bio lab 3 week 8 Flashcards
What can living organisms be
Unicellular or multicellular
Name the 2 types of cells
Prokaryotic and eukaryotic
Describe prokaryotic cells
No nucleus, no membrane bound organelles
2 domains = bacteria and archaea
What are archaea related to
Archaea is more closely related to eukaryotic cells
What are bacteria
Prokaryotic
Name the 2 things can bacteria be
Pathogenic
Non pathogenic
What are most bacteria
Saprophytic (function as decomposer)
What are saprophytic bacteria
Heterotrophic
Describe the purpose of saprophytic bacteria
Secrete digestive enzymes into environment which breakdown organic macromolecules into organic monomers and inorganic molecules
What are some bacteria
Producers, autotrophic
Describe the purpose of autotrophic bacteria
Synthesize organic molecules from inorganic molecules using energy from sunlight (photosynthetic) or from oxidation reduction reactions (chemosynthetic)
Describe cyanobacteria
Photosynthetic bacteria
Found in water environments
Some species produce toxins and create problems in lakes
What are bacteria required for
Nitrogen cycle
What do bacteria do in nitrogen cycle
Carry out nitrogen fixation
Atmospheric nitrogen N2 is converted into inorganic nitrogen for growth of plants
Describe cell wall of bacteria
Made of peptidogylcan
Describe how bacteria can be classified
Shape Bacilli (rod shaped) Cocci (spherical) Spirilla (spiral shaped) Gram stain Gram positive (purple) Gram negative (pink) because of differences in composition of their cell wall
What is the zone of inhibition
No growth zone of E coli
Describe eukaryotic cells
Domain = eukarya
Define protists
Diverse group of distantly related eukaryotes (not plants, animals or fungi)
What are most protists
Unicellular
Most from colonies
Some are multicellular
What are protists classified as
Plant like (algae) Animal like (protozoan) Fungal like
Name two examples of animal like protists
Amoeba
Paramecium
Describe amoeba
Unicellular
Forms pseudopods by cytoplasmic streaming to move and engulf prey (phagocytosis)
Describe paramecium
Unicellular
Uses cilia for movement
What are protists believed ro be
Ancestors of plants, fungi and animals
What are protists in relation to the food chain
Important food source in aquatic food chains (phytoplankton and zooplankton)
What are cilia
Furry hair part on outside
Describe chlamydomonas
Unicellular
Oval shape
Uses 2 flagella at anterior end for movement
Describe volvox
Colonial organism showing division of labour
Cells that are arranged in a hollow sphere surrounding daughter colonies (mode of reproduction)
Describe spirogyra
Multicellular
Filamentous green algae with a spiral shaped chloroplast
Describe kingdom fungi
Non motile organisms with rigid cell walls made of chitin
What are multicellular fungi composed of
Masses of filamentous cells which provide area for absorption
What are fungi
Absorptive heterotrophs
What are fungi classified as
Decomposers (saprobes)
Parasites
Mutualistic (lichens)
What is lichens
Variety of colours and forms
Describe fungi mutualistic symbiosis
2 different organisms = photosynthetic autotroph and a fungus
Fungus receives nutrients produced by autotroph through photosynthesis
Autotroph receives minerals absorbed by fungus
What is kingdom plantae
Terrestrial plants that have simple requirements as green algae
Name the simple requirements for kingdom plantae
Light CO2 O2 H2O Some minerals
Name adaptations for plants
Evolved vascular tissues in the form of roots to transport nutrients from soil
Pollen and seeds evolved for fertilization and protection/dispersion of the embryo
What is the life cycle of all terrestrial plants
Alternation of generations
Describe characteristics of phylum bryophyta (mosses)
Small land plants
No vascular tissue
Keep all parts of plant body close to moist soil
Reproduce sexually by flagellated sperm cells swimming to egg cells
Gametophyte (haploid) is dominant and the spore producing sporophyte (diploid) is dependant on the gametophyte
Describe characteristics of phylum pterophyta (ferns)
Seedless plants
Grow taller than bryophytes because of vascular tissue in the sporophyte
Limited to moist environments
Flagellated sperms must swim to egg cells to achieve fertilization in sexual reproduction
Gametophyte produces a fiddlehead that develops into sporophyte which is dominant
Describe characteristics of phylum coniferophyta (gymnosperms)
Conifers (pines, firs, spruces, cedars…)
Gymnosperm = naked seed
Have male and female cones
Most are evergreens that retain leaves year round
Needle shaped leaves are adapted to dry and cold conditions
Gymnosperms have seed and pollen
Sporophyte stage is dominant
Describe characteristics of phylum angiophyta (angiosperms)
Flowering plants
Most numerous, diverse and widespread of the terrestrial plants
Plant or tree we recognize = mature sporophyte (multicellular diploid)
Gametophytes are housed within flower (specialized reproductive structure in angiosperms)
Have seed and pollen
Additional adaptations of flowers and fruit (protects seeds)
Flower is often colourful to advertise the flowers to pollinators (birds and insects)
Name 3 main parts of a flower
Modified leaves
Stamen (male reproductive organ)
Carpel/pistil (female reproductive organ)
Describe components of the modified leaves of a flower
Sepal = enclose and protect the flower bud before opening Petal = colourful and advertise to pollinators
Describe components of the stamen of a flower
Anther = pollen sac of the flower which produces pollen grains containing male gamete Filament = supports the anther
Describe components of the carpel/pistil of a flower 3
Stigma = sticky part of the carpel that traps pollen grains Style = stalk of carpel Ovary = part of carpel in which egg containing ovules develop, develops into fruit
Name and describe the 3 types of roots
Taproot = thick main root with lateral roots growing from it Fibrous = no central root, consists of mass of thick roots Adventitious = grows from the stem or any organ other than the root
Name the parts of a root (6)
Epidermis Cortex Endodermis Pericycle Xylem Phloem
Describe the epidermis
Protective outer layer, 1-3 cell layers thick
Describe the cortex
Stores starch, large cells between vascular bundle and epidermis
Describe the endodermis
Single layer of smaller cells just inside cortex, cell walls are thickened, controls entry of water into vascular bundle
Describe the pericycle
Have ability to divide and give rise to lateral roots, single layer of cells just inside endodermis
Describe the xylem
Conduct water and minerals throughout plant and provide support, large thick walled dead cells in centre, x shaped
Describe the phloem
Transports organic food throughout plant, small, compact, live cells between arms of xylem
Describe the stem
Part of plant above ground, upright, bears leaves
Supports leaves and flowers of the plant
Some stems are sites of food storage
Describe leaf structure
Blade = broad, flat part of leaf
Petiole = thin stem like part that attaches the blade to the stem (some leaves lack petioles and have the blades directly attached to the stem = sessile leaves)
Venation present = veins are vascular bundles seen in longitudinal sections
Leaves can be simple (single leaf) or compound (leaflets)
Describe the 2 types of leaf venation
Some leaves have parallel venation
Others have net venation (palmate or pinnate)
Name the parts of a leaf (7)
Upper epidermis Palisade mesophyll Spongy mesophyll Lower epidermis Guard cells Stoma Vascular bundle (vein)
Describe the upper epidermis
Top layer of cells coated with waxy cuticle
Describe the palisade mesophyll
Cylindrically shaped cells arranged in layers just below the upper epidermis, main area of photosynthesis, many chloroplasts
Describe the spongy mesophyll
Irregularly shaped cells just below the palisade mesophyll with many air spaces between them
Describe the lower epidermis
Bottom layer of cells
Describe the guard cells
Controls opening and closing of stomata
Describe the stoma
Gas exchange for photosynthesis/cellular respiration and water evaporation
Describe the vascular bundle
Thick walled xylem cells and small phloem cells, transportation of water, minerals and food throughout plants
Name and briefly describe the 3 categories of adapted leaves
Syringa = mesophyte (not too wet, not too dry)
Nerium, oleander = xerophyte (dry)
Nymphea = hydrophyte (wet, floats on water)
Describe syringa (mesophyte)
Normal cuticle
One layer of epidermis cells
No large spaces in spongy mesophyll
Stomata in lower epidermis not in pits lined with hair
Describe nerium/oleander (xerophyte)
Very thick cuticle
More than one layer of epidermal cells
Stomata are in sheltered pits lined by hairs
Palisade mesophyll cells are smaller and less numerous
Describe nymphea (hydrophyte)
Very thin cuticle
Bigger palisade layer and epidermal cells many contain chloroplasts
Stomata in upper epidermis
Very large air chambers in spongy mesophyll to float
Describe 3 steps to wet mount procedure
Place specimen in a drop of water on the slide
Gently lower coverslip to avoid formation of air bubbles
Dry the underside of slip before putting it on the stage (wet slide will stick to stage and make it hard to move it around)
