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84 Cards in this Set
- Front
- Back
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Who first tried to explain the inheritance of traits in humans? When? and What did they say traits were? |
Aristotle and Hippocrates, around 500 BC, "humors" and black bile, yellow bile, blood and phlegm |
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What is the theory of preformation? |
Fertilized egg contains complete miniature "homunculus" or human |
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What is the theory of epigenesis? Who discovered it and when? |
Theory: an organism develops from the fertilized egg into an adult in several stages; William Harvey in the 1600s |
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What is the cell theory? Who proposed it and when? |
"All organisms are composed of basic units called cells". Proposed by Schleiden and Schwann in 1830 |
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What is spontaneous generation? Who disproved it? |
"The creation of living organisms from nonliving components", Louis Pasteur |
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When did Charles Darwin publish the Origin of Species? |
1859 |
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What is the Origin of Species? What is a significant gap in his theory? |
Natural selection as an explanation of the mechanism of evolutionary change; gap: lack of understanding of the genetic basis of variationand inheritance |
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Who found the inheritance of traits? When did he publish it? |
1866 Gregor Mendel |
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What did Mendel's findings provide a basis for? |
Modern genetics |
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Who discovered the chromosomal theories? when? |
Sutton and Boveri, 20 years after Mendel |
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What is the characteristic number of chromosomes in eukaryotes? |
Diploid (2n) |
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What is the Chromosome Theory of Inheritance? |
Genes and chromosomes exist in pairs and genes are carried independently on chromosomes |
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What does the chromosome theory of inheritance explain? |
Genetic continuity from generation to generation |
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What showed that certain genes were responsible for eye colour and mutations of the genes are responsible for "differing" traits? |
Work on the Drosophila (fruit fly) |
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What are alleles in terms of genetics? |
Variants of a gene controlling a trait |
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Different alleles produce different ____? |
phenotypes |
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What is a genotype? |
Set of alleles for a given trait carried by an organism |
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Which is responsible for genetic responsible? DNA or chromosomes? |
DNA |
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Who discovered the Double-Helix? When? How? |
Watson and Crick - 1953 - using X-ray diffraction |
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What is the difference between the Watson and Crick base pairing and the Hoogsteen pairing? |
2 bonds : 3 bonds |
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What is the Central Dogma? |
DNA-transcription-RNA-translation-Protein |
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What are proteins? |
End products of gene expression; constructs of a combination of 20 amino acids |
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What are the shape and chemical nature of proteins determined by? |
linear sequence of amino acids |
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What causes Sickle Cell Anemia? |
Mutation in the amino acid sequence for hemoglobin; a single nucleotide in a gene changes one of 146 amino acids that encode for a molecule in hemoglobin |
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What forms the basis of biotechnology? |
Knowledge of molecular biology and genetics - recombinant DNA technology |
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Review question in chapter 1 |
review |
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What is DNA organized into units called? |
genes |
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What do the products of genes direct? |
Metabolic activities of cells |
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Genes are organized into what? |
chromosomes? |
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What do chromosomes serve to do? |
Transmit genetic info to new cells and from an organism to its descendants |
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What are the two major genetic continuity processes? |
Mitosis and meiosis |
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When are chromosomes visible? |
during cell division |
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When not dividing, what do chromosomes do? |
Genetic material unfolds and uncoils into a network mesh called chromatin |
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What is a plasma membrane? what is it made out of? What does it actively control? |
Out cell boundary, phospholipid bilayer, actively controls the cell environment |
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What is Glycocalyx? What is it composed of? What does it function to do? |
Covers the plasma membrane; composed of glycoproteins and polysaccharides; functions in cell recognition and identity; slime or layer |
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What are recognition sites? |
Cell surface markers include: AB, Rh, MN antigens, receptor molecues |
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What is the Nucleus? Where is it? |
Eukaryotes, contains DNA, chromatin and chromosomes, nucleolus, functions in rRNA synthesis |
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What is the nucleoid area? Where is it? |
Prokaryotes; concentrated DNA, no nuclear membrane, no nucleolus, DNA not extensively associated with proteins; DNA does not condense |
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What is the Cytoplasm? |
Remainder of the cell interior (minus nucleus) = cytosol + organelles + cytoskeleton |
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What is the cytoskeleton? What does it function to do? |
tubulin-derived microtubules and actin-derived microfilaments; maintains shape, facilitates mobility, anchors organelles |
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What is the endoplasmic reticulum? What does it do? Smooth and/or rough? |
Compartmentalizes and increases surface area for biochemical synthesis; smooth synthesizes acids and phospholipids; rough contains ribosomes and synthesizes proteins |
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What is the mitochondria? Where is it found? What does it do? |
House the oxidative phases of cellular respiration and generates ATP (energy-rich molecules), found in both plant and animal cells |
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What do chloroplasts do? Where are they found? |
Site of photosynthesis; plant cells and algae |
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What is similar about chloroplasts and mitochondria? |
Both contain their own DNA and can replicate themselves |
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What are centrioles? Where are they found? How many of them in pairs? What do they do? |
Found in animal and some plant cells; found in pairs: mature and smaller centriole; found in specialized region called the centrosome; organize spindle fibers |
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What are spindle fibers composed of? What are they important for? |
Composed of tubulin polymers; important for the movement of chromosomes during cell division |
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How are homologous chromosmes matched? |
Based on length and centromere placement (condensed region) |
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What is the centromere location with a metacentric chromosome location? |
Middle |
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What is the centromere location with a submetacentric chromosome designation? |
between middle and end |
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What is the centromere location with a submetacentric chromosome designation? |
between middle and end; creates p arm and q arm (p is short, q is long) |
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What is the centromere location with an acrocentric chromosome designation? |
Close to end; on p arm |
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What is the centromere location with a telocentric chromosome designation? |
at the terminal end (no p arm) |
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What is the genome of a species? |
Collective genetic information contained in a haploid set of chromosomes |
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What is a locus? |
A gene site along the length if a chromosome |
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What are alleles? |
Alternate forms of the same gene within the same species |
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What is biparental inheritance? |
One member of each homologous pair of chromosomes is derived from each parent - therefore, each diploid organism contains two copies of each gene |
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What is Mitosis? |
Forms the foundation for the development and growth of an organism |
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What does mitosis function to do? |
Would healing and normal cell replacement; complex process with many controls |
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What happens when mitosis is out of control |
leads to a tumor |
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What is cellular division? |
Karyokinesis and then cytokinesis (less complex) |
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What is karyokinesis? What does it result in? |
nuclear division; results in 2 identical daughter nuclei |
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What is cytokinesis? What does it result in? |
Encloses both new cells within a distinct plasma membrane |
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What three phases are involved in interphase? |
G1, S phase, G2 |
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What are the four steps of Mitosis? |
Prophase, Metaphase, Anaphase, Telophase |
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What is the S phase? |
Includes the replication of the DNA of each chromosome |
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What are the G1 and G2 phases? |
Gap phases during which intensive metabolic activity, cell growth and cell differentiation occur |
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In what phase of interphase does variation in length occur? |
In G1 (humans: 7 hrs) |
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What is the variation in G1? |
cells can withdraw from the cycle and become quiescent (G0 stage) |
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Cells in the G0 stage are viable and metabolically active but are _____ |
nonproliferative |
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Cancer cells manage to avoid or skip what phase? |
G0 |
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Cytologically, interphase is characterized by what? |
absence of visible chromosomes |
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Over half of mitosis is spent in what phase? |
Prophase |
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What happens to centrioles in prophase? |
Centrioles migrate to opposite ends of the cell |
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What happens to the nuclear envelope in prophase? |
Begins to break down |
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What happens with the chromatin fibers in prophase? |
Condense until chromosomes become visible |
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What happens to sister chromatids in prophase? |
Bound together at centromere |
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What is cohesin? What does it do? |
Protein complex that holds sister chromatids together |
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What is separase? What does it do? |
Enzyme that degrades cohesin? |
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What is shugoshin? What does it do? |
Protein that protects cohesin from being degraded by separase |
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What happens with spindle fibers and chromosome movement in prometaphase? |
Spindle fibers bind to each centromere via the kinetochore: assembly of protein associate with centromere Chromosomes move |
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What happens with chromosomes in metaphase? |
Migrate to the equatorial plate |
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What is the shortest stage of mitosis? |
Anaphase |
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What happens with sister chromatids in anaphase? |
Disjoin and migrate to opposite ends of the cell: disjunction |
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What happens with shugoshin and cohesin in Anaphase? |
Shugoshin must be degraded; cohesin complex is then cleaved by separase |
