Term
| Lab 7: Analysis of Heredity: Fruit Fly Crosses Objective |
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Definition
| Observe mutant and wild-type fruit flies and set up fruit fly matings to examine sex-linkage as an exception to Mendel's Law of Independent Assortment. |
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Term
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Definition
| factors that control phenotypic traits |
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Term
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Definition
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Term
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Definition
two alleles that are the same at a specific genetic locus
ex. AA |
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Definition
two alleles that are different at a specific genetic locus
ex. Aa |
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Term
What is Mendel's Law of Segregation?
How are meiotically divided cells different from mitotically divided ones? |
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Definition
Alleles are separated from each other during meiotic division so daughter cells receive different copies of alleles.
Mitotically divided daughter cells have identical genetic make up to the parent cell. |
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Term
| What is Mendel's Law of Independent Assortment? |
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Definition
| The segregation of the first pair of alleles will be independent of the second. |
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Term
| What are two exceptions to Mendel's laws? |
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Definition
| linked genes and sex chromosomes |
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Term
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Definition
| Genes that do not segregate independently but stay together |
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Term
| Why are males considered hemizygous? How does this explain the fact that males display a higher frequency of recessive traits than females? |
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Definition
| Because the Y chromosome is much smaller than the X chromosome and has fewer genes. So if a male inherits a recessive X-linked gene, he will express the recessive phenotype. |
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Term
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Definition
| A chromosome that does not influence the development of sexual characteristics of an individual. |
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Term
| Why do we do experimental crosses with drosophila melanogaster? |
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Definition
| To determine whether particular traits are governed by genes are sex-linked or autosomal. |
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Term
| What is a wild-type allele? What is a mutant type allele? |
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Definition
| The standard genotype is the wild type allele. Strains of alleles that differ are called mutant. |
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Term
| How is the nomenclature for Drosophila genetics written? |
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Definition
Genes are named for the mutant phenotype that mutant alleles produce. If the mutation is dominant it is capitalized, if it is recessive, it is lower case.
Ex. Curly wings are dominant
Wild type= flat wings, C
Mutant = curly wings, C+ |
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Term
| What are the main differences between male and female Drosophila? |
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Definition
Females: striped abdomen, pointy anal plate,
Males: darker abdomen, shorter/rounded anal plate, sex combs |
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Term
| Why are Drosophila the model organism? |
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Definition
| They have a short life cycle (14 days egg to adult), they produce many offspring, males and females are sexually dimorphic, and the phenotypes are easy to observe. |
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Term
| Lab 8: Microscopy of Eukaryotic Cellular Components Objective |
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Definition
| Examine characteristics of different types of eukaryotic cells using the light microscope and detect the nuclei, vacuoles, cell membranes, cilia, chloroplasts, and cell walls |
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Term
| Match the kingdoms with the representatives: protists, human, elodea (onion), yeast, plants, fungi, animals, tetrahymena, |
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Definition
Kingdom Representatives
Protists Tetrahymena
Fungi Yeast
Plants Elodea, Onion
Animals Humans |
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Term
| What did we look for in the onion? |
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Definition
| organelles: nuclei, vacuoles, cell walls, plasmodesmata |
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Term
| What happens to the onion when it is in a hypertonic solution? |
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Definition
| The red pigment moves out of the well, the large vacuole shrinks and rips away from the cell wall |
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Term
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Definition
| When the protoplast of each cell bounded by the cell membrane shrinks and pulls away from the cell wall |
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Term
| What happens to elodea during plasmolysis? |
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Definition
| The central vacuole shrinks, the green color moves out of the cell, and the plasmolyzed elodea cells are irregular |
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Term
| What is cytoplasmic streaming? Does it move in the same direction in all cells? |
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Definition
Cytoplasmic streaming is the flow that carries nutrients, metabolites, and genetic information to other parts of the cell occurring along actin filaments in the cytoskeleton. The actin filaments drive cytoplasmic streaming typically in one direction.
It does not move in the same direction for all cells |
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Term
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Definition
| the process of ingestion of particles by cells |
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Term
| How does the tetrahymena ingest food particles? |
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Definition
| It uses the surrounding cilia to move food particles to the food vacuole |
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Term
| Where does the vacuole go after it has separated from the gullet in the tetrahymena? How many vacuoles for? If multiple form, do they move along the same path? |
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Definition
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Term
| Do food vacuoles accumulate in any particular region of the tetrahymena? |
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Definition
| Yes, they accumulate on one side of the cell so the cilia can efficiently sweep food into the vacuole |
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Term
What did we observe in the saccharomyces cerevisiae (fungus)?
Is there a difference between heated and unheated cells? |
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Definition
By adding phosphate-buffer methylene blue, some cells turn blue and others stay white. This is an example of the selective permeability of cell membranes.
The heated cells are dead and no longer have a working membrane so they all turn blue. |
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Term
| How do you improve the visibility of organelles in the squamoush epithelium tissue cells (human cheek)? |
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Definition
organelles: Nucleus, cell wall
Add ethanolic methylene blue solution or reduce the light intensity |
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Term
| How can you tell that fungus is a eukaryotic cell? |
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Definition
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Term
| Lab 9: Analysis of Heredity: Fruit Flies Part II Objective |
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Definition
| Analyze results of live fruit fly matings to investigate sex-linkage using chi square to support the results |
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Term
| What is the Chi Square (X^2) test? |
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Definition
A test that uses statistics to evaluate a data set to see whether it fits a model or hypothesis using the equation:
X^2 = ∑ (observed data - expected data)^2/E |
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Term
| What is the degrees of freedom? |
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Definition
| The number of data variations minus one. This is important in reading the Chi Square table |
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Term
| What is the probability value? |
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Definition
| A number the indicates the likelihood that the difference between observed and expected significantly supports the hypothesis/model, not random variation. |
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Term
| Lab 10: Phosphatase Activity Objective |
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Definition
| Prepare a standard curve for p-nitrophenolate concentrations and observe the effect of a phosphatase on the rate of reaction in which p-nitrophenylphosphate loses a phosphate group and gets converted into to p-nitrophenol (product) to determine the identity of an unknown phosphatase based on pH performance |
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Term
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Definition
| Enzymes are usually proteins that catalyze a chemical reaction that changes a substrate into a product. |
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Term
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Definition
| Phosphatases are a group of enzymes that catalyze removal of a phosphate group form a molecule. |
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Term
| How does phosphatase work to remove the phosphate group from the molecule? What does it need for the opposite reaction? |
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Definition
| It requires water for a hydrolysis reaction. The opposite reaction is a condensation reaction in which water is a product. |
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Term
| What are enzymes that catalyze the addition of a phosphate group called? |
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Definition
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Term
| What are some functions of phosphatases? |
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Definition
As secreted enzymes in the intestine, phosphatases break down food into smaller digestible products to be absorbed or metabolized.
During germination in seeds, active phosphatases store food to be used by an emerging seedling.
In lysosomes or phagocytic cells, phosphatses can help digest particulate matter captured during phagocytosis.
Active phosphotases in the cytoplasm recycle phosphorus in metabolism or remove phosphate groups from proteins whose activities are regulated by adding and removing phosphate groups |
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Term
| What are the effects of NaOH when added to the phosphatase? Is time a factor? |
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Definition
NaOH converts p-nitrophenol (colorless) to p-nitrophenolate (yellow)
NaOH also stops the activity of the phosphatase enzyme so if the reaction is stopped sooner, there will be fewer products. |
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Term
| What does the standard curve measure in determining phosphatase activity? |
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Definition
| It measures the relationship between between light absorption and the concentration of the product, p-nitrophenolate, showing the rate of catalysis in molar units of product formed per unit time. |
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Term
| How did we find 'E' and 'A' for determining the relationship between light absorption and the concentration of p-nitrophenolate? |
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Definition
| By measuring different vials of varying concentrations of p-nitrophenolate in the photospectrometer we found A at 405nm. Then we plotted the points on a graph and made a standard curve, the slope of which is E. |
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Term
| How do you examine the effect of an enzyme on reaction rate? |
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Definition
Compare the rate of hydrolysis of p-nitrophenylphosphate to p-nitrophenol with and without enzyme phosphatase using NaOH as a stopper and physical indicator.
y = rate, x = time |
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Term
| How are calf phosphatase and wheat phosphatase different? |
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Definition
| Calf phosphatase has optimal basic pH while wheat has optimal acidic pH. |
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Term
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Definition
| The pH at which enzymes exhibit their greatest activity and create the most product. |
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Term
| Lab 11: Cell Fractionation Objective |
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Definition
| Isolate chloroplasts from spinach leaves and estimate the amount of chlorophyll a per chloroplast by using spectrophotometry to determine concentration of chlorophyll a in chloroplasts and using a hemocytometer to determine the concentration of chloroplasts in spinach extracts. |
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Term
| Why is there green pigment in the leaves and stems of plant organs? |
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Definition
| Because of the presence of green pigments called chlorophyll a and chlorophyll b in the chloroplasts. The remainder of the plant cell is basically colorless. |
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Term
| Where do green organelles lie in the cell? |
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Definition
| In the cytoplasm unattached to any other cellular components. |
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Term
| What happens when the cell wall is disrupted? |
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Definition
| The plasma membrane breaks and subcellular components are released as separate particles |
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Term
| After blending the spinach leaves we filtered them through a cheese cloth. What does this first filtration remove? |
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Definition
| The first fiiltration removes large debris like cell walls and unbroken cells. What remains are nuclei, chloroplasts, mitochondria, ribosomes, small membrane vesicles, and soluble components. |
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Term
| After filtration we use a low + medium speed centrifugation to separate the remaining large bodies from the filtrate. What is left in the supernatant? |
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Definition
| Mitochondria, ribosomes, and soluble components. |
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Term
| How could we further purify the chloroplasts? |
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Definition
| By using repeated rounds of differential centrifugation |
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Term
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Definition
| An instrument used for counting cells under a microscope. It is broken in to a grid to make counting easier. It holds 1mm^2. |
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Term
| How do you determine the undiluted concentration of chloroplasts in the suspension? |
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Definition
| Use (c1)(v1) = (c2)(v2) and solve for v1, this is also your 'C' |
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Term
| What is the name of the Columbia professor who conducted fly experiments? |
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Definition
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