bio exam 4

Identify traits of Archaeplastids

traits:

• autotrophic, from eukaryotic cell that engulfed bacterium, have chloroplasts

• protists

• land plants

Explain endosymbiosis and the origins of mitochondria and chloroplasts;

endosymbiosis: mutualistic, one organism inside another

mitochondria/chloroplast: eukaryote engulfs bacteria

Provide the general reactants and products of photosynthesis

CO2 + H2O creates sugar and O2

Explain why green algae are so ecologically important

• base of the food chain

• creates 50% of earth oxygen

• source of oil

• part of short carbon cycle

Describe three major cellular adaptations of plants (& the functions of each);

3 adaptations:

• chloroplast (photosynthesis)

• water vacuole (stores water for droughts)

• cell wall (rigidity)

List ways plants are vital for human society and ecosystems (relate to food webs, nutrient cycles, climate change);

• food

• oxygen

• nitrogen

• remove co2

• mental health

• prevents erosion

Explain why green & red algae are grouped with plants

red/green algae: 

• they were grouped bc they also perform photosynthesis

relate to evolutionary timeline and endosymbiosis

evolutionary timeline: 

• ~500mya algae moved onto land

endosymbiosis

• they all came from the eukaryotic cell that engulfed bacterium

Describe why algae are labelled as “red algae,” “green algae,” or “brown algae” (relate to chloroplasts)

algae labels are based on the wavelengths the chloroplasts reflect; they absorb all wavelengths except the color that they appear to be.

Explain why we get so many chemical products (e.g., medicine) from plants

we get lots of chemical products from plants bc they make them as defense against predation and pathogens

Recognize and reflect upon plant blindness despite the importance of plants

plant blindness bc of ppl ignoring or undervaluing plants or being scared of them bc of their lack of knowledge on them

Explain how the invention of the microscope impacted the study of biology

allowed us to observe microscopic structures (hyphae, stomata, xylem/phloem)

provide the approximate year when the microscope was invented

1650

List three groups of Excavata

• euglena

• trypanosomes

• giardia

List an important trait that distinguishes Excavata from other “protists”

the “excavated” feeding groove

Compare and contrast Archaeplastids to Euglena

• they have chloroplasts for photosynthesis 

• their chloroplasts are analogous through separate endosymbiotic events

Explain how humans interact with Trypanosomes and Giardia

trypanosomes:

• sleeping sickness

• chagas disease

• leishmaniasis

• all spread via bugs/flies

giardia

• parasite

Recognize groups (and examples) of the SAR clade

S

• brown algae

• diatoms

A

• dinoflagellates

• ciliates

• apicomplexans

R

• radiolarians

• foraminiferans

Explain the ecological importance of diatoms & brown algae

diatoms

• silica (shells)

brown algae

• Sargasso Sea

• dominant species

Explain the ecological/health importance of dinoflagellates & apicomplexans

dinoflagellates

• cause red tides

• makes toxins that build up in shellfish

apicomplexans

• malaria parasite

• toxoplasmosis parasite

  • alters rodent behavior

Identify the structure common among Radiolarians and Foraminiferans, and how the two major groups differ

they have outer skeletons, radiolarians are made out of silica and foraminiferans are made of calcium

explain why these groups are important in the study of evolution

their skeletons preserve very well in fossil records, so they show evolutionary patterns

processes plants undergo

photosynthesis

cellular respiration

endosymbiosis theory: I vs II

I: cell engulfs smth

II: cell engulfs cell that engulfed smth

what creates clades

endosymbiosis

what type of endosymbiosis created photosynthetic bacteria

primary endosymbiosis

plant cell functions

photosynthesis

lack of movement (vacuoles, chemicals, cell wall)

can control little or too much water

why can plant cells stand high humidity

they use cell wall other than not pop, while animal cells pop when theyre too turgid

what traits define mosses (bryophytes)?

• ancestral land plans

• from ~500mya

• first to move onto land

• no vascular system or roots (bc its short!)

• need water for reproduction

• long gametophyte stage

what traits define ferns (pterophytes)?

• from ~400mya

• vascular system

• has cuticle and stomata

• can grow tall for sunlight

• need water for reproduction

what traits define conifers (gymnosperms)?

from ~300mya (age of cycads)

DONT need water for reproduction

use pollen sperm

produce seeds (protected and has food supply)

short gametophyte stage in cones

sporophyte stage is large pine tree

what traits define angiosperms (flowering plants?)

from ~200mya

has vascular system, stomata, pollen, seeds

efficient pollination bc of coevolution with insects

seeds in fruits for dispersal

use double fertilization

what evolutionary shift allowed ferns to outcompete mosses

development of vascular system (xylem/phloem) allowed for tall growth, which allowed for more sunlight access

what evolutionary shift allowed conifers to live in dry environments

pollen (non-swimming sperm)

seeds (embryos with food supply)

what evolutionary shift made angiosperms successful

pollination and seed dispersal by animals

moss life cycle- dominant stage

gametophyte stage, where archegonia and antheridia are produced for fertilization of egg

fern life cycle- key structures?

sporophyte: fern

sori: holds spores in sporangia

has swimming sperm

conifer life cycle- key structures?

sporophyte: pine tree

male cones make pollen, female cones have eggs

gametophytes are microscopic inside the cones

which generation is haploid and which is diploid

gametophyte: haploid

sporophyte: diploid

gametophyte lengths related to evolution

moss: long gametophyte, short sporophyte

fern: short gametophyte, long sporophyte

seed plants: very short gametophyte, longest sporophyte

benefit of long sporophyte stage?

diploid, so a mutation in one copy can be backed in the other copy

xylem function

transports water from roots to leaves

stomata function

allows water vapor out via transpiration for gas exchange (CO2 in)

stomata, xylem, and phloem relation to photosynthesis

co2 enters via stomata, h2o enters via xylem, sugars are made and transported to growing areas by phloem, o2 exits via stomata

pollination definition

transfer of pollen (sperm) to stigma/female cone

seed dispersal definition

movement of seeds (embryos) away from parent plant

angiosperms pollination method

flowers attract pollinators, they get coated in pollen, spread pollen and the pollen sticks to the stigma of another flower

angiosperms seed dispersal method

animals eat fruit, seeds go thru digestive, they poop it out and it grows

why are seeds better than spores

sees have embryo, food, and a protective coat to survive harsh conditions

6 flower structures and function

petal: attract pollinators

anthers: produce pollen

stigma: catches pollen

style: tube pollen travels down

ovary: contains ovules, becomes fruit

ovule: becomes seed after fertilization

double fertilization

2 sperm from one pollen grain, one fertilizes egg and the other fertilizes endosperm for food

what is a vegetable

any edible part from roots, stems, or leaves

how is osmosis related to concentration gradients

osmosis moves water from high to low concentration, or going from low to high solute

it wants to go where solute is

how is osmosis related to water potential

water potential: tendency of water to enter a cell

water moves from high water potential to low water potential

how is osmosis related to turgor pressure

water enters a cell, causes high turgor pressure. this stops osmosis bc the pressure prevents more water from entering

how does water go into a root

enters via osmosis, root cells accumulate solutes, and this lowers water potential, which allows water to move in.

• root hairs increase surface area

• mycorrhizae increase absorption

casparian strip function

forces water and solutes to cross cell membrane before reaching xylem

keeps bad substances from going in

like a bouncer

three pathways water can take thru root, easiest to hardest

apoplast, moves outside cells

transmembrane, must cross many membranes

how does water move up thru xylem

cohesion: water sticking to other water

adhesion: water sticks to walls of narrow xylem thru capillary action

transpiration

evaporation of water thru stomata

over 90% water gained by roots is lost this way

how do stomata benefit the plant

allows co2 to enter and o2 to exit

how do stomata hurt the plant

causes water loss and wilting

requirements for stomata to open

guard cells must take in water when they take in K+

• light

• K+

• guard cells swelling

why do stomata close at night or in drought

night: no light, K+ leaves, water leaves, guard cells go limp, stomata close

drought: no water, guard cells dont fill

what increases and decreases transpiration rates

increase

• longer days

• high temps

• high wind

decrease

• high co2

• leaves falling

what is transported thru xylem vs phloem

xylem

• water and minerals

phloem

• sugar

sources and sinks for sugar

source

• leaves

sinks

• growing tissues

• roots

how does sugar move

leaves produce sugar, high concentration of solute attracts water into phloem, the pressure from this water pushes sugar to the sinks

relate cellular respiration to sugar movement

growing tissues do cellular respiration, and they use up sugar. this keeps sugar concentration low in these areas, which maintains the gradient

translocation

transport of sugar in phloem, due to high sugar at source and low concentration sink

how does plant transport relate to insect diversity

insects feed on phloem sap, and excrete honeydew

how does plant transport relate to fungi

mycorrhizae increase root surface area for water and mineral uptake

how does plant transport relate to fruit/vegetables

vegetables and fruits are used as storage sinks of sugar for future use

4 sensory abilities in plants

light, gravity, touch, chemicals

phototropism, heliotropism, photoperiodism

phototropism: growth towards light

heliotropism: plant follows sun 

photoperiodism: can detect day length and when to go dormant

gravitropism

roots grow down, stems grow up

thigmotropism

plant moves in response to touch

chemotropism

roots hunt for water/nutrients

how do carnivorous plants separate insects from raindrops

they count number or trigger hairs touched in a certain amt of time

4 plant defense behavior categories

physical (thorns bark)

chemical (toxins)

mimicry

cooperation/mutualism (helper animals)

allelopathy

plants release smth to kill other plants, reducing competition

mutualism: mycorrhizae and plants

mycorrhizae give plants minerals from rock, plants give mycorrhizae sugar (carbon)

mutualism: legumes and nit fix bacteria

legumes give nit fix bacteria sugars and molybdenum, nit fix bacteria give Nitrogen conversion

why do plants eat insects

for nitrogen to make proteins

what is soil made of

minerals, organic matter (humus), water, air

soil particle sizes and why it matters

sand (largest)

silt 

clay (smallest)

large size allows water to pass thru, but also cant hold nutrients

why is topsoil important

it holds the most organic matter and nutrients, and decomposers

why do praries have deeper topsoil

bc they have grasses w deep roots

how long does it take to make one inch of topsoil

1000 years

how fast are we losing topsoil

1 inch every 50ish years

topsoil erosion problems

• hard to grow crops

• ecosystem collapse

• more runoff, more eutrophication

topsoil loss prevention methods

cover crops, mulch

nine macronutrients

carbon, oxygen, hydrogen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur

COH

organic molecules, 97% of plant mass

nitrogen

amino acids, for proteins

phosphorus

ATP, DNA, cell membranes

potassium

stomata opening

calcium

cell wall and membrane strength

magnesium

chlorophyll

sulfur

amino acids