Bio 1102 Exam 2

• - Domain: Eukarya (multicellular)
• - Kingdom: Plantae
• - Autotrophs: produce own food/nutrients
• - Cell walls made of cellulose

Flowering plants

• - Located underground
•       - anchor and support
• -Absorbs water and minerals

• - Only in angiosperms (flowering plants)
• - Consists of stem and leaves
• - Stems role: transports water and minerals from the roots to the leaves. Also transports the products of photosynthesis. 
• - Leaves role: Photosynthesis
•         - Water, Carbon Dioxide, Sunlight

• - Main axis of the plant (angiosperms) 
• - Supports the leaves
• - Contains vascular tissues

• - Major part of the plant that carries out photosynthesis
• - Waxy cuticle that reduces gas exchange
• - Contain Guard Cells (epidermal cells with chloraplasts) and Stomata (small pore in leaf epidermis)
• - Usually Broad and flat
•       - Blade: Wide portion of leaf
•       - Petiole: Stalk that attaches blade to stem
•       - Axillary Bud: Originates from leaf axil

Plants that lose their leaves every year.

- Allows a plant to grow its entire life by retaining cells that have the ability to divide and produce more tissues

• - Meristematic tissue that is present in the root tip and shoot tip
• - Produces 3 types of primary meristem which develop into 3 types of specialized tissue
•        - Epidermal Tissue
•        - Ground Tissue
•        - Vascular Tissue

• - Forms the outer protective covering of a plant 
• - Modified in the roots, stems, and leaves

• - Forms the bulk of a plant and contains 3 types of specialized cells 
•        - Parenchyma: deeper within plant tissue
•        - Collenchyma: Under the cuticle
•        - Sclerenchyma: Lingin

Thickness of cell membrane.

• - Provides internal system of conduction
• - 2 types
•       - Xylem, Phloem

• - Vascular tissue that transports water and minerals from the roots to the leaves.
• - Complex Tissue
•        - 2 types of conducting cells
•             - Vessel elements: Shorter and wider with perforated plates in their end wall
•             - Tracheids: Long with tapered ends and are less efficient transporters, but allow water to move across end or side walls

• - Vascular tissue that transports sugars and other organic compounds throughout the plant.
• - Sieve-Tube members: 
•        - Arranged to form a continuous Sieve-Tube
•        - Contain cytoplasm, but no nuclei
•        - Have nucleated companion cell that keeps both cells alive  
•        - Connected by plasmodesmata  
• - Compound Tissue

Contains more than one type of cell

Stores the nutrient molecules that the embryo uses

• - One cotyledon
• - Endosperm is the food-storage tissue
• - Xylem and phloem in a ring
• - Vascular bundles are scattered
• - Leaf veins form parallel pattern
• - Flower parts in 3 and multiples of 3

• - Two or more cotyledons
• - Cotyledons supply nutrients to embryo and seedling
• - Phloem between arms of xylem
• - Vascular bundles in distinct ring
• - Leaf veins form a net pattern
• - Flower parts in 4 and 5 and their multiples

When water reaches the leaves and then ecaporates

• *Stoma are bordered by guard cells*
• - Influenced by environmental conditions
• - Open stomata: guard cells fill with water, gas exchange occurs
• - Closed stomata: guard cells are empty

• - Freshwater green algae 450 million years ago
• - Common Traits:
•       - Chlorophyll A and B
•       - Store excess carbs as starch
•       - Have cellulose in cell wall

• 1. Embryo Production
• 2. Vascular Tissue
• 3. Megaphylls
• 4. Seeds
• 5. Flowers

• - Two multicellular individuals (sporophyte and gametophyte) alternate, each producing the other
• - Plants differ as to which generation is dominant
•       - Dominant Generation: Most conspicuous and carries out most of the photosynthesis
•           - Nonvascular plants: Gametophyte 
•           - Vascular plants: Sporophyte 
•       - A shift to sporophyte dominance is an adaptation for life on land

• - 2n (Diploid)
• - Produces spores by meiosis

• - n (Haploid)
• - Produces gametes by mitosis
• - Sperm and egg fuse = diploid zygote

• - Gametophyte = Smaller
• - Sporophyte = Larger
• - Mosses and ferns: spores disperse gametophyte
• - Gymnosperms and angiosperms: seeds disperse sporophyte

• - Lack vascular tissue, true roots, stems, leaves
• - Dominant Generation = Gametophyte
• - Flagellated sperm swim to egg
• - 3 Divisions- Phylum: Bryophtye
•        - Horns, Liverworts (flat, lobed thallus OR leafy), Mosses

• - Live in a variety of enviornments
• - Most can reproduce asexually by fragmentation

• - Can live on bare rock, fences, cracks in sidewalks, stone walls
• - Help convert rocks to soil
• - Peat moss forms in bogs as it accumulates
•        - Used as fuel, holds water

• - Have vascular tissue
• - Have true roots, stems, and leaves
• - Dominant Generation: Sporophyte
• - Some do not produce seeds

• - Two groups: Lycophytes & ferns and their allies
• - Produce windblown spores
•       - Flagellated sperm released by antheridia
•           - Swim in a film of external water to archegonia

• - Phylum: Polypodiophyta
• - Largest group of plant other than flowering plants
• - Great diversity in form and habitat
• - Warm, moist, tropical regions

Dominant sporophyte produces windblown spores, when spore germinates the gametophyte (water dependent) develops.

• - aka Club Mosses
• - Among 1st land plants to have vascular tissue
• - Common in moist woodlands in temperate climates (ground pines)
• - Also in tropics and subtropics

• - Most plentiful in biosphere today
•       - Seeds contain sporophyte embryo and stored food which allows an embryo to survive long periods of dormacy
•        - Seeds germinate under favorable conditions
• - Heterosporous: two types of spores and produce male (produced by pollen grain) and female (develops in ovule) gametophytes
• -Gymnosperms and Angiosperms

• - "Gymno" = Greek for naked 
• - Most are cone-bearing 
•       - Ovules located on surface of cone scales
•           - Ovules not completely enclosed by diploid tissue
•           - Later become seeds
• - 4 groups: conifers, cycads, ginkgoes, gnetophytes

Deposition of pollen on a female gametophyte.

Path followed by sperm to reach ovule

• - Phylum: Pinophyta
• - Evergreens; best known gymnosperms
• - Oldest and largest trees on Earth
• - Adapted to cold, dry weather
• - Dominant sporophyte produces 2 kinds of cones:
•         - Pollen Cones (male) & seed cones (female)

• - Phylum: Ginkgophyta 
• - Maidenhair Tree = only surviving species
• - Females produce fleshy seeds that give off a foul odor
• - Resistant to pollination

• - Phylum: Magnoilophyta
• - Flowering plants
• - Very large and successful group 
•        - 240,000 known species
• - Live in all types of habitats 
• - Large size range (microscopic-100 meters)
• - Seeds develop from an ovule within an ovary, which becomes the fruit
•        - Covered seeds
• - Co-evolved with insects

Animal that carries pollen to another flower.

• - Tip of stalk that bears flower
•       - Also bears sepals, petals, stamens, and carpels

- Modified leaves that protect bud

- Modified leaves, may be colorful to attract pollinators

• - Male reproductive structure
•       - Anther: pollen production
•       - Filament: stalk

• - Female reproductive structures
•      - Stigma: pollen receptor
•      - Style: elevates stigma
•      - Ovary: ovule production and containment

• - Dependent on flower which produces both pollen and seeds 
• - Pollination can be wind or pollinator

- Final product of a flower, aids in the dispersal of seeds

Study of microbes.

• - aka Microorganisms
• - Bacteria, archea, protists, fungi, viruses, viriods, prions
• - Most require a microscope to be seen
• - Are everywhere 
• - Many cause human disease
• - Others provide important benefits

• - Late 1600s: 
•       - "Animalcules": microscopic life forms in water
•       - Spontaneous generation
• - Late 1800s: 
•       - Louis Pasteur
•            - Used microbes to discredit the theory of spontaneous generation in 1859
•            - Virus caused rabies

Single common ancestor (3.5-4 billion years ago).

• - Most common prokaryote on Earth
•       - 9,000 species identified, estimated to be 10s of millions unnamed species
• - Found everywhere
• - 3 shapes:
•       - Rod (bacilli), Spherical (cocci), Curved (spirillium)

• - Capsule (not present in all bacteria)
• - Cell Wall: helps determine different types of bacteria
• - Plasma Membrane 
• - Plasma
• - Single circular chromosome (DNA) located in nuceloid (RNA) region 
• - Plasmids: accessory rings of DNA that carry genes
• - Ribosomes
• - Storage granules

Based on size and structure

• - Used to classify bacteria based on differences in cell wall
• - Most widely used
• - Result (positive or negative) is used to select antibiotics
• - Gram Positive: Thick cell wall (thick layer of peptidoglycan)
• - Gram Negative: Thin or lacking cell wall (thin layer/lacking layer of peptidoglycan)

• - allows for survival in harsh conditions
• - Thick-walled, dehydrated structure

• - Asexual reproduction in bacteria
• - Replication & division = 2 new daughter cells
•       - Daughter cells are clones (exact copy)
• - Duration: 20 min - A day or more

Donor cell passes DNA to recipient cell via sex pillus.

Bacterium takes up DNA from environment released by dead bacteria.

Viruses carry bacterial DNA from cell to cell.

• - Require an outside source of organic compound
• - Aerobic: use oxygen
• - Anaerobic: use sulfate or nitrate

• - Reduce carbon dioxide to organic compound 
• - Uses electrons

• - Use solar energy to produce food
• - ex: Cynobacteria

• - Have chlorophyll and other pigments
• - 3.8 billion years ago
• - Most oxygen of Earths atmosphere

• - Bacterial disease
• - Many non-harmful strains live in our large intestines
• - E. Coli O157:H7 generates toxins that damage intestines lining

• - Cause more disease than any other bacteria 
• - Streptococcus pneumoniae: pneumonia, meningitis, middle ear infections
• -  Streptococcus mutans: contributes to dental caries
• - Streptococcus pyogens: causes the most diseases (ex: strep throat)

• - about 20% of people are carriers
• - Mostly skin infections

• - Staph strain resistant to methicillin
• - Can be deadly

• - A leading cause of death worldwide due to infectious disease
• - Very slow growing bacteria

• - Inhibit reproduction of bacteria by interfering with unique metabolic pathways
• - Work in 2 ways:
•       - inhibit protein synthesis
•       - inhibit cell wall biosynthesis

• - Acellular structures
• - Require a living cell to reproduce
• - Use host cells replication machinery

• - Simpler than viruses 
• - Proteins molecules that cause other proteins to become prions
• - Neurodegenerative diseases

• - Once in body, can reproduce and the person will have it in their body for the rest of their life
• - Even if asymptomatic, they are still infected

• - Smaller than bacteria
• - Shapes: helix, sphere, polyhedron, and more complex forms
• - 2 main components:
•       - Capsid (outer portion comprised of protein) 
•               - May be surrounding a lipid envelope
•               - May have spikes for attachment
•       - Nucleic Acid Core (RNA and DNA)
•                - Both may be single or double stranded

• - Infect almost every type of organism on Earth
• - Each virus is specific to a certain host