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82 Cards in this Set
- Front
- Back
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Basis of growth, cell replacements, and tissue repair in multicelled species
Basis of asexual reproduction in many single-celled and multicelled species |
Mitosis
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After duplication, each consists of two double strands that remain attached to each other at a centromere until late in nuclear division
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Sister Chromatid
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Pieces of DNA with attached DNA proteins
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Chromosomes
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The area where sister chromatids are attached to one another
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Centromere
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A chromosome which has coiled itself into a compact unit prior to separation of sister chromatids
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Condensed Chromosome
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A chromosome consists of DNA that is wrapped around proteins and condensed
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Histones
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The smallest unit of structural organization in chromosomes
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Nucleosome
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Interval of cell growth before
DNA replication (chromosomes unduplicated) |
G1
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Interval of cell growth when the DNA is replicated (all chromosomes duplicated)
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S
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Interval after DNA replication; the cell prepares to divide
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G2
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A sequence of three stages (interphase, mitosis, and cytoplasmic division) through which a cell passes between one cell division and the next
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Cell Cycle
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consists of three stages, during which a cell increases in size, doubles the number of cytoplasmic components, and duplicates its DNA
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Interphase
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A dynamic network of microtubules that forms during nuclear division
Grows into the cytoplasm from opposite poles of the cell and attaches to duplicated chromosomes Microtubules from opposite poles attach to different sister chromatids and separate them |
Bipolar Spindle
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Chromosomes condense
Microtubules form a bipolar spindle Nuclear envelope breaks up Microtubules attach to the chromosomes |
Prophase
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All duplicated chromosomes line up midway between the spindle poles
Nuclear Envelope has disintegrated |
Metaphase
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Microtubules separate the sister chromatids of each chromosome and pull them to opposite spindle poles
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Anaphase
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Two clusters of chromosomes reach the spindle poles
A new nuclear envelope forms around each cluster |
Telophase
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The process of cytoplasmic division. Divides the cytoplasm and makes two new cells
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Cytokinesis
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Partitions the cytoplasm
A band of actin filaments rings the cell midsection, contracts, and pinches the cytoplasm in two Occurs during late anaphase and throughout telophase |
Contractile Ring
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produces genetically identical copies of a parent (clones)
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Asexual Reproduction
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A sequence of three stages (interphase, mitosis, and cytoplasmic division) through which a cell passes between one cell division and the next
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Cell Cycle
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consists of three stages, during which a cell increases in size, doubles the number of cytoplasmic components, and duplicates its DNA
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Interphase
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A dynamic network of microtubules that forms during nuclear division
Grows into the cytoplasm from opposite poles of the cell and attaches to duplicated chromosomes Microtubules from opposite poles attach to different sister chromatids and separate them |
Bipolar Spindle
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Chromosomes condense
Microtubules form a bipolar spindle Nuclear envelope breaks up Microtubules attach to the chromosomes |
Prophase
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All duplicated chromosomes line up midway between the spindle poles
Nuclear Envelope has disintegrated |
Metaphase
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Microtubules separate the sister chromatids of each chromosome and pull them to opposite spindle poles
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Anaphase
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Two clusters of chromosomes reach the spindle poles
A new nuclear envelope forms around each cluster |
Telophase
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The process of cytoplasmic division. Divides the cytoplasm and makes two new cells
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Cytokinesis
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Partitions the cytoplasm
A band of actin filaments rings the cell midsection, contracts, and pinches the cytoplasm in two Occurs during late anaphase and throughout telophase |
Contractile Ring
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produces genetically identical copies of a parent (clones)
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Asexual Reproduction
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introduces variation in the combinations of traits among offspring
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Sexual Reproduction
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Regions in an organism’s DNA that encode information about heritable traits
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Genes
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Different forms of the same gene
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Alleles
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A two stage nuclear division in which the parental number of chromosomes in each daughter nucleus becomes “haploid”
(1 diploid ------> 4 haploid) |
Meiosis
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Contains half the number of chromosomes. (one of each “homologous pair” (1n)
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Haploid
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Have the same length, shape, centromere location and gene sequence. They line up next to one another during meiosis. (X and Y chromosomes pair)
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Homologous Chromosomes
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(like somatic cells) Are diploid, meaning they have 2 chromosomes of each type in the nucleus.
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Germ Cells
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Are haploid cells that arise as a result of meiosis in germ cells.
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Gametes
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How many chromosomes are in a human gamete?
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23 Chromosomes
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Each duplicated homologous chromosome is separated from its partner
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Meiosis I
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Sister chromatids are separated
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Meiosis II
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The process by which a chromosome and its homologous partner exchange heritable information in corresponding segments
Occurs during condensation in prophase I |
Crossing Over
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The fusion of two haploids gametes
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Fertilization
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Heritable units of information about traits
Parents transmit genes to offspring Each gene has a specific locus on a chromosome |
Genes
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A permanent change in a gene
May cause a trait to change |
Mutation
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has nonidentical alleles for a trait
Offspring of a cross between two individuals that breed true for different forms of a trait are hybrids |
Hybrid
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Nonidentical alleles of a gene
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Heterozygous
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Identical alleles of a gene
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Homozygous
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The process by which information in a gene is converted to a structural or functional part of a cell or body
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Gene Expression
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The particular alleles an individual carries
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Genotype
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An individual’s observable traits
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Phenotype
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Diploid cells have pairs of genes on pairs of homologous chromosomes
The two genes of each pair separate during meiosis, and end up in different gametes |
Mendel's Law of Segregation
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Many genes are sorted into gametes independently of other genes
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Mendel's Law of Independent Assortments
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Two nonidentical alleles of a gene are both fully expressed in heterozygotes, so neither is dominant or recessive
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Codominance
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Genes with three or more alleles in a population
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Multiple Allele Systems
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One allele is not fully dominant over its partner
The heterozygote’s phenotype is somewhere between the two homozygotes |
Incomplete Dominance
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Two or more gene products influence a trait
Typically, one gene product suppresses the effect of another |
Epistasis
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One gene product influences two or more traits
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Pleiotropy
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The basis of sex – human males have XY sex chromosomes, females have XX
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Sex Chromosomes
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Chromosomes that are the same in males and females
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Autosomes
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Achondroplasia and Huntington's Disease
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Autosomal Dominant
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A micrograph of all metaphase chromosomes in a cell, arranged in pairs by size, shape, and length
Detects abnormal chromosome numbers and some structural abnormalities |
Karyotype
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Relatively normal torso
Arms and legs very short Head is large, forehead prominent Most individuals reach adult height of 4 ft Caused by Mutation in gene |
Achondroplasia
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Missing or Mutated genes result in uncontrolled growth
Six or more tan spots on the skin (café au lait) Freckles that appear under arm or in groin by 7 years of age 2 or more benign tumors under skin or deeper Optic glioma (tumor on optic nerve) Bone defects Family history No Treatment |
NF1
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Tall, long limbs
Arachnodactyl (spider fingers) Loose joints Scoliosis-curvature of the spine Sternum points out or is caved in Defect in fibrillin (connective tissue) Fibrillin-connects fibrils side by side, keeps collagen strong (holds tissues together) Heart and blood vessel problems are common symptoms, lung problems, eye problems and skeletal abnormalities Treatment: Control blood pressure, surgery on aorta |
Marfan Syndrome
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A standardized chart of genetic connections
Used to determine the probability that future offspring will be affected by a genetic abnormality or disorder |
Pedigree
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Galactosemia, Cystic fibrosis, Tay Sachs, Sickle Cell Anemia
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Autosomal Recessive
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The defect causes major problems in mucus producing glands. Effects are primarily in the respiratory and digestive system.
The mucus clogs lungs, causing breathing problems. The mucus is a breeding ground for bacteria, leading to infections CF patients usually die in early adulthood, usually from infections (pneumonia) Coughing or wheezing Repeated lung infections, such as pneumonia and bronchitis Shortness of breath Poor growth, in spite of a big appetite Intestinal blockage, called meconium ileus Greasy, bulky stools Infertility in affected males Treatment is Daily repsiratory therapy, mucus thinners, bronchodilators, lung transplant in severe cases |
Cystic Fibrosis
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This condition leads malnutrition, diarrhea, vomiting, and damage to eyes, liver, and brain
If no treatment, patients die young When placed on diet that excludes all dairy products, the symptoms may not be as severe. |
Galactosemia
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Fatal genetic disorder (lipid storage disease)
Progressive degeneration of Central Nervous System |
Tay Sachs
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Part of the sequence of DNA becomes oriented in the reverse direction, with no molecular loss
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Inversion
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DNA sequences are repeated two or more times; may be caused by unequal crossovers in prophase I
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Duplication
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Loss of some portion of a chromosome; usually causes serious or lethal disorders
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Deletion
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Typically, two broken chromosomes exchange parts
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Translocation
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Occurs when there are more than 2 “sets” of chromosomes. This is not viable in humans. Seen in miscarried fetuses.
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Polploidy
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is the failure of 1 or more chromosomes to separate during meiosis. This can occur at either Anaphase I or Anaphase II. The result is an individual with an abnormal chromosome number.
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Nondisjunction
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A term that defines any deviation from a full chromosome complement. (too many or too few chromosomes) When a zygote is formed with too few chromosomes, only XO (Turner syndrome) has a chance to survive
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Aneuploidy
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Occurs when a zygote receives 3 of one type of chromosome.
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Trisomy
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Bleeding caused by lack of blood-clotting protein
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Hemophilia A
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Inability to distinguish certain colors caused by altered photoreceptors in the eyes
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Red-Green Color Blindness
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Degeneration of muscles caused by lack of the structural protein dystrophin
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Duchenne Muscular Dystrophy
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Hemophilia A, Red-Green Colorblindness, Duchenne muscular dystrophy
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X- Linked Diseases
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