Lab Practical Prep (Natural Selection & Microscopes and Prokaryote Diversity)

Personal Protective Equipment (PPE)

Full-sleeved, mid thigh lab coat, nitrile/latex gloves, safety goggles/glasses

Formula for number of allele in surviving population

Ex. Number of B alleles = [# of black mice (BB) x2] + [# of brown mice (Bb) x 1]

Black fur allele (mice)

BB

Brown fur allele (mice)

Bb

White fur allele (mice)

bb

Frequency of allele formula

Frequency of (desired allele) = number of (desired allele)/total alleles

phenotype

observable traits expressed by an organism

genotype

underlying genetic makeup consisting of both visible and non-expressed allele(s) of an organism

allele

gene variation that arise by mutation and exist the some relative location on homologous chromosomes, influencing traits.

evolution

the process of gradual change in population over time/change in allele frequency over time

natural selection

reproduction of individuals with favorable genetic traits that survive environment change because of those traits, leading to evolutionary change

adaptation

heritable traits that enhance an organism's ability to survive and reproduce in its environment.

fitness

reproductive success of an individual relative to the rest of the population

Genetic variation

difference in DNA between individuals in the same species

Hardy-Weinberg Principle

Allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences

Hardy-Weinberg Equation

p²+2pq+q²=1

Ocular Lens

allows individual to observe specimen; has a magnification of 10x

rotating nosepiece

rotates to change objective lens

Arm

backbone of microscope where one carries the microscope

mechanical stage

holds slide

stage

where the specimen is placed

objective lens

has a certain magnification to observe the specimen

Four types of objective lenses

4x, 10x, 40x, 100x

Total magnification

10x multiplied by objective lens magnification equal this:

condenser

focuses light on specimen

Iris diaphragm

controls amount of light passing through the condensor

light source

provides light to specimen

coarse adjustment knob

makes large adjustments to focus specimen by raising stage

fine adjustment knob

makes small adjustments to focus specimen, used with 40x and 100x lenses

light intensity control knob

adjusts brightness of illumination

stage control knobs

moves the stage horizontally or back and forth vertically

base

bottom of the microscope

prokaryotes

in the domains bacteria and archaea; single-celled, no nucleus, no membrane bound organelles, much smaller than eukaryotes, single circular DNA, divide by binary fission, simple flagella, oxygenic and anoxygenic photosynthesis, can be photoautrophic up to chemoheterotropic

coccus (spherical), spirillum (spiral), bacillus (rod)

three shapes of bacteria

colony

visible mass of microorganisms all originating from a single mother cell

Lactobacillus

Rod-shaped bacteria, nonmotile, chemoheterotroph, found in yogurt, helps partially digest proteins and milk solids

Streptococcus

round-shaped bacteria, nonmotile, chemoheterotroph, found in yogurt, helps partially digest proteins and milk solids, also includes some notorious pathogens

Rhodospirillum rubum

purple, non-sulfur bacteria, bacteriochlorophyll captures light energy, photosynthesize without producing oxygen. Colorless in high oxygen levels and purple-red when oxygen levels are low.

Doman: Bacteria

Shape: spirillum

Movement: Motile-flagellum

Metabolic features: photoautotroph (can also perform fermentation)

Oscillatoria

Domain: Bacteria

Phylum: Cyanobacteria

Shape: filament/bacillus

Movement: oscillating/whip-like motion

Metabolic: Autotrophic

Gloeocapsa

cells held together by secreted gelatinous mixture

Domain: Bacteria
Phylum: Cyanobacteria

Shape: Coccus

Movement: non-motile

Metabolic: Autotrophic

Form colonies

Anabaena

Contains heterocysts

Domain: Bacteria

Shape: Coccus but forms filaments

Movement: non-motile

Metabolic features: autotrophic

Heterocysts

Enlarged cells that have thickened cell walls and fix nitrogen

Extremophile

an organism that can survive and thrive in extreme environmental conditions

Halobacterium salinarum

Aerobic heterotrophs when oxygen is present, but phototrophs most of the time due to lack of oxygen. Use bacteriorhodopsin to generate ATP. Halophile

Domain: Archaea
Shape: Bacillus

Movement: Motile-flagellum

Metabolic features: heterotrophic in oxygen rich environments, phototrophic in low oxygen environments

Azolla and Anabaena

symbiotic mutualistic relationship

One is a plant, photosynthetic other is a bacteria also photosynthetic

(Plant) provides an enclosed environment for (bacteria) within its leaves. In return, (bacteria) sequesters nitrogen directly from the atmosphere which then becomes available for (plants)'s growth, freeing it from the soil that is needed by most other land plants for their nitrogen fertilization.