Plant science midterm

  What are the 6 characteristics of living organisms?

• Have cell(s) and are organized

• Acquire energy and materials

• Grow and develop

• Reproduce

• Respond to stimuli

• Adapt to their environment

  What do the terms Community and Population mean?

Population- collection of the same species that interbreed

Community- collections of plants that live in the same area

What does the term Development mean?

• Development- growth and differentiation starting from a fertilized egg

     What are the 6 unique characteristics of plants?

• Must be multicellular eukaryotes

• Use of chloroplasts to carry out photosynthesis

• Store energy or food as starch

• Have cell walls made up of cellulose

• Have multicellular embryos that develop within female sex organs- flowers

• Have a life cycle alternating between haploid and diploid generations

• Nonvascular plants (bryophytes)

• Liverworts

• Hornworts

• Mosses

• No vascular tissues

• No true leaves, stems, or roots

• Rely on water for sexual reproduction

• Use spores for dispersal

Vascular seedless plants (club mosses, ferns)

• Lycophytes

• Have vascular tissue

• Have true stems and roots

• Rely on water for sexual reproduction

• Use spores for dispersal

Vascular seed plants

• Gymnosperms (cone bearing plants. Pine trees)

• Cycads

• Ginkgo

• Conifers

• Gnetophytes

• Have vascular tissues

• Have true leaves, stems, and roots

• Do not need water for sexual reproduction

• Use naked seeds for dispersal

• Do not have flowers

vascular seed plants- Angiosperms (flowering plants)

• Monocots

• Eudicots

• Have vascular tissues

• Have true leaves, stems, and roots

• Do not need water for sexual reproduction

• Use enclosed seed for dispersal

• Have flowers

length

• US metric- foot

• SI- meter

• 1 foot= .3048 m

mass

• US metric- pound

• SI- kg

• 1 pound= .454

temperature

• US metric- fahrenheit

• SI- Kelvin

• 1 fahrenheit= 256 kelvin

  What are the 4 major effects of plant domestication?

• More and larger fruits or grains

• Thicker stalks- more resistant to weather

• Seeds easily separate from chaff (protective covering)

• Nonshattering seeds- seeds stay on parent plant

Food plants: Legumes- Fabaceae family

• Food plants: Legumes- Fabaceae family

  •  Food, forage, cover, and oil crops

  • All produce “legumes”

  • Simple dry dehiscent fruits, typically pods with seeds

  •  Except peanuts

  • Simple dry indehiscent fruits

  •  Produce their own nitrogen through rhizobium bacteria in their roots

  • Beans, peas, lentils, and peanuts

  • An important source of protein

  •  Soybeans have most protein-40%, peanuts are the second- 25%

 Be able to describe which wheat variety is the most important type grown today? What is the second most important?

Most important- bread wheat

2nd most important- durum wheat

 Be able to recognize examples of each type of fruit found in the rose family (stone fruit = plums, peaches, etc.)

•  The rose family- rosaceae

• Stone fruits: plums, peaches, apricots, and cherries

• Pome fruits: apples and pears

• Aggregate fruits: strawberries, raspberries, and blackberries

For a product/crop to be recognized as a vegetable, it must have come from what part on the plant?

Food plants: vegetables

•  Plants that are entirely or in part edible for human consumption

• Have a savory flavor

• includes

• Leaves

• Leaf stem

• Roots

• Bulbs

• Fruits

• flowers

 Be able to describe and recognize the major characteristics of bamboo.

Commercial products: bamboo

•  Fastest growing plant on earth

• Flowering monocot- if you have a seed it grows one leaf (seldom)

• Reproduce both sexually and asexually

• Shallow but extensive root systems

• Vegetative propagation

• Culms (stems) are hollow

• Fast growth rate of bamboo make it an ideal plant for sustainable production of many materials

   Be able to recognize the differences between spices and herbs.

Commercial products: spices and herbs

•  spices

• Dried fruit, seed, root, or bark of plants

•  herbs

• Leafy part of a plant used fresh or dried

•  Generally used in dried form and very small

 What are the 3 components of the Cell Theory?

1. All living organisms are composed of one or more cells

2. Cells are the basic or smallest units of life

3. Cells come from pre-existing cell by cell division

What are the 4 common cell structures found in plant and animal cells?

•  Plasma membrane

• Selective barrier

•  cytoplasm

• Metabolic center and internal transport

•  Ribosomes- protein factories (copies Dna strand proteins or makes proteins)

•  DNA

• Blueprint of life

  Cytoplasm- Metabolic center and internal transport

 Cytosol- Metabolism: (types of reactions)

• Catabolic(breaking down complex molecules) vs. anabolic(creation of complex molecules) reactions

• Enzymes- speed up the process

 Cytoskeleton- Microtubules (thick protein fibers used for structural support) and actin filaments (thin protein fibers used for support)

• Cytoplasm streaming (transports materials back and forth)

   Endoplasmic reticulum- Biomolecule factories

• Rough

  • Protein synthesis

  • Has ribosomes attached to it

• Smooth

  • Lipid (fats) formation

   Vacuoles-  storage facilities

• Central vacuole

  • Up to 90% of plant cell volume

  • Turgor pressure- helps keep plants upright with water pressure

  • Stores:

    • Water

    • Salts

    • Water soluble pigments

    • waste

Chloroplast- Green plastids that make food

• Photosynthesis

• Carbohydrates and oxygen

• Have their own DNA and ribosomes

    Cell wall- Support and protect

• Made of Cellulose, held together by pectin, lignin

• Made up of two layers

• middle lamella- a pectin that acts as a glue to keep different plant cells together

• Plasmodesmata

• How plants are able to communicate and move things between each other

 What is the Theory of Endosymbiosis?

•  Origin of mitochondria and chloroplasts

• A eukaryotic cell engulfed a bacteria and incorporated it into its cell system

• Another eukaryote swallows another bacteria with a chloroplast and incorporated it into its system

• Own DNA

• Own ribosomes

• Semiautonomous

• Binary fission (prokaryotic cell division)

The ground tissue system- storage and support

• Parenchyma

• Thin primary wall

• Living w/ large vacuoles

• Can divide

• Can change

• Photosynthesis- can do photosynthesis

• Pretty much all chloroplasts are parenchyma cells

• Also close the wounds in plants

• collenchyma

• Thick primary cell walls- has lignin

  • Cellulose

• Living

• Support tissue

  • Leave veins

•  sclerenchyma

• Thick secondary cell wall

  • Lignin (fibers)- typically in woody plants

• Dead

• support/ protections

The vascular tissue system- transport

•  Two complex tissues

• Xylem

  • For transport of water

  • Tracheids

    • Found in patches

    • Lateral water movement

  • Vessel elements

    • For water movement upward

    • Stacked

    • Water pipes

• Phloem

  • Transports sugar wither from roots to leaves or leaves to roots by making a sugar syrup

  • Sieve tube cells

    • No nucleus, mitochondria, ribosomes

    • Are still living

• Ferns and gymnosperms only have tracheids

• Angiosperms have both tracheids and vessel elements

The dermal system- protection

• Two complex tissue

• Epidermis

  • Single exterior layer of cells

  • Herbaceous plants (non woody)

  • Upper epidermis forms the cuticle to prevent water loss and add protection

• Periderm

  • Multiple layers of cells

  • Woody plants

    • Uses lenticel for gas exchange on the woody exterior

    • Loose arrangement of dead cells that allows for the exchange

•  Stomata for gas exchange

• Uses osmosis

• On epidermis

       Be able to describe the difference between fibrous and taproot root systems.

• Taproot- thick primary root with tiny roots coming off of it

• Help plants dig into compacted dirt deeper to find deeper nutrients

• can defend better from animals and bugs

•  Fibrous roots- much finer that tap roots

• Typically grow more near the surface

• More root hairs= more surface area= more location for taking in nutrients

•  Some plants have tap roots and develop fibrous roots later on

    Be able to recognize and describe what happens in the 4 different root regions (root cap, cell division, cell elongation, and maturation)

•  Root regions

• Root cap- provides a pivotal roll in being a protective sort

  • Contain little pockets of hard beads that are always pointing down

  • Responsible for roots always finding their way down

  • For musagel (explode and release oily substance to lubricate roots to dig through hard soil)

• Cell division

  • Just to multiply cells

• Cell elongation

  • Cells become bigger and fill with water

• Maturation

  • Root hairs

  • Cells become specialized

   Be able to recognize examples of stolon and runner stems.

•  stolons (grass)

• Horizontal stem that roots at the node

•  Runner (strawberries)

• Horizontal stem rooting at terminal tip

sexual reproduction

• Requires two individuals

• Uses gametes

• Produces genetically different offspring: hybrid

• Produces genetic variation

asexual reproduction

•  Requires one individual

• Does not use gametes

• Produces genetically identical offspring: clone

• Does not produce genetic variation

  What does the term propagule mean?

-A plant portion that can develop into a new plant

    What are the advantages and disadvantages with asexual propagation?

• advantages:

• Reaches maturity quickly

• Allows propagation of difficult plants

• Produces uniform growth

• Maintains unique characteristics

•  Orchids are difficult to produce from seeds, so tissue culture is used to generate many clones

•  disadvantages:

• Plant propagules lose viability quickly

• No. of plant propagules from a stock plant is low

• Disease spread easily

• More expensive than seed propagation

  What is the most common type of asexual propagation?

Vegetative cutting

What do the terms scion, graft junction, and stock mean?

Stock- plant portion that has the roots and supports the scion

Scion- upper plant section that attaches to the stock

Graft junction- where the stock and scion meet

What 4 species of plants are the most commonly grafted?

• roses

• citrus

• apples

• grapes

   What are the 7 objectives for pruning?

• Health and safety

• Maintain desired form

• Dwarfing

• Invigoration

• Increase productivity

• Equalize root/shoot ratio

• Develop strong branch framework

 What do the terms anabolic, catabolic, endergonic, and exergonic mean?

•  Anabolic processes

• Build complex molecules

• Photosynthesis falls into this category

•  Endergonic processes

• Require energy input

• Photosynthesis falls into this category

•  Catabolic processes

• Cellular respiration

• Break down complex molecules

•  Exergonic processes

• Release energy

• Cellular respiration

Be able to recognize the differences between photosynthesis and cellular respiration (where each occur, anabolic vs catabolic, what the process does)

•  photosynthesis

• Take places in chloroplasts

• Anabolic and endergonic process

• Building more complex molecules from smaller molecules in several steps that use energy

•  Cellular respiration

• Takes place in mitochondria

• Catabolic and exergonic

• Breaking down of molecules and releasing energy

    Which wavelengths of light does Chlorophyll a absorb?

• Chlorophyll a- blue and red

  What are the 3 essential components of photosynthesis? What are the two stages of photosynthesis?

• Essential components of photosynthesis

• Light

• Pigments- take in wavelengths of light

• photosystems-

•  The two stages of photosynthesis:

• Light reactions- first part of photosynthesis

  • Takes place in thylakoid

  • Energy-transduction reaction

  • Light hits chloroplast and is absorbed in photosystem II

• The calvin cycle

  • Takes place in the stroma

  • Light energy used to synthesize simple sugars

  • Series of redox reactions reduce CO2 to glucose

• The light dependent reaction:

• Captures light energy from the sun

• Converts light energy to chemical energy

• Occurs in the thylakoids/grana of the chloroplast

• Photosystems II and I work together to produce ATP and NADPH, and chemical energy

• Water is a source of electrons

• Oxygen released

• The calvin cycle

• Consists of three phases

• CO2 diffuses entering through stomata

• CO combines with rubisco

• CO2 molecules are linked, adding one molecule with each phase until G3p (glyceraldehyde 3-phosphate) are produced

• Phase 1- carbon fixation with Rubisco into PGA

• Phase 2- reduction (gain electrons, oxidizing is losing electrons) 6 phosphate from ATP combines with the 6 electrons from NADPH combine with PGA to make 6 glucose/G3P

• Phase 3- Glucose/G3p combines with phosphate from ATP to regenerate Rubisco

• End- 1 G3P is left

• Depends on ATP and NADPH produced in light reactions

• Takes 3 cycles to produce 1 G3P (synthesizes into glucose)

• Plants that use the calvin cycle are known as C₃ plants

What are the two primary energy carrying molecules for cell processes that require energy?

Major energy carriers

•  Atp- adenosine triphosphate- major provider of energy for processes in plants

• NADH- nicotinamide adenine dinucleotide- role in generating energy as electron carrier

  What does the term photorespiration mean? What happens during this process and why does it happen?

photorespiration

•  Hot and dry conditions (water-stressed plants)

• Closure of stomata to conserve water however when they close for a long period of time they can not exchange oxygen

• Changes in the CO₂ and O₂ ratio

• Rubisco fixes O2 instead of CO2

• Wasteful and unproductive process

• Does not produce G3P

• Releases CO2 and uses ATP