Introductory Biology I: Vocabulary Chapters 12 to 16 PDF

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Chapter 12 Vocabulary...

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Chapter 12 Vocabulary Cell Division – Reproduction of Cells (duh) Cell Cycle - Sequence of events in life of a cell in division in two. Composed of Interphase (G1, S, and G2) and M Phase (mitosis and cytokinesis) Genome – Genetic material of organism or virus Chromosomes – Cellular DNA and protein structure that just exists as a mass of DNA Chromatin – Complex of DNA and proteins that compose a eukaryotic chromosomes. When not dividing, it exists in long fibers that are uncondensed. Somatic Cells - All body cells except for the reproductive cells Gametes Reproductive cells that only have one set of chromosomes Sister Chromatids- Joined copies of the original chromosome. Each contain identical DNA Centromere- A region of chromosomal DNA where the chromatid is att MitosisThe division of genetic material in the nucleus and is usually followed immediately by cytokinesis. Cytokinesis- The division of the cytoplasm Mitotic (M) Phase- The phase that includes both mitosis and cytokinesis (shortest part of cell cycle). Alternates with Interphase Interphase- Longest state that accounts for 90% of the cycle and is divided into subphases. G1 Phase- First gap of cell cycle where the cell grows G2 Phase- 2nd gap where it grows more and it prepares for cell division. S Phase Part where the cell has been growing and it begins to copy its chromosomes Prophase- 1st state of Mitosis where chromatin condenses into chromosomes visible with a microscope. Mitotic spindle begins to form and the nucleolus disappears but the nucleus remains intact. Prometaphase - 2nd stage of Mitosis where the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes. Metaphase- 3rd state of mitosis where the spindle is complete and the chromosomes, attached to these tubes, are all aligned at the metaphase plate. Anaphase- 4th state of Mitosis where the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell. Telophase- 5th and last stage of mitosis where daughter nuclei are forming and cytokinesis has begun. Mitotic Spindle – Microtubules and associated proteins that is involved in movement of chromosomes during mitosis. Centrosome –Subcellular region containing material that functions throughout the cell cycle to organize the cell’s microtubules. AsterRadial array of short microtubules that extend from each centrosome. Kinetochore - Structure made up of proteins that have assembled on specific sections of DNA at each centromere. Metaphase Plate-Imaginary plane that is midway between the spindle’s two poles where the chromosomes meet in the middle during metaphase. CleavageProcess of cytokinesis in animal cells that is characterized by pinching of the plasma membrane. Cleavage Furrow- 1st sign of cleavage in animal cell; shallow groove around the cell in the cell surface. Cell Plate- A membrane-bounded, flattened sac located at the midline of a dividing plant cell, insinde which the new cell wall forms during cytokinesis Binary Fission – Refers to the process that Prokaryotes can undergo as a type of reproduction.

Origin of Replication- Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides. Cell Cycle Control System – a cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle. Checkpoint – Control point in the cell cycle where stop and go-ahead signals can regulate the cycle. 3 important checkpoints are found in G1, G2, and M phases Cyclin – A protein that gets its name from cyclically fluctuating concentration in the cell. Cyclin-Dependent Kinases (Cdks) - A protein kinase that is active only when attached to a particular cyclin. Maturattion-promoting Factor (MPF) – The cyclin-Cdk complex that was discovered first (from frog eggs). A protein complex required for a cell to progress from late interphase to mitosis. G0 Phase – Non dividing state occupied by cells that left the cell cycle, sometimes reversibly Growth Factor – A protein released by certain cells that stimulates other cells to divide. Density-dependent inhibition – A phenomenon in which crowded cells stop dividing. Anchorage dependence – To divide, they must be attached to a substratum such as the inside of a culture flask or the extra-cellular matrix of a tissue. Transformation – The process that causes them to behave like cancer cells. Benign Tumor – Mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable of surviging at a new site and generally remain at the site of the tumor’s origin. Malignant Tumor – A cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites. Malignant tumors can impair the functions of one or more organs. Metastasis – The spread of cancer to locations distant from their original site.

Chapter 13 Vocabulary Hereditary – Transmission of traits from one generation to the next Variation –Differences between members of the same species Genetics – scientific study of heredity and hereditary variation Genes – coded information in the form of hereditary units known as this Gametes – vehicles that transmit genes from one generation to the next (1/2 # of chromosomes) Somatic Cells – all cells of the body except for gametes Locus – gene’s specific location along the length of the chromosome Asexual reproduction – single individual is sole parent and passes copies of all its genes to offspring Clone – group of genetically identical individual Sexual Reproduction – two parents give rise to offspring that have unique combinations of both genes Life Cycle – generation-to-generation sequence of stages in reproductive history of an organism Karyotype – A display of the chromosome pairs of a cell arranged by size and shape Homologous Chromosomes (Homologs)- A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One chromosome is inherited from the organism’s father and the other from the mother. Also called homologous pair. Sex chromosomes – A chromosome responsible for determining gender Autosomes – A chromosome that is not directly involved in determining gender Diploid Cell – A cell containing two sets of chromosomes (2n), one inherited from each parent For humans, its 2n=46, meaning we have 23 pairs of chromosomes from each parent. Haploid cells – Gametes that contain only a single set of chromosomes (n=23) Fertilization – Fusion of a gametes’ nuclei Zygote – The diploid cell produced by the union of haploid gametes during fertilization; a fertilized egg Meiosis – A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell Alternation of Generations – A life cycle in which there is both a multicellular diploid for, the sporophyte, and a multicellular haploid form, the gametophyte Meiosis I – The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell Meiosis II – the 2nd division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell Crossing Over – the reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis Chiasmata – The x-shaped, microscopically visible region where crossing over has occurred earlier in prophase I between homologous nonsister chromatids. Chiasmata become visible after synapsis ends, with the two homologs remaining associated due to sister chromatid cohesion Synaptonemal Complex – A zipper-like structure composed of proteins, which connects two homologous chromsomes tightly along their lengths Synapsis – the pairing and physical connection of duplicated homologous chromosomes during prophase I of meiosis Recombinant Chromosomes – A chromosome created when crossing over combines DNA from two parents into a single chromosome

Chapter 14 Vocabulary Character – An observable heritable feature that may vary among individuals Trait – Each variant for a character True Breeding – Referring to organisms that produce offspring of the same variety over many generations of self-pollination Hybridization – In genetics, the mating, or crossing, of two true-breeding varieties P Generation – The true-breeding (homozygous) parent individuals from which F1 hybrid offspring are derived in studies of inheritance; P stands for “parental” F1 Generation – The first filial, hybrid (heterozygous) offspring arising from a parental (p generation) cross F2 Generation – The offspring resulting from interbreeding (self-pollination) of the hybrid F1 Alleles – Any of the alternative versions of a gene that may produce distinguishable phenotypic effects. Law of Segregation – Mendel’s first law, stating that the two alleles in a pair segregate (separate from each other) into different gametes during gamete formation Punnette Square – A diagram used in the study of inheritance to show the predicted genotypic results of random fertilization of genetic crosses between individuals of known genotype Homozygous – Having two identical alleles for a given gene Heterozygous – Having 2 different alleles for a given gene Phenotype – a visible trait Genotype – a non-visible genetic make up Testcross – Breeding of an organism of unknown genotype with a homozygous recessive individual to determine the unknown genotype. The ratio of phenotypes in the offspring reveals the unknown genotype Monohybrids – An organism that is heterozygous with respect to a single gene of interest. All the offspring from a cross between parents homozygous for different alleles are monohybrids. For example, parents of genotypes AA and aa produce a monohybrid of genotype Aa. Monohybrid Cross – A cross between two organisms that are heterozygous for the character being followed (or the self-pollination of a heterozygous plant) Dihybrids – An organism that is heterozygous with respect to two genes of interest. All of the offspring from a cross between parents double homozygous for different alleles are dihybrids. For example, parents of genotypes AABB and aabb produce a dihybrid of genotype AaBb Law of Independent Assortment – Mendel’s second law, stating that each pair of alleles segregates, or assorts, independently of each other pair during gamete formation; applies when genes for two characters are located on different pairs of homologous chromosomes or when they are far enough apar ton the same chromosome to behave as though they are on different chromosomes. Multiplication Rule – A rule of probability stating that the probability of two or more independent events occurring together can be determined by multiplying their individual probabilities Addition Rule – Rule of probability stating that the probability of any one of two or more mutually exclusive events occurring can be determined by adding their individual probabilities Complete Dominance – The situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable. Incomplete dominance – The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele

Codominance – The situation in which the phenotypes of both alleles are exhibited in the heterozygote because both alleles affect the phenotype in separate, distinguishable ways. Tay-Sachs disease – A human genetic disease caused by a recessive allele for a dysfunctional enzyme, leading to accumulation of motor and mental performance usually become manifest a few months after birth, followed by death within a few years. Pleiotropy – The ability of a single gene to have multiple effects. Epistasis – A type of gene interaction in which the phenotypic expression of one gene alters that of another independently inherited gene Quantitative Character – A heritable feature that varies continuously over a range rather than in an either-or fashion. Polygenic inheritance – An additive effect of two or more genes on a single phenotypic character Multifactorial – Referring to a phenotypic character that is influenced by multiple genes and environmental factors Pedigree – A diagram of a family tree with conventional symbols, showing the occurrence of inheritable characters in parents and offspring over multiple generations Carrier – In genetics, an individual who is heterozygous at a given genetic locus for a recessively inherited disorder. The heterozygote is generally phenotypically normal for the disorder but can pass on the recessive allele to offspring Cystic Fibrosis – A human genetic disorder caused by a recessive allele for a chloride channel protein; characterized by an excessive secretion mucus and consequent vulnerability to infection; fatal if untreated Sickle-cell disease – A recessively inherited human blood disorder in which a single nucleotide change in the ∝-globin gene causes hemoglobin to aggregate, changing red blood cell shape and causing multiple symptoms in afflicted individuals Huntington’s disease – A human genetic disease caused by a dominant allele; characterized by uncontrollable body movements and degeneration of the nervous system; usually fatal 10 to 20 years after the onset of symptoms Amniocentesis – A technique associated with prenatal diagnosis in which amniotic fluid is obtained by aspiration from a needle inserted into the uterus. The fluid and the fetal cells it contains are analyzed to detect certain genetic and congenital defects in the fetus Chorionic Villus Sampling (CVS) – A technique associated with prenatal diagnosis in which a small sample of the fetal portion of the placenta is removed for analysis to detect certain genetic and congenital defects in the fetus

Chapter 15 Chromosome theory of Inheritance – A basic principle in biology stating that genes are located at specific positions (loci) on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns. Wild Type – The phenotype most commonly observed in natural populations; also refers to the individual with that phenotype Sex-linked gene – A gene located on either sex chromosome. Most sex-linked genes are on the X chromosome and show distinctive patterns of inheritance; there are very few genes on the Y chromosome X-linked Gene – A gene located on the X chromosome; such genes show a distinctive pattern of inheritance Duchenne muscular dystrophy – A human genetic disease caused by sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue Hemophilia – A human genetic disease caused by a sex-linked recessive allele resulting in the absence of one or more blood-clotting proteins; characterized by excessive bleeding following injury Barr Body – A dense object lying along the inside of the nuclear envelope in cells of female mammals, representing a highly condensed, inactive x chromosome Linked Genes – Genes located close enough together on a chromosome that they tend to be inherited together Genetic Recombination – General term for the production of offspring with combinations of traits that differ from those found in either parent Parental Types – An offspring with a phenotype that matches one of the true-breeding parental (P generation) phenotypes; also refers to the phenotype itself Recombinant Types (Recombinant) – An offspring whose phenotype differs from that of the true-breeding P generation parents; also refers to the phenotype itself Crossing Over – The reciprocal exchange of genetic material between non-sister chromatids during prophase I of meiosis Genetic Map – An ordered list of genetic loci (genes or other genetic markers) along chromosome Linkage Map – A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes Map Unit – A unit of measurement of the distance between genes. One map unit is equivalent to a 1% recombination frequency Nondisjunction – An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other Aneuploidy – A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number Monosomic – Referring to a diploid cell that has only one copy of a particular chromosome instead of the normal two Trisomic – Referring to a diploid cell that has three copies of a particular chromosome instead of the normal two Polyploidy – A chromosomal alteration in which the organism possesses more than two complete chromosome sets. It is the result of an accident of cell division

Deletion – (1) A deficiency in a chromosome resulting from the loss of a fragment through breakage (2) a mutational loss of one or more nucleotide pairs from a gene Duplication – An aberration in chromosome structure due to fusion with a fragment from a homologous chromosome, such that a portion of a chromosome is duplicated Inversion – An aberration in chromosome structure resulting from reattachment of a chromosomal fragment in a reverse orientation to the chromosome from which it originated Translocation – (1) An aberration in chromosome structure resulting from attachment of a chromosomal fragment to a nonhomologous chromosome (2) During protein synthesis, the third stage in the elongation cycle, when the RNA carrying the growing polypeptide moves from the A site to the P site on the ribosome (3) The transport of organic nutrients in the phloem of vascular plants Down Syndrome – A human genetic disease usually caused by the presence of an extra chromosome 21; characterized by developmental delays and heart and other defects that are generally treatable or non-life-threatening Genomic Imprinting – A phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent

Chapter 16 Vocabulary DNA Replication - How a molecule of DNA is copied Transformation – a change in genotype and phenotype due to the assimilation of external DNA by a cell Bacteriophages – a virus that infects bacteria (also called a phage) Virus – DNA enclosed by a protective coat (most often a protein) Double Helix – the famous 2 strands of DNA Antiparallel – the subunits of the DNA run in opposite directions Semiconservative model – distinguished from a conservative model of replication where two parental strands somehow come back together after the process Origins of Replication – short stretches of DNA having a specific sequence of nucleotides Replication Fork – Y-shaped region where parental strands of DNA are being unwound Helicases – enzymes that untwist double helix at the forks and separates the two parental strands Single Strand Binding Proteins – bind to unpaired DNA to keep from repairing Topoisomerase – helps relieve strain by breaking, swiveling, or rejoining DNA strands. Primer –Initial nucleotide chain that is produced during DNA synthesis is a short chain of RNA Primase – enzyme that joins RNA nucleotides to make a primer during DNA replication using parental DNA DNA polymerases – enzymes that catalyze the synthesis of new DNA by adding nucleotides to a preexisting chain Leading strand – the new complementary DNA strand that is synthesized continuously along the template strand toward the replication fork in mandatory 5’ S 3’ direction of DNA Lagging strand – a discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5’ S 3’ direction away from replication fork Okazaki fragments – named after Japanese scientist – segments of lagging strands DNA ligase – enzyme that joins the sugar-phosphate backbones of Okazaki fragments into continuous strand DNA pol III – Using parental DNA as a template, synthesizes new DNA strand by adding nucleotides to an RNA primer of preexisting DNA strand DNA pol I – removes RNA nucleotides of primer from 5’ end and replaces them with DNA nucleotides Mismatch Repair – other enzymes remove and replace incorrectly ...