Practical I :P Flashcards
Heterozygous
Having 2 different alleles of a particle gene / genes
Homozygous dominant
A genotype where an individual inherits 2 copies of a dominant gene
Homozygous recessive
2 copies of the same recessive allele
5 assumptions of the Hardy-Weinberg Equilibrium?
- no mutations (no new alleles are generated)
- random mating (organisms mate randomly with no preference)
- no gene flow (no individuals / gametes enter or exit a population)
- very large population size (effectively infinite in size)
- no natural selection (all alleles confer equal fitness)
How to calculate allele and genotypic frequencies of dominant , recessive, and heterozygous alleles?
(Search up and practice)
P+q = 1 (alleles)
P^2+2pq+q^2 = 1 (genotypes)
What are the 3 domains of life?
Domain bacteria, archaea, & eukarya
Compare & Contrast Prokaryotic and Eukaryotic Cells (size, division, chromosomes…)
Pros:
- cell represents the entire organism
- ribosomes & DNA, but no membrane-bound organelles
- predominant biomass on the planet
Eus:
- larger & more complex organisms as well as microorganisms
- well defined nuclear membrane and numerous membrane bound organelles
3 basic shapes of prokaryotes, flagella, and peptidoglycan
- cocci (spherical)
- bacilli (rod shaped)
- spirilli (spiral shaped)
(Others)
Chains - strep
Clusters - staph
What are the steps of the Gram staining procedure?
Gram stain - tool for identifying specific bacteria based on the differences in cell walls
- Crystal violet (20 secs)
- Rinse with water (2 secs)
- Cover with gram’s iodine (1 min)
- Decolonize for 5 - 15 secs
- Rinse w water for 2 secs
- Counterstain w Safranin for 20 secs
- Rinse with water for 2 seconds
- Blot dry with bibulous paper
What’s the difference between gram negative and gram positive?
Gram +
- bacteria have simpler cell walls, with large amounts of peptidoglycan
- thick peptidoglycan layer
Gram -
- bacteria have more complex cell walls and less peptidoglycan
Interpret bacterial sensitivity assays
antimicrobial
- chemical that inhibits / kills microbes
- antibiotics (fight bacterial infections) & disinfectants
Disinfectants
- used to control bacterial growth on inanimate objects
- not suitable because of their toxicity to living tissue
Antiseptics
- used on living tissues (ie skin)
- Hydrogen peroxide, rubbing alcohol, mouthwash, iodine
Cell wall (peptidoglycan) breakdown & inhibition of protein synthesis
- gram staining
Kirby-Bauer disc diffusion technique
- used to determine antimicrobial activity of chemical compound
- lack of microbial growth indicate zones of inhibition
What is the aseptic technique?
Free from contamination from microorganisms
~ ex: wiping bench with disinfectant alcohol, using sterile loops when transferring cultures, flaming culture bottle necks to prevent contamination, washing hands thoroughly
Protista: Protozoa (compare locomotion of each)
Protozoans: single cell heterotrophs, prey upon other bacteria/protozoans, phagocytosis and absorption of nutrients
Ameboid protozoans: phylum rhizopoda
- pseudopods to move and feed
Ciliated protists: phylum ciliophora
- numerous short cilia to beat prey to gullet & to move
Rhizopoda
Amoeba, phagocytosis, pseudopods, contractile vacuole
Ciliophora
Paramecium, cilia, contractile vacuole, micro and macro nucleus
Macronucleus
- controls everyday cellular functions
Micronucleus
- regulate sexual reproduction
Euglenoids
- Phylum Euglenophyta
- single celled algae
- chloroplasts
- heterotrophic / photosynthetic-heterotrophs
- animal like flagella
- light sensitivity eyespot
- not a rigid cell wall, flexible membrane instead
Protista Algae
- phylum chlorophyta
- unicellular, colonial, filamentous, & multicellular forms
- related to photosynthetic plants
- cell wall structure , photosynthetic pigments & metabolic pathways, starch as storage form
Phylum Bacillariophyta
- diatoms
- 1/2 of the primary productivity, 1/4 of O2
- most numerous after plants
- possess chlorophyll, but yellow due to carotenoids & xanthophylls (golden algae)
- diatomaceous earth
Chlorophyta : the 3 types of algal cellular organization?
Chlamydomonas, volvox, Spirogyra
Fungi (structure, mode of reproduction, phyla + example of each)
- mostly decomposers
- break down organic matter and recycle the nutrients back into the ecosystem
- eukaryotic heterotrophs (like animals)
- do not ingest their foods (unlike animals) ; secrete hydrolytic enzymes to break down complex organic molecules
- cell walls contain chitin
- cannot move except by growth or dispersal of their spores
- life cycles are complex; can have both diploid and haploid stages
Phyla:
- chytridiomycota ex.
- zygomycota ex. Rhizopus
- glomeromycota ex.
- ascomycota ex. Yeasts
- basidiomycita ex.
Hyphae , Spore , Mycelium (definitions)
Hyphae - branched filaments of the fungus
Karyogamy , Plasmogamy , & heterokarogamy role of meiosis and mitosis (definitions)
Zygomycota
Mating types, sporanium, gametangia, zygosporangium, rhizopus
Ascomycota
Ascus, conidia, yeast (sacchromyces) vs mold (penicillin)
