Unit 1 Flashcards
How long have land plants been on earth?
400 million years (estimated)
Where and when were plants first domesticated
Mesopotamia, 10,000 years ago (modern day Iran, Iraq, turkey, and Syria)
What were the first domesticated plants?
Wheat, Barley, Lentils, and peas
Other early civilization plats that were domesticated were?
Rice (Asia) and potatoes (South America)
What are 3 common traits selected during crop domestication?
Larger in size, reduced shattering, and eliminating crop dormancy.
What were the benefits of plant domestication?
- Allowed fewer people to provide more food
- Stability (predictable food production)
- Created time for people (did not have to hunt all day)
- Resources for trading
- Advancements in tool production
- Formation of cities – the first villages and cities were built near fields of domesticated plants
What are three recently domesticated wild species?
Sugar beet, Sunflower, Wild rice
Where would you find a plants species greatest biodiversity?
Its center of origin
Center of Origin of Crop Plants
Origin of crop plants is now basic to plant breeding in order to locate wild relatives, related species and new genes (example disease resistance)
Where are global plant genes stored?
In a germplasm (dooms day vault)
Global issues
- Increased human population
- Energy use (50% increase in global energy use expected in the last fifty years)
- Drought
Plant Scientist are working to help global problems
by?
- More drought tolerant crops
- Require less fertilizer or water
- Crops more resistant to pathogens
- Crops more nutritious
How many households are food insecure in the United States?
Estimated 10.5 percent of U.S. households were food
insecure in 2020, meaning that they had difficulty at
some time during the year providing enough food for all
their members.
What is VAD
Vitamin A Deficiency
Has killed millions of children in less-developed countries (over 2 million in the early 1990s alone)
What else can we use plants for?
Plants produce hundreds of compounds we use as medicines or drugs
Plants can be a source of biofuels
Plants produce an amazing assortment of chemicals
Many discoveries were first described in plants
Number of plants in the world?
How many do we grow for food?
- There are 450 families of flowering plants and well over 350,000 different species.
- It is estimated that 3000 have been used by humans for food.
- Fewer than 300 have been domesticated.
- Only 20 plants that stand between humans and large-scale global starvation.
Definition of plants
- Plants are living organisms that contain chlorophyll and use it to manufacture their own food
- 335,000 species of plants
- Cell walls
- 500,000+ different kinds of plants and plantlike organisms
Plants have the ability to change over time (to evolve)
Population vs Evolution
Population – interbreeding group of organisms that share a gene pool
Evolution – accumulated changes in the gene pool
A. Natural selection
B. Artificial selection
Natural Selection
Natural selection due to pollinator preference lead to different species of monkeyflowers
Artificial Selection
Selection imposed by humans on population
Brassica oleracea lead to kale, brussels sprouts, broccoli, Cabbage, cauliflower.
How do we classify plants?
- Plant taxonomy based on system by physician and botanist Carl Linnaeus (1707-1778)
- Classification based on flower and reproductive parts of a plant
What is Morphology
What is the order of plant Taxonomic hierarchy
Kingdom
Phylum (division)
Class
Order
Family
Genus
Species
Classification – Scientific Name
- They are organized and evaluated
according to a definite system of laws and
rules - Plant distributed throughout the world
have the same valid scientific name - A plant can have only one valid name
- Only one plant may have this valid name
- A scientific name is very often descriptive
of the plant
Classification – Common Names
- They are the only names known
and familiar to most people - They are usually simple and
relatively easy to remember (ex.
windflower, mayflower, etc) - Descriptive of the plant (ex.
Bleeding heart)
Fabaceae Family
Legume
Variety
- Subspecies, denotes a fairly
consistent, natural occurring
variation - This second specific name is
preceded by the abbreviation - Ex Gleditsia triacanthos var.
inermis
Annual life cycle
An annual plants entire life cycle from seed germination to seed production occurs in one growing season, and then the plant dies
Biennial
A biennial plant starts from seed and produces vegetative structures and food storage organs in its first full season. A rosette of basal leaves persists through winter. During the second season, the plant’s life cycle is completed with flowers, fruit and seed.
Perennial
Is a plant that lives for more than two years. Typically, perennials die back in the fall and
return in the spring because of some sort of
overwintering structure, such as a rhizome or crown.
Woody plants
Woody plants - have stems that live for several years, adding new growth (height and width) each year. Woody plants may be classified as trees, shrubs or vines.
Herbaceous plants
Herbaceous plants – plants that have stems that die back to the ground each year. Herbaceous plants may be annual, perennial or biennial
Monocots
Dicots
Genotype vs Phenotype
- Genotype – The genetic make-up of an organism (collection of genes)
- Phenotype – The external
visible appearance of an
organism
What are the key points of seed maturity
- Most seeds can germinate before physiological
maturity - Some seeds only reach maximum germination after
slow drying - Few species can germinate at low oxygen tension
Germination temperature
- Minimum – rate of germination is
greatly reduced (may favor disease
development) - Optimum – Maximizes the rate and
total germination of a species. Best
temperature for successful
germination and growth - Maximum – Highest temperature for
seed germination (usually between 30
-40 C)
What is Dormancy
State of suspended growth to survive adverse conditions and aid in dispersion
What is Seed coat dormancy
When the seed coat is
impermeable to water (weathering, microorganisms,
passage through an animal’s digestive tract, fire, etc.)
What is Stratification
Cold and moist conditions used to overcome
dormancy
What is scarification
n some plant species (especially some trees) require scarification metal file or coarse sandpaper
What is the seed coat (monocot)
Forms the wall of the embryo
Endosperm (monocot)
Food supply
containing 3 sets of
chromosomes (2 from
mother and 1 from father)
Embryo (monocot)
Immature plant
Cotyledon (monocot)
Seed Leaf
Plumule (monocot)
Shoot
Seed Coat (Dicots)
The protective outer covering
of a seed.
Embryo
Immature plant
Cotyledon
Food storing seed leaf
Hypocotyl
Stem
Radicle
Root
Where is the energy stored in a dry bean seed as compared to corn seed?
Non-endospermic vs Endospermic
Endosperm - * The endosperm is referred to as
the food portion of the seed.
* Starch and proteins in this area of
seed are turned into sugars and
amino acids to supply energy to
the growing embryo
* Caryopsis (kernel) – special fruit
and seed formed by grasses
What is a whole grain
- Contains three parts of a kernel (bran, endosperm, and germ)
- Bran – outside coat and contains B vitamins and fiber
- Germ – the embryo B vitamins, protein and healthful fats
- Endosperm – mainly starch (carbohydrates, some protein)
Examples of whole grain
Wheat, brown rice, wild
rice, oats, barley, quinoa,
rye, popcorn, etc.
Why do we eat whole grains?
B vitamins, protein, fiber, magnesium, iron, phosphorus, and vitamin E.
What is Epigeal
cotyledon is raised out of the soil by extension of hypocotyl
What is Hypogeal
Hypocotyl remains short and compact and cotyledons remain beneath the soil
Dicots vs
monocots
- Many (not all) – dicots have epigeal emergence
- Many (not all) – monocots show hypogeal emergence
What does viable mean
Refers to a seed that is alive
What does dormant mean
A seed that is not actively growing
What is germination
A sprout from a seed (usually underground)
What is Emergence
A seedling breaking though top layer f dirt
What is a Meristem
a region of cells capable of division and growth in plants.
* Meristematic tissues (know apical and axillary)
* Apical meristems
* Shoot
* Root
* Subapical meristems
* Intercalary meristems
* Lateral meristems
* Vascular cambium
* Cork cambium
- How can we use plants to reduce environmental impacts?
The legume family – fertilizers – oxygen and carbon dioxide
- What is vascular tissue?
- How does soil influence plant growth?
Depending on how airated and nutrition the soil is
How can we use plants to address global issues (provide three examples)?
- More drought tolerant crops
- Require less fertilizer or water
- Crops more resistant to pathogens
- Crops more nutritious (VAD)
Why is the legume family one of the most important plant families?
Symbiotic relationship, putting carbon dioxide in the soil
Compare and contrast monocots and dicots (include all plant structures).
- Where are nutrients stored in a corn caryopsis as compared to dry bean seed?
Corn - Endosperm
Bean - Cotyledons
What is an example of a plant that can germinate at low oxygen tension?
Cattails – wild rice
How does temperature influence seed germination and growth?
how many plants are in between global starvation
20 plants in between global starvation
What is a fruit called in grass
Caryopsis
What is a stem called in a grassy plant
Culm
What are roots functions
- To absorb nutrients and moisture, anchor the
plant in the soil, support the stem and store food - Roots have a profound effect on plants size and vigor
What are the two types of root
- Primary root originates at the lower end of a seedling’s
embryo (also called taproot). - Secondary roots (lateral) –branched roots that arises
from another root.
what is a root Epidermis
the outermost layer of cells (absorb water and minerals dissolved in water)
What is a root Cortex
cells involved in moving water from epidermis to vascular tissue
(xylem and phloem)
How many inches underground does the majority of nurturance get absorbed by roots?
12 inches
What is a stem Shoot
A young stem (one year old or less) with leaves.
What is a stem Twig
A young stem (one year old or
less) that is in the dormant winter
stage (has no leaves).
What is a stem Branch
A stem that is more than one
year old, typically with lateral stems
radiating from it.
What is a stem trunk
A woody plant’s main stem.
VS - Xylem
tubes conduct water and dissolved minerals
Vs - Phloem
tubes carry food such as sugars
Stomas?
Openings in a plants leaves/cells to let in CO2
Regulation of
moisture, gas exchange,
and temperature through
small openings on the leaf
What is a Perfect Flower
one in which both male and female reproductive structures are present
What is a Imperfect Flower
does not have both male and female structures
