Download Study Guide 1st Lab Exam – Monday 7/13/09

Study Guide 1st Lab Exam – Monday 7/13/09
Study recaps, quizzes, quiz guides, lab manual figures and charts.
Microscopy Lab
1. Ocular lens = Eye-piece – 10X…..X indicates magnification.
2. Objective lenses – Low Power = 10X , High Power = 43X and Oil Immersion = 100X
3. Magnification = size of the image / size of the object
4.
Low power magnification (10X * 10X) = 100; High Power Magnification (10X * 40X) = 400 and Oil
Immersion magnification (10X * 100X) = 1000 Table 2.3
5. Stereoscopic = Dissecting Microscope: fig 2.6, page 16
Compound Microscope
Stereoscopic Microscope
1 Source of light
Transmitted
Mostly reflected
2 objects
studied
Thin, transparent, thick object are cut
with microtome and stained
Thick, opaque, objects studied,
living materials studied, surface
study of natural objects
3 type of image
2-D
3-D
6. Starch + Iodine sol (yellow)  Blue-black color
7. Diffusion is movement of substances from high concentration to low concentration. It is fastest in
air, intermediate in liquid and slowest in solids. It is due to kinetic energy of molecules.
8. Osmosis is the net movement of water from its higher concentration to its lower concentration
through a semi-permeable membrane. In the thistle funnel experiment to demonstrate osmosis. A
thick corn syrup is filled in the thistle funnel and animal membrane is bound at its lower end. It is
lowered in the beaker with water. A concentrated (hypertonic) solution and a dilute (hypotonic)
solution are separated by a semi-permeable membrane. The % of water in thistle funnel is much less
than the water in the beaker. So water from its higher concentration in beaker moves (net) inside
the thistle funnel. This makes the level of red liquid inside move up in the tube even against the
force of gravity.
9. Dialysis is the diffusion through cell membrane and is used to separate different substances (glucose
and starch) or glucose and urea in kidney dialysis when the kidneys fail and urea levels get very high
in blood.
10. Solutions A and B are separated by a semi-permeable membrane. A has 6% sugar so it has 94%
water. Sol B has 2% sugar so it has 98% water. Osmosis is the net movement of water from its higher
concentration to its lower concentration. Therefore water has net movement from B  A. Solution A
is hypertonic and Solution B is hypotonic.
Solution A = 6% Sugar Solution
Solution B = 2% sugar solution
11. In Thistle funnel we have 50% corn syrup and beaker has 100% water. Water from beaker = 100%
has a net movement (Osmosis) to the thistle funnel having 50% water.
12. Elodea cell placed in saturated salt solution (Hypertonic) loses water due to osmosis and shrinks at
the center. Process is called Plasmolysis.
13. Elodea cell placed in water (Hypotonic) gains water due to osmosis and creates higher Turgor
Pressure and choloroplasts and nucleus are pressed against the cell wall.
14. Labs on Respiration and Photosynthesis. We used pH indicator Phenol Red – red in color at pH = 7 or
above and yellow in color at pH = below 7. If CO2 is added, respiration or fermentation, to a system
it combines with water to form H2CO3, Carbonic acid which yields H+ ions leading to lowering of pH
and color changes from red to yellow. The reverse happens when CO2 is taken, photosynthesis, out
of a system, H+ ions are removed and pH is raised – color changes from yellow to red.
15. Photosynthesis: 6CO2 + 6H2O + Sunlight  C
6H12O6 + O2. The 2 photosystems having Chlorophyll and
other pigments, present in leaves, use the energy of sunlight to produce Glucose. It means removal
of CO2 or addition of O2 to a system indicates occurrence of photosynthesis. Removal or addition of
16. 1st Lab: Hypothesis: Green parts of Coleus leaf – have chlorophyll and perform photosynthesis
leading to synthesis of glucose and starch. Yellow parts lack chlorophyll, therefore no
photosynthesis no starch. Experiment: We break cell membranes by boiling the leaf in water and
transfer it to alcohol which extracts the pigments and make the leaf white. On pouring Iodine the
parts having green colors originally, turn black, indicating presence of starch and photosynthesis.
Originally yellow parts turn brown indicating absence of starch and photosynthesis. Conclusion –
Chlorophyll is necessary for photosynthesis.
17. 2nd Lab: When you blow your breath in phenol red addition of CO2 lowers the pH and changes the
color from red to yellow. The half yellow phenol red having an Elodea twig changes back its color to
red because Elodea performs photosynthesis and removes CO2 from the solution. The other half
keeps its red/pink color. Conclusion - Photosynthesis uses CO2 to synthesize glucose.
18. Fermentation is the breakdown of glucose in absence of O2. Microorganisms like yeast break glucose
to ethyl alcohol and CO2. In fermentation tube no oxygen is available and when fermentation takes
place CO2 accumulates at the top of the tube. This experiment showed the role of substrate sucrose
(sugar) versus protein. It also compared the effect of temperature on fermentation. The tube with
sucrose at normal temperature showed maximum production of CO2 or speed of fermentation.
When the tube with sucrose was placed in Fridge the gas released was minimal. It indicated
enzymes responsible for fermentation were not working efficiently at cold temperature of the
fridge. The tube with protein at room temperature also had little fermentation because main
substrate is sugar and not protein.
19. Peas were placed in phenol red. Peas undergo aerobic respiration and produce CO2. It lowers the pH
by adding CO2 and changes the color from red to yellow.
20. I will ask multiple choice questions from DNA lab and ask you to write DNA from DNA or m-RNA
from DNA.
21. Genetics Labs – Human traits like Free – attached ear lobes, Widow peak – straight hairline, PTCTasters – non tasters; Inheritance of seed color and shape in CORN.
22. Monohybrid Ratio 3:1 when F1 X F1 is crossed. I can say Yy X Yy
23. Monohybrid Test Cross ratio is 1:1. That is F1 X recessive parent or Yy X yy.
24. Dihybrid Cross ratio is 9:3:3:1 when F1 X F1 or YyRr X YyRr.
25. Dihybrid Test cross ratio is 1:1:1:1 when F1 X recessive parent or YyRr X yyrr.
26. Genetic Numericals
1st problem – A person with blood group AB is married to a female with blood group O. What will be the
possible blood groups of their children?
I.
One parent is AB and other is O.
II.
Genotypes should be IAIB and ii.
III.
Gametes should be IA and IB for one parent and only i for the other parent.
IV.
Only 2 combinations are possible IAi and IBi. So children could be ‘A’ and ‘B’ blood groups.
i
IA
IB
IAi
IBi
2nd problem - What is the expected phenotypic ratio of the following cross: AaBb × AaBb? In this
example, A is dominant to a, and B is dominant to b.
I.
A cross between AaBb X AaBb is a dihybrid cross so the ratio should be 9:3:3:1
3rd problem-A true-breeding plant that produces yellow seeds is crossed with a true-breeding plant that
produces green seeds. The F1 plants have yellow seeds. What is the expected phenotypic ratio of seed
color of the offspring of an F1 × F1 cross?
II.
A true breeding yellow plant should be YY is crossed to a true breeding green plant, should
be yy. F1 plants are yellow = Yy. When F1 X F1 is crossed it is a cross of Yy X Yy. So it is a
monohybrid cross and the ratio should be 3:1.
4th problem - Attached earlobes are recessive to free earlobes. What genotypic ratio is expected
when an individual with attached earlobes mates with an individual heterozygous for free earlobes?
III.
Individual heterozygous for free earlobes is Ff and is crossed with attached earlobes ff.
So Ff X ff is a test cross gives the ratio of 1:1
5th problem - Round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant
to green seeds (y). What is the expected phenotypic ratio of a cross between an RrYy and an rryy
individual?
IV.
A cross between RrYy X rryy is a dihybrid test cross and ratio is 1:1:1:1.
Taxonomy
27. Learn about 3 domains and 4 kingdoms of Eukarya with their characteristics.
Bacteria
28. Bacteria have cell wall made of peptidoglycan. These lack a nucleus or any membrane bound
organelles; the only organelle present is ribosomes for protein synthesis. They divide by binary
fission. Some bacillus type bacteria produce endospores. For example Anthrax bacteria normally
cause infections to animals but can be used as bio-warfare or terrorist attacks.
29. Gram+ bacteria have thicker peptidoglycan in cell wall and retain purple color. Common example is
Bacillus bacteria that have a rod like body. Gram- bacteria lose the purple color on washing with
alcohol. These are stained with red saffranin stain. Example is small spherical Coccus bacteria.
Streptococcus causes strep throat infections.
Protists
30. Photosynthetic protists
31. Unicellular aquatic autotrophic protists include diatoms, dinoflagellates and euglenas.
32. Diatoms are most important producers on earth. No flagella and body covered by 2 pieces of silica
shell.
33. Dinoflagellates have cellulose plates and 2 flagella in grooves at 90 ⁰ to each other. These cause the
red tides.
34. Euglena has 1 flagellum at anterior end. It has one nucleus and chloroplasts for photosynthesis.
35. Algae are aquatic multicellular autotrophic protists. Red algae can grow in deepest marine waters.
Brown algae forms the kelp forests present off-coast California. Green algae can be unicellular –
Chlamydomonas has 2 flagella and single basin shaped chloroplast. Spirogyra has unbranched
filaments with spiral chloroplasts. Volvox is a colonial alga formed of thousands of Chlamydomonas
like organisms in a spherical body. It has daughter colonies developing inside it.
36. Protozoan protists are animal like and eat food and form food vacuoles to digest it inside them.
37. Amoeba has a continuously changing body due to formation and withdrawal of pseudopodia. Body
is covered with only cell membrane. Pseudopodia help amoeba in capturing food besides
locomotion.
38. Paramecium has a fixed body shape like the sole of a slipper. Body is covered with a thick Pellicle. It
locomotes with cilia. It has a bigger and a smaller nucleus. It captures food with oral groove lined
with cilia.
39. Trypanosoma has a single flagellum and occurs in human blood outside red blood cells. It casuses
sleeping sickness.
40. Plasmodium is a blood parasite that occurs inside red blood cells and causes Malaria disease. No
locomotory appendage is present in them.
41. Slime moulds are fungus like protists but have both Ingestive and absorptive nutrition. These can be
unicellular or multicellular. Only reproductive structures are covered with cell walls. These are good
decomposers.
Fungi
42. Fungi are not plants but a separate kingdom. The cell wall material is Chitin. Instead of filaments like
in algae, fungi has thin thread growing at apical ends called Hyphae. Total fungal body formed of all
hyphae of one individual is called Mycelium. Fungi like animals are heterotrophs and secrete
enzymes to digest food. But they grow on food and secrete enzymes outside and then absorb
digested food.
43. Zygospore Fungi = Zygomycota – Rhizpus, the bread mold. Body develops dark sporangia and
produce bulk of spores. It reproduces sexually by fusion of hyphae and produce thick walled
Zygospores.
44. Sac Fungi = Ascomycota – Yeast, a unicellular fungus, reproduces asexually by budding. It
reproduces sexully making asci each having 4 or 8 ascospores. Yeast is used widely in bakeries and
breweries. Baker’s yeast. Some yeasts cause human diseases. Peziza is also an ascomycote and you
obserbed its ascocarp with asci in demo slides. Each ascus has a row of 8 ascospores. Examples
morels, truffles and yeasts.
45. Club Fungi = Basidiomycota – Mushroom is a fruit body Basidiocarp. Most of the mycelium lies
inside soil. It produces basidia. Each basidium forms 4 spores by budding. Each spore germinates to
form Monokaryotic mycelium. Tips of 2 different monokaryotic hyphae fuse to form Dikaryotic
mycelium. Dikaryotic mycelium grows and extensively and forms the basidiocarp that emerges
outside. Most mushrooms are edible. Basidiospore  monokaryotic mycelium  fusion 
dikaryotic mycelium  basidiocarp (mushroom)  gills  basidia  basidiospore.
46. Many club fungi cause plant diseases. For example, Rusts and Smuts.
47. Imperfect Fungi lack sexual reproduction or it has not been discovered. Most are Ascomycotes.
Penicillium is very important member and source of Penicillin the 1st antibiotic drug. Penicillium
reproduces asexually by Conidia. Aspergillus also belongs to this group.
48. Models: animal cell and plant cell; mitosis in animal or plant cell; red blood cell tubes in different
concentration solutions with reading paper behind them; osmosis demonstration with thistle funnel
with corn syrup in water beaker; A sensitivity plate for antibiotic action; Euglena, Amoeba,
Paramecium; table 26.1 showing different types of protists; Fig of Vorticella 26.8; Fig 26.5 of
Trypanosoma; fig 26.10 of Plasmodium; specimans of lichen and mushroom.
49. Tables and figures: table 4.1 – eukaryotic structures in animal and plant cells; functions of cell
organelles; figure 4.10 showing Elodea cells with plasmolysed cell; table 24.1 prokaryotic versus
eukaryotic cells; fig 24.3 showing 3 basic forms of bacteria; root nodules of peanut plant with
Rhizobium for nitrogen fixation; fig 24.10a,b of Oscillatoria and Nostoc (with heterocysts); fig 25.3
showing different stages of Spirogyra; fig 25.6 of Volvox; Table 27.1 showing different classes of
fungi; fig 27.14 of life cycle of mushroom. Figure numbers may be different in your lab manuals.
Therefore, I added descriptions to figures or tables.
50. I will give you a chance to ask me any questions before the mid-lab exam.