidly degraded or recycled.
26.parasympathetic nerve An autonomic nerve. Its signals slow down overall activities and divert energy to basic tasks; they also help make small adjustments in internal organ activity by acting continually in opposition to sympathetic nerve signals.
27.peripheral nervous system All nerves leading into and out from the spinal cord and brain. Includes ganglia of those nerves.
28.pons A hindbrain traffic center for signals between cerebellum and forebrain centers.
29.positive feedback mechanism Homeostatic control; it initiates a chain of events that intensify change from an original condition, then intensification reverses the change.
30.reflex Stereotyped, simple movement in response to stimuli. In the simplest reflex arcs, it results from sensory neurons synapsing directly on motor neurons.
31.resting membrane potential Of a neuron and other excitable cells, a voltage difference across the plasma membrane that holds steady in the absence of outside stimulation.
32.reticular formation A mesh of interneurons extending from the upper spinal cord, through the brain stem, and into the cerebral cortex; it is a low-level pathway of information flow.
33.sensory neuron Type of neuron that detects a stimulus and relays information about it toward an integrating center.
34.sodium-potassium pump Type of membrane transport protein that, when activated by ATP, selectively transports potassium ions across a membrane against its concentration gradient, and passively allows sodium ions to cross in the opposite direction.
35.somatic nerve Nerve leading from a central nervous system to skeletal muscles.
36.spinal cord Part of central nervous system, in a canal inside the vertebral column; site of direct reflex connections between sensory and motor neurons; has tracts to and from the brain.
37.stimulus A specific form of energy that activates a sensory receptor able to detect it.
38.sympathetic nerve An autonomic nerve; deals mainly with increasing overall body activities at times of heightened awareness, excitement, or danger; works continually in opposition with parasympathetic nerves to make minor adjustments in internal organ activities.
39.synaptic integration Moment-by-moment combining of all excitatory and inhibitory signals arriving at the trigger zone of a neuron or some other excitable cell.
40.thalamus A forebrain region that is a coordinating center for sensory input and a relay station for signals to the cerebrum.

Vocabulary Chapter 33

1.adhering junction Junction where a mass of anchored proteins help adjoining cells adhere.
2.adipose tissue A connective tissue having an abundance of fat-storing cells.
3.blood Fluid connective tissue of water, solutes, and formed elements. Transports substances to and from cells, helps maintain internal environment.

4.bone tissue Of vertebrate skeleton, a tissue of osteoblast secretions hardened with minerals.
5.cardiac muscle tissue A contractile tissue that is present only in the heart wall.
6.cartilage Connective tissue with solid, pliable intercellular material that resists compression.

7.dense, irregular connective tissue Animal tissue with fibroblasts, many asymmetrically positioned fibers in ground substance. In skin and some capsules around organs.
8.dense, regular connective tissue Animal tissue with rows of fibroblasts between parallel bundles of fibers. In tendons, elastic ligaments.
9.ectoderm The first-formed, outermost primary tissue layer of animal embryos; gives rise to nervous system tissues and integument's outer layer.
10.endocrine gland Ductless gland that secretes hormones, which the bloodstream distributes.

11.endoderm Inner primary tissue layer of animal embryos; source of inner gut lining and derived organs.
12.epithelium Animal tissue that covers external surfaces and lines internal cavities and tubes. One surface is free and the other rests on a basement membrane.

13.exocrine gland Glandular structure that secretes products, usually through ducts or tubes, to a free epithelial surface.
14.gap junction Cylindrical arrays of proteins in the plasma membrane that pair up as open channels for signals between adjoining cells.
15.gland cell A cell that secretes products unrelated to their own metabolism for use elsewhere
16.homeostasis State in which physical and chemical aspects of internal environment (blood, interstitial fluid) are being maintained within ranges suitable for cell activities.
17.internal environment Blood + interstitial fluid.
18.loose connective tissue Animal tissue with fibers, fibroblasts loosely arrayed in semifluid ground substance.
19.mesoderm Primary tissue layer of all large, complex animals; gives rise to many internal organs and part of the integument.
20.nervous tissue Connective tissue composed of neurons and often neuroglia.

21.neuroglia Collectively, cells that structurally and metabolically support neurons. They make up about half the volume of nervous tissue in vertebrates.
22.neuron Type of nerve cell; basic communication unit in most nervous systems.
23.organ Body structure with definite form and function that consists of more than one tissue.
24.organ system Organs interacting chemically, physically, or both in a common task.
25.skeletal muscle tissue Striated contractile tissue that is the functional partner of bone.
26.smooth muscle tissue Nonstriated contractile tissue found in soft internal organs.
27.tight junction Cell junction where strands of fibrous proteins oriented in parallel with a tissue's free surface collectively block leaks between the adjoining cells.
28.tissue Of multicelled organisms, a group of cells and intercellular substances that function together in one or more specialized tasks.

Vocabulary Chapter 20

1. angiosperm: Flowering plant.
2. archaebacterium: Member of the prokaryotic domain Archaebacteria
3. Archean eon: Eon in which life arose (3.8-2.5 bya).
4. big bang: Model for origin of universe.
5. Cenozoic era: The present era (65 mya to present).
6. crust, of Earth: Outer zone of low-density rocks resting on the Earth's mantle.

7. dinosaur: One of a fabulous group of reptiles that originated in the Triassic and became the dominant land vertebrates for 125 million years.
8. Ediacaran: One of the species with a highly flattened body that arose in the precambrian.
9. endosymbiosis theory:Continuing physical contact between two species, one of which lives and reproduces inside the other's body.
10. eubacterium: Prokaryotic cell; has a nucleoid, but no nucleus, cytoplasm, or cell membrane; most have a cell wall, some encapsulated.

11. eukaryotic cell: Cell having a nucleus and other membrane-bound organelles.
12. global broiling hypothesis: Theory that an asteroid impact caused the K-T mass extinction by creating a colossal fireball, the debris from which raised global air temperature by thousands of degrees.
13. gymnosperm: Type of vascular plant in which seeds form on exposed surfaces of reproductive structures (e.g., on cone scales).

14. K-T asteroid impact theory: A huge asteroid hit Earth at the K-T boundary; last dinosaurs perished during the mass extinction.
15. mantle: Of mollusks, a tissue draped over the visceral mass. Of Earth, a zone of intermediatedensity rocks beneath the crust.
16. Mesozoic era: An era (240-65 mya) of spectacular expansion in the range of global diversity.

17. Paleozoic era: Era from Cambrian, Ordovician, Silurian, Devonian, Carboniferous, through the Permian (544 to 248 mya).
18. prokaryotic cell: Archaebacterium or eubacterium; single-celled organism, most often walled; lacks the profusion of membranebound organelles observed in eukaryotic cells.
19. Proterozoic eon: Period from 2.5 billion to 570 million years ago; period during which eukaryotic cells arose.
20. protistan: Photoautotroph or heterotroph (or both) unlike bacteria; some like earliest eukaryotic cells. Has a nucleus, larger ribosomes, mitochondria, ER, Golgi bodies, chromosomes with numerous proteins, and cytoskeletal microtubules. Range in size from microscopic algae to giant kelps.
21. proto-cell: Hypothetic cell-like stage between chemical evolution and the first living cell.
22. RNA world: One model for prebiotic evolution in which RNA was the template for protein synthesis before the evolution of DNA.
23. stromatolite: Fossilized mats of shallow-water microbial communities, mainly cyanobacteria, from Archean to precambrian. Cell secretions blocked UV radiation but trapped sediments, and new mats grew on old ones; some are half a mile thick and hundreds of miles across.

Vocabulary chaperts 17,18 and 19 :D

1.analogous structure Body parts that once differed in evolutionarily distant lineages but converged in structure and function as responses to similar environmental pressures.
2.asteroid Rocky, metallic body, a few to 1,000 kilometers across, hurtling through space.
3.comparative morphology Scientific study of comparable body parts of adults or embryonic stages of major lineages.
4.derived trait A novel feature that evolved but once and is shared only by the descendants of the ancestral species in which it evolved.
5.fossil Recognizable, physical evidence of an organism that lived in the distant past.
6.fossilization How fossils form.

7.geologic time scale Time scale for the Earth's history with major subdivisions corresponding to mass extinctions.
8.Gondwana Paleozoic supercontinent; with other land masses, it formed Pangea.
9.half-life The time it takes for half of a given quantity of any radioisotope to decay into a different, and less unstable, daughter isotope.
10.homologous structure Of separate lineages, comparable body parts that show underlying similarity even when they may differ in size, shape, or function; outcome of morphological divergence from a shared ancestor.
11.lineage Line of descent.
12.morphological convergence evolutionarily distant lineages evolve in similar ways and end up being alike in appearance, functions, or both.

13.morphological divergence Macroevolutionary pattern; genetically diverging lineages undergo change from body form of a common ancestor.
14.Pangea Paleozoic supercontinent upon which the first terrestrial plants and animals evolved.
15.plate tectonics theory Theory that great slabs of the Earth's outer layer float on a hot, plastic mantle. All plates are slowly moving and have rafted continents to new positions over time.

16.stratification Stacked layers of sedimentary rock, built up by gradual deposition of volcanic ash, silt, and other materials over time.
17.theory of uniformity Early theory that the earth's surface changes in gradual, uniformly repetitive ways. Has since been replaced by plate tectonics theory.
18.adaptive radiation Macroevolutionary pattern; burst of genetic divergences from a lineage that gives rise to many species, each using a novel resource or a new habitat.
19.adaptive zone Minimum amount of energy required to get a specific reaction going, with or without the help of an enzyme. Reactions differ in the amount required.

20.allopatric speciation A physical barrier arises, separates populations or subpopulations of a species, ends gene flow, and favors divergences that end in speciation.

21.anagenesis changes in allele frequencies and morphology accumulate within an unbranched line of descent.

22.archipelago Island chain some distance away from a continent.


23.biological species concept Defines a species as one or more populations of individuals that are interbreeding under natural conditions, producing fertile offspring, and are isolated reproductively from other such populations.

24.cladogenesis Speciation pattern in which a lineage splits and isolated populations undergo genetic divergence.

25.dosage compensation Any mechanism that balances gene expression between the sexes during critical early stages of development.

26.evolutionary tree a branch point means divergence from a shared ancestor and branches signify separate lines of descent.


27.extinction Irrevocable loss of a species.

28.gene flow alleles enter and leave a population as an outcome of immigration and emigration, respectively.

29.genetic divergence Gradual accumulation of differences in gene pools of populations or subpopulations of a species after a geographic barrier arises and separates them.

30.gradual model of speciation Idea that species arise by many small morphological changes that accumulate over great spans of time.


31.hybrid zone Where adjoining populations are interbreeding and producing hybrid offspring.

32. mass extinction Catastrophic event or phase in geologic time when entire families or other major groups are irrevocably lost.

33. parapatric speciation Idea that neighboring populations can become distinct species while maintaining contact along a common border.

34.punctuation model of speciation Idea that most morphological changes occur in a brief span when populations start to diverge; speciation is rapid, and the daughter species change little for the next 2-6 million years or so.

35.reproductive isolating mechanism Heritable feature of body form, functioning, or behavior that prevents interbreeding between two or more genetically divergent populations.

36.speciation The formation of a daughter species from a population or subpopulation of a parent species by way of microevolutionary processes.
37.species Of sexually reproducing organisms, one or more natural populations in which individuals are interbreeding and are reproductively isolated from other such groups.

38.sympatric speciation A speciation event within the home range of an existing species, in the absence of a physical barrier.

Vocabulary chapter 17

allele: One of two or more molecular forms of a gene that arise by mutation and code for different versions of the same trait.

allele frequency: For a given gene locus, the relative abundances of each kind of allele among all the individuals of a population.

antibiotic: Metabolic product of soil microbes that kills bacterial competitors for nutrients.

balanced polymorphism: Form of selection in which two or more alleles for a trait are being maintained in a population over time.

biogeography: Scientific study of the world distribution of species.

bottleneck: Severe reduction in the size of a population, brought about by intense selection pressure or a natural calamity.

catastrophism: Idea that abrupt changes in the geologic or fossil record were divinely invoked.

comparative morphology: Scientific study of comparable body parts of adults or embryonic stages of major lineages.

directional selection: Mode of natural selection by which allele frequencies underlying a range of

phenotypic variation: shift in a consistent direction, in response to directional change or to new conditions in the environment.

disruptive selection: Mode of natural selection by which the different forms of a trait at both ends of the range of variation are favored and intermediate forms are selected against.

evolution: Genetic change in a line of descent. Outcome of microevolutionary events: gene mutation, natural selection, genetic drift, and gene flow.

fitness: Increase in adaptation to environment as brought about by genetic change.

fixation: Loss of all but one kind of allele at a gene locus for all individuals in a population.

fossil: Recognizable, physical evidence of an organism that lived in the distant past.

founder effect: A form of bottlenecking. By chance alone, a few individuals that establish a new population have allele frequencies that differ from those of the original population.

gene flow: Microevolutionary process; alleles enter and leave a population as an outcome of immigration and emigration, respectively.

gene pool: All genotypes in a population.

genetic drift: Change in allele frequencies over the generations due to chance alone. Its effect is most pronounced in very small populations.

genetic equilibrium: In theory, a state in which a population is not evolving. Compare Hardy-Weinberg rule.

Hardy-Weinberg rule Allele: frequencies stay the same over the generations when there is no mutation, the population is infinitely large and isolated from other populations of the species, mating is random, and all individuals are reproducing equally and randomly.

inbreeding: Nonrandom mating among close relatives that share many identical alleles.
lethal mutation Mutation with drastic effects on phenotype; usually causes death.

microevolution: Of a population, any change in allele frequencies resulting from mutation, genetic drift, gene flow, natural selection, or some combination of these.

mutation rate: Of a gene locus, the probability that a spontaneous mutation will occur during or between DNA replication cycle.

natural selection: Microevolutionary process; the outcome of differences in survival and reproduction among individuals that differ in details of heritable traits.

neutral mutation: A mutation with little or no effect on phenotype, so natural selection can't change its frequency in a population.

polymorphism: The persistence of two or more qualitatively different forms of a trait (morphs) in a population.

population: All individuals of the same species that are occupying a specified area.

sampling error: Use of a sample or subset of a population, an event, or some other aspect of nature for an experimental group that is not large enough to be representative of the whole.

sexual selection: A microevolutionary process; a type of selection that favors a trait giving an individual a competitive edge in attracting or keeping a mate. stabilizing selection: Mode of natural selection by which intermediate phenotypes in the range of variation are favored and extremes at both ends are eliminated.

theory of uniformity: Early theory that the earth's surface changes in gradual, uniformly repetitive ways. Has since been replaced by plate tectonics theory.

DNA...Chapters 13 & 14!!

1.adenine:A purine; a nitrogen-containing base in certain nucleotides. Base pairs with thymine in DNA.
2.cytosine:Pyrimidine; one of the nitrogen-containing bases in nucleotides.
3.guanine:Nitrogen-containing base in one of four nucleotide monomers of DNA or RNA.
4.thymine:A nitrogen-containing base; one of the nucleotides in DNA.




5.bacteriophage:Category of viruses that infect bacterial cells.
6.cloning:Making a genetically identical copy of DNA or of an organism.
7.deoxyribonucleic acid:Of cells and many viruses, the molecule of inheritance. H bonds join its two helically twisted nucleotide strands, one of which has instructions for synthesizing all of the enzymes and other proteins required to build and maintain cells.

8.DNA ligase:Enzyme that seals new base-pairings during DNA replication.
9.DNA polymerase:Enzyme of replication and repair that assembles a new strand of DNA on a parent DNA template.
10.DNA repair:Enzyme-mediated process that fixes small-scale alterations in a DNA strand by restoring the original base sequence.
11.DNA replication:Any process by which a cell duplicates its DNA molecules before dividing.
12.nucleotide:Small organic compound with deoxyribose, a nitrogenous base, and a phosphate group. Monomer for adenosine phosphates, nucleotide coenzymes, and nucleic acids.
13.x-ray diffraction image:Pattern that forms on film exposed to x-rays that have been directed at a molecule; reveals positions of atoms, not the molecular structure.
14.anticodon:Series of three nucleotide bases in tRNA; can base-pair with an mRNA codon.
15.base sequence:Sequential order of bases in a DNA or RNA strand.
16.base-pair substitution:One amino acid has replaced another during protein synthesis.
17.carcinogen:Any substance or agent that can trigger cancer.
18.codon:One of 64 possible base triplets in an mRNA strand. A code word for an amino acid in a polypeptide chain; a few codons also act as START or STOP signals for translation.
19.deletion:At cytological level, loss of a segment from a chromosome. At molecular level, loss of one to a few base pairs from a DNA molecule.
20.exon:One of the base sequences of an mRNA transcript that will become translated.
21.gene mutation: A small-scale change in the nucleotide sequence of a DNA molecule.
22.genetic code:The correspondence between nucleotide triplets in DNA and specific sequences of amino acids in a polypeptide chain; the basic language of protein synthesis in cells.
23.insertion:Insertion of one to a few bases into a DNA strand. Also, a movable attachment of muscle to bone.
24.intron:A noncoding portion of a pre-mRNA transcript; excised before translation.
25.ionizing radiation:High-energy wavelengths.
26.RNA:A single strand of ribonucleotides transcribed from DNA, then translated into a polypeptide chain. The only RNA encoding protein-building instructions.
27.mutation rate:Of a gene locus, the probability that a spontaneous mutation will occur during or between DNA replication cycles

Human Genetics!!

1.abortion:Premature, spontaneous or induced expulsion of the embryo or fetus from uterus.

2.aneuploidy: Having one extra or one less chromosome relative to the parental chromosome number.

3.autosome: Any chromosome of a type that is the same in males and females of the species.



4.crossing over: At prophase I of meiosis, an interaction in which non-sister chromatids of a pair of homologous chromosomes break at corresponding sites and exchange segments; genetic recombination is the result.

5.deletion: At cytological level, loss of a segment from a chromosome. At molecular level, loss of one to a few base pairs from a DNA molecule.

6.disease: Outcome of infection when defenses aren't mobilized fast enough and a pathogen's activities interfere with normal body functions.

7.double-blind: study Different investigators independently collect, then compare data.


8.duplication: Gene sequence repeated several to many hundreds or thousands of times. Even normal chromosomes have such sequences.

9.genetic abnormality: A rare or less common version of a heritable trait.

10.genetic disorder: Any inherited condition that causes mild to severe medical problems.


11.genetic recombination: Result of any process that puts new genetic information into a DNA molecule (e.g., by crossing over).

12.homologous chromosome: Of cells with a diploid chromosome number, one of a pair of chromosomes identical in size, shape, and gene sequence, and that interact at meiosis. Nonidentical sex chromosomes (e.g., X and Y) also interact as homologues during meiosis.


13.in-vitro fertilization: Conception outside the body (''in glass'' petri dishes or test tubes).

14.independent assortment: Mendelian theory that by the end of meiosis, each pair of homologous chromosomes (and linked genes on each one) are sorted before shipment to gametes independently of how the other pairs were sorted. Later modified to account for the disruptive effect of crossing over on linkages.


15.inversion: Part of a chromosome that became oriented in reverse, with no molecular loss.

16.karyotype: Preparation of metaphase chromosomes sorted by length, centromere location, other defining features.

17.linkage group: All genes on a chromosome.

18.mosaicism: Cells of same type express genes differently, so phenotypic differences emerge in same type of tissue. E.g., occurs by X chromosome inactivation in female mammals; also by nondisjunction in any cell after fertilization (only descendants of altered cell inherit the abnormal chromosome number).


19.Non-disjunction: Failure of sister chromatids or a pair of homologous chromosomes to separate during meiosis or mitosis. Daughter cells end up with too many or too few chromosomes.

20.polyploidy: Having three or more of each type of chromosome in the nucleus of a eukaryotic cell at interphase.


21.reciprocal cross: A paired cross. In the first cross, one parent displays the trait of interest. In the second, the other parent displays it.

22.sex chromosome :A chromosome with genes that affect sexual traits. Depending on the species, somatic cells have one or two sex chromosomes of the same or different type (e.g., in mammals, XX females, XY males).


23.syndrome: A set of symptoms that may not individually be a telling clue but collectively characterize a genetic disorder or disease.
translocation Of cells, movement of a stretch of DNA to a new chromosomal location with no molecular loss. Of vascular plants, distribution of organic compounds by way of phloem.


24.X chromosome: A type of sex chromosome. An XX mammalian embryo becomes female; an XY pairing causes it to develop into a male.

25.Y chromosome: A type of sex chromosome. An XX mammalian embryo becomes female; an XY pairing causes it to develop into a male.