User:Emilie Cassano/Notebook/Biology 210 at AU

From OpenWetWare
Jump to: navigation, search

Lab I- Transects

==Table 1 summarized==- observation of the Volyocene line Chlamydomonas: 1 cell, .75 um, flagella, stogma. No reproductive specialization visible. Gonium:2-4 cells, 1 um in size, has flagella for mobility, no reproductive specalization visible. Volvox:6-8 cells, 2 um in size, has flagella and a visible nucleus. Has male/female differentiation, an interior and posterior layer.

-what is the significance of cell specialization across the three genera? Because these lifeforms inhabit the same niche, it is important that they occupy different levels and aspects of the area so as to not impede on the others. Cells specialize in relatively different ways in order to maintain their position in the niche.

-Does evolution always move towards increased complexity? Provide an example. Evolution does not always move towards increased complexity because we still have extremely simple lifeforms thriving after hundreds of millions of years. Viruses, for example, are extremely simple lifeforms which are more successful than some complex lifeforms, like the recently extinct Thylacine.

Transect 5: The transect lays indirectly on the walkway dividing the quad between Hurst and MGC. It contains a grassy plot and a landscaped section with rosebushes and mulch. The lower left-hand corner is cement. There is moss present, along with some dead leaf and other plant matter. Few, if any, forms of complex Eukaryotic life were observed in the transect. Abiotic matter included the cement walkway and a few small pebbles. No litter or abiotic waste was observed in the transect. Due to the unusually low temperature, insects and other expected animals were not observed.

Lab 2:Protists

Transect 5 hay infusion jar observations: 

The jar was relatively clean-smelling with no substantial odour aside from the brackish water. Mud had settled to the bottom of the hay infusion with water of the consistency of black tea, containing dark leaves floating at the top.

"Take a few samples for microscopic observation. You should observe organisms from two different niches. It is a good idea to remove some plant matter as one of the areas to observe. Why might the organisms differ near vs away from the plant matter? o Note exactly where you obtain these samples from the culture. oCarefully use a dropper to place a small drop of liquid from the culture onto a microscope slide and then place a cover slip on top."

Two samples were taken and made into simple wet-mount slides, one from the muddy bottom and one from the leaves at the top. The samples differed because different organisms occupy different niches within this tiny ecosystem. Some organisms fed off of the plant matter near the top, and others resided in the mud at the bottom. Among the creatures located in the slides were (guessed to be) spirostomum and several amoeba-looking species in the mud as well as some form algae. These structures were largely immobile. Also, various types of paramecium (suspected to be paramecium aurelia and paramecium bursaria) running around the plant matter (moving with cilia), accompanied by some form of immobile brown plant-organisms.

Choose one of the organisms and describe how this species meets all the needs of life as described on page 2

The paramecium and plant cells meet the requirements to be classified as living things. Both contain a nucleus and organelles functioning to create ATP. Both have DNA matter which they pass on when they reproduce. (drawings to be added as soon as formatting is figured out- can refer to physical lab notebook)

test tubes were prepared with various concentrations of bacteria samples, then transferred to gel agar plates and stored for a week to be observed in lab 3. (drawing exists in physical lab notebook, to be added with formatting)

If the hay infusion culture had been observed for another two months what changes would you predict to occur?

The bacteria and fungus would slowly build its own ecosystem. The species that thrive in that particular (warmer) environment with the given nutrients would multiply and beat out other species that may be existing and used to the colder climate (it was 2degrees C on the day samples were collected.)

What selective pressures effected the compositions of your samples?

The samples were taken randomly and so there is the chance that the particular sample contained an amount of microorganisms disproportionate to the actual transect. Fertilizers, lawn treatments, and other outside chemicals may mix with different parts of the hay infusion where they did not come into contact before. Also, as the temperature increased suddenly, certain lifeforms may have become active that were inactive before, changing the balance of the ecosystem.

Lab 3: Microbiology

Do you think any Archaea species will have grown on the agar plates? Why or why not?

It is highly unlikely that Archaea have grown on the agar plates. Archaea tend to prefer extreme environmental conditions, such as extremely high or low temperatures or Ph. Because the samples were collected from a temperate environment that was not especially salty, there are few aspects to suggest that Archaea would thrive there.

Explain why the appearance or smell might change week to week?

Different bacteria multiply at different rates. One week may be enough for one type of bacteria to dominate, but given more time, a new species may come to dominate the sample. The change in bacteria populations corresponds to the change in smell over time.

Table I: 100-fold serial dilutions of results

10^3 + nutrient 10^5 + nutrient !0^7 + nutrient 10^9 + nutrient 10^3 + nutrient & tet 10^5 + nutrient & tet 10^7 + nutrient & tet 10^9 + nutrient & tet

Do you see any differences in the colony types between the plates with vs without antibiotic?

The colony types with antibiotic were mostly spindle-shaped and had very small colonies. The ones without had numerous amounts of orange and yellow round colonies.

What does this indicate?

The specific types of bacteria present only in the treated agar are antibiotic resistant.

What is the effect of tetracycline on the total number of bacteria? Fungi?

tetracycline does not have any effect on fungi. It is effective on most but not all bacteria.

How many species of bacteria are unaffected by tetracycline? 

photos tba

Lab 4: Plantae and Fungi

Procedure 1: plant samples from transect

Name/Description location vascularization leaves/special charactaristics seeds/flowers/reproduction

Angiosperm, found under rose bush xylem/phloem round leaf with pointed tip rose flowers (dicot) Rosa(leaf)

Angiosperm, found under rose bush none frozen flower from rosebush rose flowers (dicot) Rosa(frozen bud)

Angiosperm, found in mulch/leaflitter xylem/phloem 6 lobes, spines acorn seeds (dicot) Quercus(oak leaf)

Angiosperm, found in mulch/leaflitter none seed for black oak tree acorn seeds (dicot) Quercus(acorn)

Angiosperm, found on ground vessels throughout blade-like leaves, (monocot) Agrostis(grass)

Procedure 2:

Vascularization of Oak Tree: Oak trees have extensive root systems which absorb water and nutrients. They are absorbed up the trunk (Xylem) to branches which grow leaves (phloem). Protective cuticle, stoma which allow for gas exchange.

Vascularization of Grass: long, thin chlorophyl-filled blades sprout from the ground. Grass has veins which go down the length of the stem and converge at the base, which leads down to the root. The root absorbs nutrients from the ground and intertwines with the grass plant next to it, creating a vast web of grass plant leaves (lawn.)

Vascularization of Rose bush: Small round leaves absorb sunlight and veins within the leaves carry nutrients into the plant.

Procedure 3:

Oak Tree Leaf: Oak tree leaf is about 8 cm in length, with veins down the center and six "petals" which extend out from the center vein, each posessing a connecting vein. The base of the leaf connects to the branch. Topside has protective cuticle, underside has stoma pores for gas exchange.

Rose Bush Leaf:about 4 cm in length, round and egg-shaped at the connecting end converging to a point at the opposite. Has veins down the center of the leaf, also straight outward-branching veins along the length of the leaf. Also has cuticle upper side and stoma on underside.

Grass Leaf:Very long, thin blade (6 cm in length by .25 cm in width) green from chlorophyll. Has an upper side and underside with cuticle and stoma respectively.

Procedure 4:



Grass: monocot

Procedure 5: 

What are Fungi Sporangia and why are they important? Fungi sporangia are the reproductive stage of fungi. They are important because they produce haploid spores during the stage of meiosis.

Fungi example: [img]

Lab 5: Invertebrates

Procedure I: observing Acoelomates, Pseudocoelomates, and Coelomates

Planaria: flat, dark slug-like organisms which have an ectoderm, endoderm, and mesoderm. They glide fluidly through the water by beating cilia (ventral side) they do not have a body cavity, and do not seem to be extremely maneuverable.

Nematode:round worms with a tubular digestive system.Have exoskeletons, move in a whip-like manner.

Annelida:earthworms have a coelem and are able to move by contracting and expanding their body segments (peristalsis).

Procedure 2: analyzing invertebrates collected with the Berlese funnel

[img] [img] [img]

The Berlese funnels yeilded several different species of invertebrates, including a 10 mm centipede, transluscent 1 mm ground spider (arachnid), and several brown beetles (springtails) of about 2 mm in length (insect). Sizes ranged from <1mm spider to 10 mm centipede, with the most prevalent invertibrate being the springtail beetle.

Procedure 3: Vertibrates and Niches

five vertibrates which inhabit the transect:

squirrel (Sciuridae) Eastern Grey Tree Squirrel/ Black Squirrel. Eats seeds and nuts from nearby trees, takes leaf litter for nest building.

rat (Rattus norvegicus) Brown Rat. eats fast-food litter.

blue jay:(Cyanocitta cristata) Bluejay. Preys on bird eggs and insects.

House Sparrow: (Passer domesticus) Sparrow. Feeds on fast-food litter from nearby cafeteria, seeds and small insects. Sometimes prey to Red-Tailed Hawk, eggs are sometimes prey to Bluejay.

Red-Tailed Hawk: (Buteo jamaicensis)Hawk. Preys on prevalent squirrels and rats in the transect,also occasionally preys on smaller birds and eggs.

Food web [img]

Lab 6: Embryology & Zebrafish Development

Procedure 1: starfish development

The starfish embryo exhibited radial cleavage, with cells splitting evenly outwards. At the point of the gastrula stage, the embryo starts to look like an egg with yolk, exhibiting an outer and inner sphere.

Procedure 2: frog development

This embryo exhibits bilateral holoblastic cleavage. It is not symmetrical like the early stages of starfish. [image]

Procedure 3: chick development

A 72-hour-old fertilized egg was cracked open and placed into a bowl for observation. They had the appearance of normal unfertilized eggs used in cooking, with the exception of a large pale white circle on the yolk, (germinal disc) presumably where cleavage had begun.

Table 1 Summarized: comparison of embryological features of developing starfish, frog, chick, and human.

relative egg size: Starfish: expel vast quantities of eggs into the water. These eggs are relatively extremely small.

               Frog:Frog eggs are relatively large compared to the size of the adult frog laying them.
               Chicken:A chicken egg is extremely large compared to the chicken laying them.
               Human:a human egg is .1 um in diameter, relatively the smallest of the four species.

fertilization: Starfish:Starfish disperse eggs or sperm into seawater; reproduce externally (external fertilization)

               Frog:Frogs reproduce sexually. (external fertilization)
               Chicken:Chickens reproduce sexually.
               Human:Humans reproduce sexually.

amount of yolk (holo/mero): Starfish:divide into distinct and separate cells (holoblastic)

               Frog:divide into distinct and separate cells (holoblastic)
               Chicken:uneven amounts of yolk (meroblastically)
               Human:lopsided/uneven amount of yolk (holoblastic)

distribution of yolk (iso/telo): Starfish:small amount evenly distributed. (isolethical)

               Frog:yolk in vegetal hemisphere (telolethical)
               Chicken:yolk in vegetal hemisphere (telolethical)
               Human:evenly distributed yolk(isolethical)

Blastulation: Starfish:blastocels and blastomeres present, hollow sphere

               Frog:asymmetrical blastula
               Chicken:blastodisk forms, separates, and forms blastocoel.

Gastrulation: Starfish:movement of cells into blastula to create layered sphere

               Frog:uneven growth of cells create blastopore. 
               Chicken:cells form linearly to make a primitive streak, which spread out and form mesoderm.

Larval Stage: Starfish:motile

               Frog:neural tube and organs- larval form is tadpole.
               Chicken:parental care
               Human:parental care

Waste Disposal: Starfish:disperses

               Frog:yolk plug
               Chicken:special pouch near the yolk

Protection: Starfish:starfish produce many eggs which float in the ocean, presumably not all are eaten by predators. Larval stage is motile.

               Frog:frog eggs have a gel-layer which protects the egg from the outer elements. Egg is suspended in a water environment.
               Chicken:Chicken eggs have a hard shell covering which contains the egg yolk, embryo and albumen.(calcium carbonate shell)
               Human:The human embryo remains inside the mother until birth, and is protected inside the uterus

Zebrafish Experiment:

Original procedure outline and amendments:

20 healthy, translucent zebrafish eggs were placed in a control water petri dish. 44 healthy zebrafish eggs were placed in an experimental dish containing 20 Mg/L caffeinated water, labelled Caffeine I. This was done in case the concentration of caffeine resulted in high mortality of the fish within the first 72 hours.

After 72 hours, the eggs for the Control dish hatched and all but one egg in the Caffeine dish hatched. 20 fish were removed from the experimental dish into a new dish containing control water. This new dish was labelled Caffeine II. This was to see if only early gestational exposure to caffeine affects the later development of the fish. This aspect of the experiment roughly parallels from a medical viewpoint a mother who exposes herself to caffeine while pregnant causing or not causing problems for the child’s development, even if after birth the child does not ingest any more caffeine.