Biology 1002 Test 2

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Cell Wall of Prokaryotes

semi-rigid, premeable, made of peptidoglycan (carbohydrate w/ amino acid attached)
gives bacteria shape-- the design comes from the genome

bacilli- rod shaped
cocci & Spirilla- Spriral shaped

Cell Wall Shapes of Prokaryote

capsules of Prokaryotes

highly organized and firmaly attached to a cell wall-in prokaryote

slime wall of Prokaryotes

less organzed loosely attached to a cell wall-in prokaryote

Pili

Hair-like structures on surface of bacteria which is in attachment- in prokaryote

Endospore

protective "resting" structures
bacteria surrounded by durable cell wall
resistant to extreme conditions-in prokaryote

Asexual- thru Binary Fission
Sexual in the form of conjugations using plasmids

Reproduction of a Prokayote

autotrophs use photosynthesis or chemosynthesis
Heterotrophs including symbiotes

Energy Source Of a Prokaryote

Diseases caused by Bacteria

Gonorrhea, Syphilis, tuberculosis, Lyme Disease

Antibotic Resistance

Because of the widespread use (and misuse) of antibiotics some pathogenic bacteria have developed

Bioremediation

Making the environment better for living organisms

Deinococcus Radiodurans

•Survive 3000x more radiation than humans.
•Tolerate extreme dehydration, heat, and cold.
•Used to "chew up" toxic waste
•Exxon-Valdez oil spill
-"Super Bacterium"

Ergots

Fungal resting bodies
grow in rye and other grains

Ergotism

crawling sensation in the skin, tingling in the fingers, vertigo, ringing in the ears, headaches, hallucination, painful muscular contractions leading to convulsions, vomiting, and diarrhea. All of these symptoms are mentioned in the record of the Salem which trials.

Mycelium

the feeding network of a fungus (body)
- may be extremely large
-usually found underground or inside a decaying organism
-composed of wooden mesh of hyphae

Hyphae

the threadlike filaments of a fungus
-has a tubular cell wall that contains chitin
-surrounds the plasma membrane and cytoplasm

Chitin

o A Structural polysaccharide of modified sugars

o Makes up insect excoskeletons & fungus cell walls.

o Polymer with glucose subunits and Nitrogen containing functional groups.
o ONLY in Fungi.

Septa

o Structures which partially separate the cytoplasm inside the hyphae, found in many fungi.

Spores

o Haploid cell which can grow directly into a hypha.

o Can be produced sexually and asexually.

Saprobes

decomposers of dead material (most fungi).

Parasites

Fungi which grow on living organism

One benefits from the other, the other suffers or dies

EX: Dutch elm disease, Corn smut, Athletes foot, jock itch, yeast infection

Mutualists

Fungi that live interdependently with photosynthetic organisms.

 Symbiotic relationship, they both benefit.

Lichens

Symbiotic relationship b/twn a fungal species and either a cyanobacteria or unicellular photosynthetic eukaryote.
• If separated they die.

Mycorrhizae

symbiotic relationships b/twn fungi and the roots of a plant.

--Fungi help send the plant water, minerals and nutrients.

--Some of the sugars the plant produces are absorbed by the fungus.

Sac Fungi

Phylum Ascomycota


a. Named for the sac which contains several haploid spores.
b. Candida yeast: good yeast—bread and beer,
i. Bad yeast: thrush, vaginal infections.
c. Sexual reproduction via spores produced in asci (sac-like cases).
d. Asexual reproduction via naked spores (conidia).
i. Both produce haploid spores.

e. Sources of many interesting chemicals.
i. Penicillium—the source of penicillin.
ii. Fungi make antibiotics.
iii LSD

Club Fungi

Phylum Basidiomycota

a. Common mushroom, puffballs, stink horns, shelf fungi, plant-parasitic smuts & rusts.

b. * Usually reproduce sexually, septa present.
i. Honey mushroom- largest, oldest, heaviest living organism on plantet. Humongous fungus.
ii. A single clone of the honey mushroom Armillaria can cover more than 2,200 acres (1,600 football fields).

Basidia are generally found on the surface of gills

Imperfect Fungi

Phylum Deuteromycota

a. Named for the apparent complete lack of sexual reproduction in the life cycle.

b. Fungi whose sexual reproduction has not been observed.
i. Includes Athlete's foot fungus, Penicillium fungus, and Blue cheese fungus.

Meristem Cells

Undifferentiated embryonic cells (not specialized),
there are 2 types: apical and Lateral

Apical Meristem

Found at both ends of plants (roots and shoots).

Primary Growth", throughout life of plant, increases height

Lateral Meristem

 Ring-like structure in dicots and conifers.
 "Secondary growth", later in life, responsible for thickening of branches and trunks.

Primary Root

Fibrous root (monocots) or taproot (dicots) systems.
o Grow at apical meristems.

o Protected by root caps: a lubricating layer secreting a slippery slime layer and regularly slough off to make penetration easier.

Epidermis

-Thin, no waxy cuticle. Separates inside from outside.
-Root hairs increase surface area, H20 uptake.

Ground Tissue

Cortex and Endodermis

Cortex

Parenchyma cells for food storage.

Endodermis

Boundary b/twn vascular cylinder and cortex.

Vascular Tissue

Outer Edge of Vascular Cylinder

Branch Roots

formed off main taproots

carbon and oxygen

The rest come from soil

What two Nutrients come from the air?

Nitrogen and phosphorous

Plant growth is limited by the supply of what nutrients

a. The fungus converts insoluble soil nutrients into simpler water-soluble compounds that root hairs can absorb and transport. The fungus obtain sugars and amino acids from the plant.

How does the Symbiont Mycorrhizae (fungus) help get nutrients

Osmosis

diffusion of water along a concentration gradient of free water molecules.

Water moves from High to Low

Cohesion- of water molecules makes them stick together, resist being pulled apart which is Hydrogen bonds
Tension- water s being pulled up

How does water move up a plant against gravity?

Transpiration

1. Water evaporates out of leaf stomata.

2. Leaf is "dry" so pulls water out of Xylem.

3. Water leaving Xylem pulls up the water behind it.
a. Unidirectional, controlled by opening/closing of stomata.

b. The rate of transpiration is controlled by opening and closing the stomata.

Shoot

negative gravity tropisim
-forms specialized tissues

Moves from sources (things that make sugar like leaves) to sinks (things that use sugar like fruits)

Transport of Sugar

Pholem

contains a high sugar concentration bc of sucrose moving from a source to a sink

-is directed by sugar production and use

by fragmentation naturally (runners) or artificially (clippers)

Plant Asexual Reproduction

Combines genes from 2 different parents, offspring genetically different from their parents.

After fertilization the zygote develops into the seed (plant embryo) which will grow into a new sporophyte.

Plant Sexual Reproduction

Gymnosperm

Earliest seed plants

nonflowering seed plants such as conifer, gnetophyte, cycad, or gingko

Wind pollination used for fertilization

Advantage: do not need biological help
Disadvantage: inefficient process

*Angiosperms

Flowering plants developed ~130 million years ago
Flowers attract pollinators

1. Sepals: sometimes colored, Attractors.

2. Petals: Colored, patterned to attract., advertise the location of the flower

3. Stamens: Male Reproductive parts that are Composed of filament and anther.

4. Carpels: Female Reproductive parts that are Composed of Stigma, style, and ovary.

Flower Structure

Wind-Pollinated Flowers

Inconspicuous and unscented, produce LOTS of pollen (hit-or-miss strategy).

Animal-Pollinated Flowers

-Attract pollinators using colors and scents
-Stop unwanted visitors
-ensure pollination is the goal

Angiosperm Gametophyte Development

• Develop inside sporophyte flowers, very small and parasitic ( can't live on their own)

• Pollen Grains: the Male gametophyte.

-Pollen develops within the pollen sacs.

- Sperm cells

• Embryo Sac: Female gametophyte, produces egg cells. Sac development results in 7 cells.

-1 egg cell.

-1 Primary endosperm cell with 2 nuclei.

-5 Cells that degenerate.

1. Pollen lands on Carpel.

2. Tube grows from pollen down through carpel.

3. 2 Sperm go down tube to egg for double fertilization.
a. 1 Sperm fertilizes egg to from diploid zygote.

b. The other sperm fertilizes primary endosperm cell to form triploid tissue.

Pollination and Fertilization

aid in seed dispersal

The main function of the fruit is to

1. Hypocotyl - root

2. Epicotyl -shoot

3. Cotyledon -seed leaves (dicots have 2, monocots have 1).

3 parts of plant embryo:

1. Gravity
2. Light
3. Wind
4. Predators
5. Touch

What do plants respond to

Phototropism

The bending of plant towards light, 1st plant response studies (Darwin).

Cells elongate at different rates on opposite sides of plant, causing bending.

How does the plant bend?

Auxins
Gibberellins
Cytokinins
Ethylene
Abscisic Acid

5 Plant Hormones

1. cell membrane lipid structure
2. Cell Wall composition
3.rRNA subunit sequences

Difference in bacteria and Archaea

Protist

all eukaryotic
Mostly unicelluar
unclear differences between this and the rest of the Eukaryotes

Viroids

i. Even simpler and smaller than viruses
ii. Fragments of single-stranded RNA with NO protein coat
iii. Hijack cells; infects primarily plant cells including citrus trees, potatoes, avocados

Prions

i. Unusual infectious particles
ii. Protein particle with no genetic material (DNA or RNA)
iv. consist of a protein that is folded incorrectly and makes other proteins fold wrong
v. Origin? Developed as a by-product of living organisms

postive taxis- mover toard something
negative taxis- swims away from something
positive chemo taxis- swis toward a beneficial chemical
positive photo taxis- swims toward light
negative photo taxis swims away from light

taxis

heterokaryon

Unfused nuclei from different parents occupying the same unit of hypha
a. Written as n+n
b. This stage does not exist in animals

Asexual Reproduction Cycle of Fungi

1. Haploid (1n) spores are produced by mitosis
a. The spores are produced by the fungus taking haploid cells and using mitosis makes haploid spores
i. No variation produced through this process of asexual reproduction
b. spores are genetically identical to original mycelium
c. spores disperse and germinate to produce new mycelium
i. hopefully the spores move far away from "parent" fungus
ii. fungi have developed ways in which they try to spread out spores as far as possible from themselves so they don't compete

Sexual reproduction Cycle of Fungi

usually only under stressful conditions; spores are produced; many mating types are possible (essentially like having many different sexes or genders)

-the environment needs to change in someway
-plasogamy-the cells actually fuse together
-karyogamy-fusion of nuclei to produce zygote like structures
zygote like structures (2n)diploid
-meiosis - the zygote like structures then produce haploid spores through meisos
-then the spores are dispersed within the environment
**haploid spores may disperse long distances away from the fruiting body

Phylum: Chytrids

-Ancient group - diverged earliest from the other fungi
-Aquatic
-The only fungi with flagellated spores (zoospores)
-These spores can swim and require water for them to move around
iii.Sparobic
-Decompose dead material
-Majority of them are saprobic
iv.Parasitic
-Only some

Phylum: Zygote Fungi

i.Sexual reproduction via zygosporangia (resistant heterokaryons) that produce genetically variable spores
1.During sexual reproduction this fungus creates cells that are called zygosporangium, hence the name
ii.Asexual reproduction via sporangia that produce spores
iii.Mostly saprobic decayers of organic matter, e.g. soft fruit rot fungi and black break mold
iv.Some are parasitic, e.g. single-celled microsporidia

Phylum clomeromycetes = arbusular mycorrhizae

230 species now

Associated with about 90% of plant species

-To help conserve endangered plants and threatened environments
-To learn more about the natural world
-To better harness the abilities of plants to provide us with food, medicines, and energy
-Studying plants informs us about our world
-Viruses were purifed from pants

Why study Plants?

Mendels study of Peas

helped us understand human diseases such as sickle cell anemia and hemophilia, as well as countless other human diseases that have a genetic contribution

laid the foundation for the sciences of plant genetics and plant breeding

Phytophthora infestans

one serious disease that threathens the worlds food supply
cause of the potato late blight, has re-emerged as a threat

Puccinia graminis tritici

one serious disease that threatens the world's food supply

i. The wheat stem rust fungus
ii. A new, highly pathogenic strain emerged in Uganda in 1999-its called ug99
iii. This is a global problem that needs global attention, does not stop at its borders

Development of the seed and fruit

a. The first mitotic division of the zygote is asymmetric
b. This asymmetry provides the first environmental difference experienced by the differentiating cells and established the root-shoot axis
c. The sporophyte embryo develops from the zygote
d. The endosperm develops from the triploid endosperm nucleus
e. The ovule integuments become the seed coat
f. Tissues of the ovary (and sometimes the receptacle) become the fruit
i. Function of fruit is to aid in seed dispersal

Mechanical- Will actually shoot the seed out from the plant

Wind dispersal- white puffs

Water dispersal- Coconuts

Animal dispersal

Bird dispersal

Different ways of dispersing seeds

1. Water
2. Nutrients
3. Support the chute

Three main functions of a root

Can sense gravity, only on the tip of the root

How does a seed know how to grow roots downward

positive tropism

the change in the growth of the plant in response to environmental stimuli

negative tropism

- when the chute grows up/ against gravity

circadian rhythm

sleep cycle

Monocots

i. One cotyledon
ii. Veins usually parallel
iii. Vascular bundles usually complexly arranged
iv. Fibrous root system
v. Floral parts usually in multiple of three

Dicots

i. Two cotyledons
ii. Veins usually netlike
iii. Vascular bundles usually arranged in ring
iv. Taproot usually present
Has one main root with several branches breaking off from it
v. Floral parts usually in multiples of four or five

Shoot System

Terminal bud, node, internode, terminal bud of branch, vegetative branch, leaf (petiole and blade)stem,

Root System

taproots and lateral roots

1. Anchor the plant in the ground
2. Absorb water and minerals
3. Store surplus food, principally, carbohydrates, that were manufacures in the shoot during photosynthesis
4. Transport water, minerals, sugars and hormones to and from shoot
5. Produce some hormones
6. Interact with soil fungi and bacteria that help provide nutrients to the plant

Roots Functions

stem functions

1. support and seperate the leaves, lifting them into the sunlight and air
2. transport water and dissolved minerals from the roots up to the leaves
3. transport sugars

node

the petiole of a leaf is attached to the stem at a location called the

sporophytes

multicellular diploid form

the plants of gardens, orchards, forest and feilds that produce flowers

produces mother cells

pollen grain

male gametophyte enclosed within a protective, watertight jacket

consists only of 3-6 cells

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