Exam 1 Flashcards
Prokaryotes
bacteria with no nucleus and no membrane-bound organelles
Eukaryotes
plants and animals with a nucleus and membrane-bound organelles
Organelles
like a cells organs, each have their own specific jobs
Cytoplasm
everything in the cell except the nucleus
Cytosol
watery matrix that organelles float in
Cell Membrane
-surrounds the cell and decides what comes in and out
-semi permeable: allows nutrients in and waste products out
-made of a phospholipid bilayer
-also called a plasma membrane
found in: plant cells, animal cells, and prokaryotic cells
Nucleus
-control center of the cell
-stores DNA (chromosomes)
-surrounded by the nuclear membrane
-also contains the nucleolus which make ribosomes
found in: plant and animal cells
Ribosome
-smallest organelle; not surrounded by a membrane
-makes protein according to DNA instructions
-two types: free ribosome-float free in cytosol and bound ribosome-attached to rough endoplasmic reticulum
found in: plant cells, animal cells, and prokaryotic cells
Rough Endoplasmic Reticulum
-transport system for materials in cell
-covered with ribosomes; site if protein synthesis
found in: plant and animal cells
Smooth Endoplasmic Reticulum
-transport system for materials in cell
-no ribosomes; it makes hormones and lipids
found in: plant and animal cells
Golgi Apparatus
-delivery system of the cell
-collects, modifies, and packages molecules in the cell
-distributes and transports molecules in vesicles
found in: plant and animal cells
Lysosome
-trash disposal of the cell
-contains digestive enzymes that break down waste
found in: plant and animal cells
Mitochondria
-the powerhouse of the cell
-only organelle that has its own DNA
-site of cellular respiration
-converts energy stored in food into energy the cell needs (ATP)
-sugar + oxygen –> carbon dioxide + water + ATP
found in: plant and animal cells
Chloroplast
-found only in plant cells and algae
-contains green pigment, chlorophyll
-changes sunlight (solar energy) into food like glucose (chemical energy)
Cell Wall
-found only in plant cells and some bacterial cells
-rigid, protective barrier (maintains cell shape)
-located outside of the cell membrane
-made of cellulose (complex fiber made of carbohydrates)
Vacuoles
-large central vacuoles usually in plant cells
-many smaller vacuoles in animal cells
-storage container for water, food, enzymes, waste, etc.
-supports cell shape in plant
found in: plant and animal cells
Which organelles are present in plant cells but NOT animal cells?
Chloroplasts and Cell Walls
Agronomic Crops
relatively low input, grown on large scale: wheat, soybeans, corn
Horticultural Crops
require more intense and constant care from planting to consumer delivery: fruit, nut, vegetable crops
Plants are
primary producers/autotrophs; they are the only organisms that can create their own energy from the sunlight
Photosynthesis
carbon dioxide + water (in soil) + sunlight –> oxygen + carbohydrate energy
What do plants need to survive?
-need to complete photosynthesis
-need proper nutrients (water, oxygen, sunlight, soil)
-need nutrients to form DNA, enzymes, act as chemical catalysts, etc.
How do plants reproduce?
Sexual Reproduction-pollen fertilizes an ova –> seeds
Asexual Reproduction-drop leaves, rhizomes & stolons (runners), bulbs
Propagation: reproduction facilitated by humans ex: cutting, grafting, etc.
What is respiration?
the process of converting sugars into energy
What are some of the ways that humans use plants?
food, fibers (clothing), shelter, medicine, fuel
What are the parts of a scientific experiment?
observation, research, hypothesis, experiment, conclusion, share results
What makes a scientific experiment “good”?
-if the experiment can be replicated with similar results (true replication or internal replications)
-prior research from adequate resources
-have to have a control group and experimental group
-tests lots of subjects for variability
Hunter Gatherer and Agrarian Societies
Hunter-gatherer and agrarian societies rely on hunting and plant cultivation to sustain life and wealth. They produce/gather all goods themselves.
Pros/Cons Hunter Gatherer
Pros: wide variety of food options
Cons: lacks stability
Pros/Cons Agrarian
Pros: boosts trade, self-reliant
Cons: specialization (leads to limited options within society)
Quantitative vs Qualitative
Quantitative: factual and less bias
Qualitative: can be bias and preferential
both based on observation
Limitations of Scientific Studies
1) difficult to assess rare effects
2) variability in subjects
3)conditions in lab are different than in “real life”
4)generally not long term
5)if long-term, based on self reported data
What are plant tissues?
*types of cells that are distributed throughout the plant, but perform similar functions no matter what organ they are located in
*this is different from plant organs (roots, stems, leaves, etc.) which are made of different tissue types combined to perform a specific function
What are the two types of Plant Tissue?
Meristematic and Permanent
Meristematic Tissue
young growth cells forming undifferentiated tissues; does not yet perform a specific function; active cell-division
Permanent Tissue
*already differentiated
*simple permanent–tissue contains one cell type
*complex permanent–tissue contains multiple cell types
Meristematic Tissue Examples
*shoot apical meristem
*root apical meristem
*subapical meristems
*intercalary meristem
*lateral meristems
*vascular cambium
*cork cambium
Shoot Apical Meristem and Subapical Meristem
located in the root tips of a plant and the tips of the new shoot and leaves
Root Apical Meristem
located at the tip of the root
Intercalary Meristems
active tissues that have been separated from the apical meristem by regions of more mature or developed tissues; ex: monocots like grasses (explains why grass leaf blades continue to grow after mowing even though the top has been cut off)
Lateral Meristems
*growth in width or girth
*Vascular Cambium: growth of new xylem and phloem
*Cork cambium: growth of new bark
Simple Permanent Tissue Examples
*parenchyma
*sclerenchyma
*collenchyma
*epidermis
*cork tissue
Complex Permanent Tissue Examples
Xylem and Phloem
Parenchyma Tissue
*made up of living thin-walled cells with large vacuoles and many flattened sides
*makes up the palisade mesophyll and spongy mesophyll layer of leaves–lots of chloroplasts!
*makes up the pith and cortex of stems and roots
*makes up the soft tissues of fruits
Collenchyma Tissue
*gives support to young stems, petioles, and the veins of leaves
*the walls and corners of the cells are thickened, primarily by cellulose, to provide reinforcement
Sclerenchyma Tissue
*composed of thick-walled cells found throughout the plant as sclereids (fibers)
*common in stems & bark, and are also found as stone cells in pear fruits and walnut shells
Epidermis
*a single exterior layer of cells that protects stems, leaves, flowers, and roots
*the outside surface of epidermal cells is usually covered with a waxy substance called cutin, which reduces water loss
*leaf epidermis of leaves is usually colorless except for the guard cells of the stomata, which contain chlorophyll, and are green
Epidermal Cell Modifications
*some leaf epidermal cells are elongated into hairs and are called trichomes
*the root epidermis lacks cutin–it develops root hairs, protuberances which actively absorb water from the soil
Cork Tissue
*occurs commonly in the bark of maturing stems, trunks of trees and potato skins
*cell walls are waterproofed with a waxy material called suberin
Xylem
*a structurally complex tissue that conducts water and dissolved minerals from the roots to all parts of the plant
*cells found in the xylem may be: tracheids, fibers, or parenchyma
Tracheids
*long, tapered, dead cells that conduct water through pits
*contribute significant strength and support to the stems of gymnosperms
Fibers and Parenchyma
*thick-walled sclerenchyma cells that provide support
*arranged in vertical files and act as food storage sites
Phloem
*conducts food and metabolites from the leaves to the stem, flowers, roots & storage organs
*phloem is comprised of: sieve tube members (angiosperms) or sieve cells (gymnosperms), companion cells, fibers and parenchyma
Sieve-tube members
long slender cells with porous ends called sieve plate and occur only in angiosperms
Sieve Cell
just like sieve-tube members but without a sieve plate and only occur in gymnosperms
Companion cells
aid in metabolite conduction and are closely associated with sieve-tube members
