BIO LAB EXAM

axial skeleton

Portion of the skeletal system that consists of the skull, rib cage, and vertebral column

credible literature

- primary (peer reviewed, scientists wrote it, scientific papers)
- secondary (peer reviews, experts compile from primary, literature reviews)
- tertiary (fact checked, use primary and secondary, textbooks)
- grey (not peer reviews, published outside of commercial journal, reports)
- web (not peer reviewed, wikipedia)

scientific paper

abstract - summary of article
Introduction - Background, Objectives, Hypothesis, Predictions, Relevance
Methods - allow reader to duplicate procedure
results - describe outcome of study (trends/tables) NO interpertation
discussion - interpret results, main findings, compare, significance, limitations
cite

citation

Last name First Name Initial. Year. Title of Article. Journal Name. Volume number(issue number): page numbers.

aseptic technique

- tie back hair
- clean hands, disinfect, use soap
- use Bunsen burner to sterilize
- hold container lid at 45 degree angle when opening
- do not breath on culture
- dispose of contaminated materials

4X objective lens: 1 epu \=
10X objective lens: 1 epu \=
40X objective lens: 1 epu \=

\= 25 μm
\= 10 μm
\= 2.5 μm

Magnification calculation

size of drawing/size of object - calculated from epe

mm to μm

multiplying your measurement by [1000 μm / 1 mm]

μm to mm

by multiplying your measurement by [1 mm / 1000 μm] (the same as dividing by 1000)

Compound vs. Dissecting Microscope

Compound Microscopes have greater magnifications, but lower resolutions

Dissecting microscopes have lower magnifications, but greater resolutions, more versatile

why is important to center the object in the field of view before switching to a higher magnification in a compound microscope?

because the FOV becomes smaller and the depth of field becomes shallower so you need to center it

Kaz was streaking a plate for a demonstration in lab, but their plate was contaminated. Based on their procedure below, where did they go wrong?

They opened the petri dish and placed the lid upside-down on the clean bench

What are the units on the ocular micrometer of the compound microscopes?

eye-piece units (epu)

compound microscope

a light microscope that uses more than one lens to magnify an object

how does the level of magnification affect the brightness of the field of view in a compound microscope

- lower magnifications FOV is wider so object appears brighter and sharper
- higher magnification FOV is smaller so object appears dimmer and blurrier

dissecting microscope

light microscope used for low magnifications and larger objects

in what situations would it be helpful to use the transmitted light instead of the direct light in a dissecting microscope?

- specimen is translucent
- small, solid objects for fine detail
- live organisms
- reflective or shiny objects to reduce glare

does the level of magnification affect which type of light is best for viewing your specimen?

- at lower magnifications direct light (wider FOV)
- at higher magnifications transmitted light (greater contrast)

Scientists depict evolutionary relationships using what kind of diagram?

Phylogenetic Tree

Nodes

place on a phylogenetic tree where the branches divide

Clades

groups that include an ancestral species and all of its descendants

Terminal taxa

last part of the branches, not containing more descendants

In phylogenetics, a close relative of the study group is selected as the \__________

Outgroup

What are the four mechanisms of evolution?

Gene flow, mutation, genetic drift, and natural selection

Terminal nodes

a location on a phylogenetic tree where the branches end

Sympatric speciation

occurs when there is a non-geographical reproductive barrier.
- sexual selection
- habitat differentiation

Allopatric speciation

occurs when there is a geographical barrier that separates populations.
- mountain range
- river

on table 2-4, why do the observed number of base changes differ from the expected number of base changes

due to random variation

on table 2-4 how do the observed number of base changes differ from the actual number of base changes

actual is higher due to convergence or evolution

molecular clock hypothesis

-Mutations accumulate at a clocklike rate
-Use mutations to tell time
-Estimate how long ago ancestors branched off by counting the number of mutations
-Different stretches of DNA mutate at different times
-Pseudogenes and repetitive sequences acquire mutations faster because they do not lead to a loss in fitness
-Useful in tracking disease origins
- the more mutations the longer its been since they've diverged from a common ancestor

Null and Alternative Hypothesis

Ho \= any differences in results are due to natural variation, no correlation between experiment group and treatment
Ha \= any differences in results due to treatment, there is a correlation between experiment group and treatment

degrees of freedom

(n1 - 1) + (n2 - 1)
A parameter based on your sample size that helps determine the critical value for your test.

If you have a lot of variance (s2) or variation in your data, then

your data points are very spread out, and it makes for a lot of noise

If the means (x̅) of your two populations are very close together, then

then your signal is weak and it may be difficult to find a significant result

t-test

A t-test is used to determine if two groups are "different enough" to be considered different populations (or distributions), or if they are really part of a larger population that you just didn't sample enough of.
If the two groups in our experiment are from the same population, they would form a roughly normal distribution when pooled together. If phosphate has a significant impact on the growth of the seedings, then those are considered to be a different population, and should form two separate distributions.

if the calculated t-stat is larger than the t-critical value, what does this mean?

the difference between the means of the two populations is statistically significant and we can reject null hypothesis.
if it is smaller or equal then we cannot reject the null hypothesis

if you find a p-value that is lower than your alpha level, what does this mean for your experimental hypothesis?

The Ha is true and results of the experiment are statistically significant

alternation of generations

life cycle that has two alternating phases—a haploid (N) phase and diploid (2N) phase

In land plants, \__________ results in the production of haploid spores.

meiosis

Spores

are single cells that germinate and develop into multicellular plants that produce the sex cells or gametes

how do the observed v

fern life cycle

1). Zygote develops into leafy fern plant.
2) the sporophyte.
3) Spores are released from spore cases and grow into gametophytes. Each gametophyte has both male and female structures.
4) Sperm swim to another gametophyte to fertilize eggs.

archegonia

Female reproductive part of a nonvascular plant

Antheridia

Structures in plants that produce male gametes

The sperm and egg join to form a zygote, which initiates the

diploid phase of the life cycle, the sporophyte.

The \_______________ is the visibly dominant generation in ferns and seed plants, while the \________________ is very small and not easily seen.

sporophyte, gametophyte

Ceratopteris richardii

homosporous fern that has two distinct phases to its life cycle, a simple haploid gametophyte, and a more complex, diploid sporophyte.
Developed two different types of gametophytes from the spores - hermaphroditic gametophytes, which have both archegonia and antheridia, and male gametophytes which have only antheridia. The archegonia produce eggs and the antheridia produce sperm.

A common theme throughout the Kingdom Plantae is

convergent evolution - an independent evolution of similar adaptations.

reasons for the fern's dependency on water

- Water signals the release of chemicals to attract sperm\
- Water causes the archegonia to open
- Water allows sperm to swim to the egg

descriptive statistic

mean, median, mode and standard deviation, and number of scores for each treatment

Sporophyte

Diploid, or spore-producing, phase of an organism. Makes haploid spores by meiosis.

Gametophyte

bear the male and female gametes, and also serve as the site for fertilization

adaptations to land

Vascular Tissue
Roots
Internal Gametophytes
Seed-production
Seed coats

three major groups of land plants

Non-vascular plants, seedless vascular plants, and vascular seed plants

t-value

The estimate of the difference between the groups relative to the variability of the scores in the groups

A large difference in means and small variances results in

largest t-value

The lower your p-value, the more likely it is that

Alternative hypothesis is true

alpha level

The threshold P-value that determines when we reject a null hypothesis

critical value

A value from a standardized table that is compared to the test statistic to determine significance.

p-value

The probability of results of the experiment being attributed to chance.

species' ecological niche

No two species can occupy the same niche, but niches can overlap as long as there are differences between them.

interspecific competition

competition between members of different species

specialists

species that have narrow niches

generalists

species with broad niches

trophic level

- producers
- primary consumers (herbivores)
- secondary consumers
-tertiary consumers
- decomposers

Microhabitat

A very small specialized habitat, such as the space under a rock.

why aren't the proportions of producers and consumers equal?

because only 10% of energy is passed down, so there will be more producers then consumers

what happens if the top predator dies off

food chain crashes, population of top predators prey will increase

habitat selection

the process by which organisms actively select habitats in which to live
Habitat selection behaviour reflects an organism's microhabitat

niche

different from its habitat. The habitat is where a species is found, while its ecological niche is the exact role it plays in the community - how it utilizes all of the biotic and abiotic resources available.
- what it eats and where, its range of livable temperature / humidity / salinity, and the time of day that it is active. The niche that an organism fills is very specific, and no two species can occupy the same niche in a community. Niches can, however, overlap, as long as there are some differences between them--this reduces competition

What is the evolutionary advantage of producing compounds to inhibit the growth of bacteria?

To reduce competition in the surrounding soil

absorptive heterotrophy

Fungi digest food outside their bodies by secreting digestive enzymes to break down large food molecules, then absorbing the breakdown products.

All fungal cells have a rigid wall made of

chitin which is external to the plasma membrane

Parts of a mushroom

ingestive heterotrophy

obtain energy and organic molecules by ingesting other organisms

hyphae

The basic building blocks of the fungal body are tubular filaments

mycelium

densely branched network of the hyphae

fruiting bodies

The reproductive structure of a fungus that contains many hyphae and produces spores

life cycle of fungi

Basidiomycetes life cycle

club fungi, fruiting body that produces spores

Ascomycetes

sac fungi

by what cellular process are spores produced? How are they dispersed?

meiosis, they are ejected and dispersed by the wind

How is the life cycle of a fungus similar to that of a land plant? how is it different?

- both have sexual reproductive stage
- both undergo meiosis to produce haploid spores

- fungi are heterotrophic
- fungi have 2 different mating types, plants have both parts on the same plant

why are genera like Penicillium considered to be imperfect fungi? Why do you think they are so successful at breaking down food?

They lack a known sexual reproduction stage
They are successful at breaking down food because they grow fast, have wide distribution, are able to break down complex molecules.

Ectomycorrhizae

mycorrhizae in which the fungal hyphae do not penetrate the root cells of the plant

arbuscular mycorrhizae

microscopic fungal hyphae extend into the root

Fungi are heterotrophs like animals, but they do not eat food in the same way. Instead,

they absorb nutrients from the environment outside of its body. Many fungi will secrete enzymes into the environment which break down complex molecules into smaller ones that the fungi can absorb and use. Other fungi will use enzymes to penetrate cell walls and absorb nutrients.

in lichen, what adaptations does the fungus have to have to allow the photosynthetic partner better access to sunlight?

- thallus morphology
- pigments
- photobiont selection

How does mycorrhizae blur the lines between species and individuals between species?

- network formation, it connects species
- horizontal gene transfer, gives ability to transfer genetic information
- coevolution, specificity between plant and fungus spores

Lichen

- improve nutrient cycling
- stabalize soil
- in return get protection from UV

Bioindicator

a species that is especially sensitive to ecological change and thus can serve as an indicator of environmental conditions

soredia

clusters of algal cells and mycelia that allow lichens to propagate

Mycorrhizae

- increase nutrient uptake
- improve water uptake
- disease resistance to plant
- in return get carbs and sugar

body plan

a set of morphological and developmental traits that characterize the anatomical organization of an animal. Body symmetry, tissues, body cavities and mode of development (protostome development or deuterostome development) represent aspects of an animal's body plan.

Eumatazoa

Eumetazoans are a diverse group of animals that includes all animals with true tissues. They are divided into two major clades: Radiata and Bilateria.

Radiata clade

- includes the phyla Cnidaria and Ctenophora.
- Cnidarians have radial symmetry and include jellyfish, sea anemones, and corals.
- Ctenophores, or comb jellies, are also radially symmetric and have a unique locomotion mechanism that involves rows of cilia.

Bilateria clade

Lophotrochozoa, Ecdysozoa, and Deuterostomia

Lophotrochozoa

- protosomes
- horseshoe-shaped feeding organ
- trochophore larva
- platyhelminthes (flatworms)
- molluscua (snails, clams, squid, and octopuses)
- annelidia (segmented worms)

Ecdysozoa

- protosomes
- undergo molting to grow
- Arthropods (insects, crustaceans, and arachnids)
- Nematodes (earthworms)

Deuterostomia

- deuterosomes
- radial cleavage (despite being bilateria)-echinodermata (starfish, sea urchins, and sea cucumbers)
- chordata (vertabrates)
- hemichordata (Acorn worms)