Exam 1 Ch.1 Flashcards
plants, like animals are __________
Multicellular eukaryotes
Plants are _____
diverse
plants have evolved the ability to thrive in diverse land habitats
what are the types of plants
Land plants
Vascular plants
Seed plants
Flowering plants
plants make people
happy
plants produce considerable amounts of the _________ we breathe
oxygen
phytoplankton
produce the majority of earths oxygen (at least 50-80%)
plant produce most of the chemically stored energy we consume as _____ and _______
food and burn for fuel
plants produce an amazing assortment of useful _____
chemicals
Joseph Priestly
discovered oxygen in 1774
recognized animals breathing injured the air and passed out in sealed containers but recognized that plants restore the air when in the sealed container
we now know that plants produce oxygen as a __________ of photosynthesis
by-product
plants convert CO2 gas into sugars through the process of _______
photosyhtensis
plants can produce an amazing assortment of ______
chemicals
vitamin A, Vitamin C, vanillin, caffeine, morphine
why study plants?
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
informs us about the world
where were cells first observed
plants
_____ were first purified from plants
viruses
mendel’s studies of peas revealed the ___ __ _____ which helps understand human diseases such as sickle cell anemia and hemophilia as well as countless other human diseases that have a genetic contribution
laws of inheritance
mendels work laid the foundation for the sciences of ____ ____ and ____ ____
plant genetics and plant breeding
Norman Borlaug
distinguished plant breeder
the major objective of plant biology
to increase food production
we need to increase food production by
70%
how many people died from hunger in 2004
60 million people
how many people are hungry globally
1 billion people
how many people per year are chronically anemic due to iron deficiency
2 billion people
how do plant scientists contribute to alleviating hunger
By developing plants that:
are drought or stress-tolerant
require less fertilizer or water
are resistant to pathogens
are more nutritious
what is plant growth limited by
drought stress
drought increases with
increasing global temperature
how much do crop yields drop in warm regions
about 3-5% with every 1 degree celsius increase in temp
mild drought stress
reduces the rate of photosynthesis and growth, whereas extreme drought stress is lethal
the bad cycle
heat and drought reduce plant yields
more land must be cleared to grow more plants
removing tree to make more room for crops puts more co2 in the atmosphere
what can be altered to increase a plants drought tolerance
a single gene
what contributes to drought tolerance
a large root system
Fertilizer
energy-demanding limiting resource
whats in fertilizer
potassium, phosphate, nitrogen, and other nutrients
potassium and phosphate
are non-renewable, mined resources
synthesis of nitrogen fertilizers
requires huge amounts of energy
Agricultural fertilizer
a considerable source of environmental pollution
fertilizer run-off causes _____algal blooms that then decay, reducing oxygen levels in the water and making animal life impossible
dead zones
what can reduce the need for fertilizer
more efficient transport system in the roots
what plants is being used to cross crop plants to reduce crop plants dependency on fertilizers and water?
Perennial plants
- plants that uptake water and nutrients better than most crops
the two serious diseases that threaten the world?
Phytophthora infestans
Puccinia graminis tritici
Phytophthora infestans
cause of potato late blight, has re-emerged as a threat
Puccinia graminis tritici
the wheat stem rust fungus,
has developed into a highly
aggressive form
what destroys potato plants
light blight caused by Phytophthora infectants
genetics
identified the gene conferring resistance and are introducing it into edible varieties
identification of resistance genes
Ug99
wheat stem rust
highly pathogenic strain emerged in Uganda in 1999
most wheat has no resistance to this strain
global problem
carried by wind
what can improvement in nutrient content in plants help?
Alleviate malnutrition
Subsistence-level diets are usually nutrient-poor. Our bodies need vitamins and minerals as well as calories. Malnutrition is primarily a disease of poverty
fortifying foods
implementing vitamins(folate and vitamin A) and micronutrients(iron, zinc, and iodine) has dramatically reduced malnutrition in much of the world
Cassava
staple food crop in much of africa but low in nutrients
Scientists have recently identified a variant that produces much more vitamin A that the standard variety
what else do plants provide other than food
Plants:
* are sources of novel therapeutic drugs
* provide better fibers for paper or fabric
* are sources of biorenewable products
* provide renewable energy sources
compounds produced in plants that are used in medicines or drugs
*Willow (Salix) bark as a source of aspirin
(acetylsalicylic acid)
*Foxglove (Digitalis purpurea) as a source of
digitalis (treatment for cardiac problems)
*Pacific yew (Taxus brevifolia) as a source of taxol
(treatment for cancer)
*Coffee (Coffea arabica) and tea (Camellia sinensis)
as sources of caffeine (stimulant)
Malaria
The protozoan Plasmodium causes malaria
Plasmodium is transferred into humans by infected mosquitoes
Cinchona tree bark contains quinine, which kills Plasmodium but they are developing a resistance
Gin and Quinine
British soldiers in tropical regions were given quinine pills to prevent malaria. To disguise its bitter flavor, quinine was mixed with sweet,
carbonated water (“tonic”) and frequently also with gin – the origin of the “gin and tonic.”
Artemisia annua
a plant with novel antimalarial activities
Chinese herbalists have used Artemisia for
thousands of years. In 1972 the active ingredient, artemisinin, was purified
Plant scientists are developing higher-producing Artemisia
plants can make safe and inexpensive what?
edible vaccines and antibodies
plant cell walls
provide important durable material
composed mainly of carbohydrates and proteins
some contain rigid secondary walls that incorporate lignin, and insoluble cross-linking compound
plants also provide what
fibers for paper and fabric
petroleum
NOT a renewable source
plants can replace petroleum for many products and purposed
takes millions of years to convert dead organic matter into petroleum
biofuels
Plants can be a source of biofuels
Sugars, starches and cellulose can be fermented into ethanol
Biofuels produced from rapeseed, algae
and soybeans are replacing petroleum-
derived diesel
