Plants Lesson 1 Flashcards
Who is Fungi more related to?
Humans over plants
Agriculture
The domination of plants and animals.
When was agriculture invented?
10,000 years ago, in multiple locations. However, Iraq had the first big event and it started with wheat and other grasses.
Wheat
The majority of the calorie intake.
Pasture
Raising animals (big part of the earth’s surface)
Cropland
Raising plants
Impacts of Agriculture?
Permanent villages, towns & cities. Larger family so
larger population. Diverse economy. Less cooperation (because different individuals could have different roles and they wouldn’t directly interact with one another in these roles), Socioeconomic classes, Separation of humans from rest of nature, Large-scale war
Chocolate
A plant made from the seed of the chocolate tree called theobroma cacao.
Where do fruits come from?
Flowers, and seeds are in fruits. The seeds are made to reproduced and each seed becomes a new tree.
Rubber
The word comes from how we can rub out pencil marks. It comes from the rubber tree (Hevea brasiliensis) from Brazil and is now grown in other pieces because of parasites in Brazil that aren’t in other places. If you score the bark and put a bucket there, then a rubbery material will run out of it. Then heat it up and it will turn into rubber.
Cotton
Clothes are made from it. It’s made of the cell walls of plants (Gossypium spp.) Lots in the US. Specifically made from cellulose, a polymer.
Polymer
Many molecules put together in a chain.
Drugs
Plant’s secondary compounds because it’s not nesscary fro metabolism, growth or development. Plants are the original source of most drugs. These drugs are used by the plant as defence to fight off things that might eat them. 200,000 compounds estimated.
Quinine
Plant: bark of cinchona tree (Cinchona pubescens & other spp.). Natural range: South America, now
widely introduced worldwide. Treat malaria from 1650’s in Europe. Also: anemia, muscle spasms,
cancer, tonic water (makes it bitter).
Caffeine
From the coffee tree (coffee arabica) from Ethiopia. Flower to fruit to seed (coffee bean).
Aspirin
Acetylsalicylic acid (found in willow trees and bark). Treats pain, fever, inflammation. Willow species: genus Salix.
Tetrahydrocannabinol (THC)
Found in Hashish and Marijuana (Cannabis sativa).
Nicotine
It’s an alkaloid. Found in tobacco (Nicotiana tabacum).
What four drugs come from Opium poppy (papaver)?
Opium, Heroin, Morphine, Codeine.
Taxol
From yew (evergreen): Taxus. Cancer treatment:
chemotherapy for ovarian, breast, lung.
How is the oxygen in the air created?
50% is made by land plants, other 50% by marine photosynthesis organisms.
Important of Plants?
Energy: food (agriculture). Energy: fossil fuels. Clothing. Drugs, medicines. Ecosystem functioning
Biodiversity.
What’s Botany?
The study of plants
Different types of botany?
Evolution (adaptions of plants)
Ecology (Community & Population) (interaction of plants and environments)
Molecular genetics (how genes get plants to do things)
Mathematical modelling (ie. best leaf shape in rainforest)
Morphology (external)
Anatomy (internal)
Physiology
Cell biology
Systematics (how organisms are related)
Development
Pollination of Cardinal flower (Lobelia cardinalis)?
It’s the only member that has red flowers and is only pollinated by the Ruby-Throated Hummingbird. It makes nectar and the hummingbird takes it and gets pollen on its head and carries it to other places. Each flower is first a male then becomes a female. Younger plants at top and older at the bottom. If it then visits a female and puts pollen on it, then it’s self-fertilization.
What’s a plant?
It’s defined in many ways.
The cladogram of plants?
Ancestral alga, then red-green split (1500 mya), then the chlorophyte-streptophytes split (1000 mya).
Plastids
In 1558 mya. Organelle in plant cells that once acted as free living bacteria like chloroplasts. There was an agreement between chloroplasts and plants cell. If it keeps it safe and it does photosynthesis for it.
Viridiplantae
Chlorophytes (originally marine) and Streptophytes. Plants are all organisms in this class.
Streptophytes
Mostly fresh water and includes the land plants. Charophytes and Embryophytes.
Land plants
Embryophytes
Primary Endosymbiosis
prokaryote + eukaryote = eukaryote. Nonphotosynthetic eukaryote engulfed a
photosynthetic cyanobacterium (now a plastid).
Secondary Endosymbiosis
eukaryote + eukaryote = eukaryote. Nonphotosynthetic eukaryote engulfed a
photosynthetic eukaryote (green or red alga).
Plants split from red algae ~1500 mya?
both single-cell and multicellular forms, mostly marine, moist environments near ocean shores
500 mya: colonization of drier environments?
Adaptations to live on land: Cuticle, Vascular tissue: roots & shoots, Relationship with fungi, Seeds and pollen
How many species since the colonizing of land (the organisms invaded the land)?
290,000 species
What did atmospheric oxygen do?
Created new ocean chemistry and new atmosphere where O2 is more available, allowing animals to evolve.
Oxygen Revolution
The oxygen increase was because organisms were photosynthesizing and growing in numbers and diversity. This brought about the land animals.
The major events in history of plant life?
Earth forms (4550 mya), Photosynthesis appears like cyanobacteria (3550 mya), 1st Plastid and plants & red algae diverge (1500 mya), Colonization of land by plants and fungi and then animals (500 mya).
Features of all plants?
Strach, chlorophyll b, cellulose, Thylakoids in stacks
Strach
The main energy-stirage molecule. Polysaccharide (carbs) of glucose residues. Easily broken down into sugar because it’s made up of sugar.
The two types of starch?
Amylose (20%): a straight line of glucose
Amylopectin (80%): Branched glucose, with an extra chemical bond.
Impact of sugar as an energy storage?
Not very reactive (good), easily metabolized (good), absorbs and holds water (meaning increase and decrease of size) so starch is the solution.
Chlorophyll b
Chl a: all photosynthetic eukaryotes have it.
Chl b: accessary pigment; passes energy to Chl a.
Chl b absorbs slightly different wavelengths from Chl a.
Cellulose
It’s major component of cell wall. Most common organic polymer on earth. Cotton is 90% cellulose. Used to make: Paper, rayon, cellophane
Polysaccharide
Unbranched glucose residues (different bonds from starch)
Thylakoids in stacks (“grana”)?
Rather than as simple bands. Thylakoids are membranes inside chloroplast—contain chlorophyll.
Granum
A stack of thylakoids
The ancestors of land plants?
Charophytes are the closest relatives of land plants
Evidence: both nuclear and chloroplast DNA and anatomical structure. It’s a type of “green alga.”
Land plants are not descended from modern
charophytes, but share a common ancestor with
modern charophytes.
Features of charophytes and land plants?
Cell plate & phragmoplast
Plasmodesmata
Sperm structure
Peroxisome enzymes
Rose-shaped cellulose-synthesizing complexes
Sporopollenin: durable polymer
Charophytes and land plants way of divided?
By starting in the middle and separate outward. Cell plate arms then mircotubles on either side of the plate pull the centre of the cell away from one another.
Phragmoplast
Short microtubules
Plasmodesmata
Extensions of cell membrane through pores in cell wall
Sporopollenin
Durable polymer. Found in walls of: Plant spores and Pollen. Chemically inert: Stable and Persists in
environment. Protects from desiccation, decay, etc. Impermeable to bacteria and viruses, so the cell it houses is protected from the world.
Potential Advantages of the move to land?
Air filters less sunlight than water. There’s more light for photosynthesis. Air has more CO 2 than water. There’s more fuel for photosynthesis. Early terrestrial habitats lacked pathogens or predators/herbivores.
Terrestrial soil is richer in nutrients than aquatic soil. Land plants grown in height and diversity.
Land plant Adaptations to be supported (normally not supported)?
Turgor (positive pressure); Cell walls with lignin; Xylem; Stems
Land plant Adaptations to retain water (normally loses water)?
Cuticle; Vascular tissue; Roots; Stomates
Land plant Adaptations to make reproduction easier (normally harder)?
Egg & embryo retained on parent; Sporopollenin; Protected embryo; Seed coat; Pollen; Flower; Fruit
How is reproduction easier on water plants?
Sperm swim in water. Dispersal easy (float). Eggs not dry out.
How is reproduction harder on land plants?
Sperm cannot fly. Young not dispersed. Eggs & embryos need protection from drying out, predators,
…
Features of land plants?
Cuticle. Multicellular, jacketed sex organs. Embryophyte condition. Alternation of generations
Jacketed Sex organs
Protects the sex organs
Gametangia
Makes sperm or egg
Antheridium
Male sex organs. Haploid. Produces sperm.
Archegonium
Female sex organ. Haploid. Produces egg.
Embryophyte condition
Plants that have embryo kept on them. Fertilized egg stays on the structure that made the egg.
Are embryo and material tissues haploid or diploid?
Embryo is diploid (2n)
Maternal tissue is haploid (1n)
Alternation of Generations
Means both haploid and diploid stages have multicellular components.
Multicellular haploid does what?
Makes the sperm and egg.
