Unit 3^Plant Physiology Flashcards
How is magnesium taken up by plants and what is it used for?
Magnesium is taken up by plants thru active transport
it is used to make CHLOROPHYLL 🍃
How are nitrates taken up by plants and what are they used for?
Nitrates are taken up by plants thru active transport
they’re used for making amino acids + growth
Where is adrenaline made in the body and what does it do?
Adrenaline is made in the adrenal glands [top of kidneys]
it triggers the ‘fight or flight’ which prepares body for action
It INCREASES HEART RATE (part of brain called medulla tells heart to beat faster)
What is meant by the term self-pollination
self-pollination=
Pollination which occurs in the same flower 🌷
What is meant by the term cross-pollination + what does this method rely on
Cross-pollination=
Pollination where pollen grains are transferred to a different flower 🌷 🌹
Relies on INSECTS 🦟 or WIND 💨to help them pollinate
Define the term ‘pollen grain’
A pollen grain is a structure in the plant that contains the male gamete
What is POLLINATION
Pollination is the transfer of pollen from anther to stigma
Suggest how the dry mass of 10kg of fresh potato tubers can be determined
- weigh them on a weighing scale
* then heat them until all the water has evaporated + the mass stays the same
Why can’t you test a fresh leaf for starch? 🍃
If you put iodine solution on a fresh leaf nothing will happen cos the WAXY surface of the leaf will not absorb the solution (hence no colour change)
Design an experiment to test leaves for starch
1) remove a fresh leaf that’s been in sunlight
2) boil leaf in water for 30 seconds to kill it (stop chemical reactions in the leaf) 💦
3) boil it in ETHANOL to remove colour + waxy cuticle 🥂
4) now wash in cold water to soften it
5) spread the leaf on a tile + put 10 drops of iodine solution on leaf
** any parts of leaf that contain starch will go blue black !!!!
What is meant by the term ‘variegated leaf’
Variegated leaves are leaves with parts naturally without chlorophyll
Describe the process of photosynthesis
Plants use light energy from the sun 🌞(absorbed by chloroplasts 🍃) to convert CO2 + H2O 💦 into chemical energy (glucose) + oxygen
There are more stomata on the lower epidermis of a leaf, why is this?
There are more stomata on the lower epidermis,
Cos less EVAPORATION takes place on the cooler+ shady underside of the leaf
Design an experiment to measure the rate of photosynthesis
1) use an aquatic plant like algae or ELODEA
2) place it in a test tube of water and then into a water bath with a thermometer 🌡 (to keep temperature of beaker constant)
3) use a lamp + alter the distance away from pondweed using ruler
4) count the bubbles formed per minute
5) the more bubble per minute the faster the rate of photosynthesis
Name the 3 factors that affect the rate of concentration and explain how they do so
LIMITING FACTORS!
☀️ LIGHT INTENSITY
• if light increased so will rate of PS, but to a certain point — beyond CO2 or temperature will be limiting factor
🗯 CO2 Level/ concentration
• if co2 increases so will rate of PS, but to a certain point — beyond temperature of light will be limiting factor
🌡 TEMPERATURE
• as temperature increases so will rate of PS, but to a certain point — if temp TOO HIGH enzymes will denature hence rate of PS decreases
(Usually the temp is the limiting factor cos it’s too low)
What does the xylem do (it’s part of the vascular bundle)
Xylem carries water + mineral salts from roots up shoot
What does the phloem do (it’s part of the vascular bundle)
Phloem carries sucrose + amino acids to all parts of plant (translocation)
What do plants need nitrates for?
Needed for cell growth (makes amino acids)
What is a sign that a plant is deficient of nitrates
Yellow leaves + stunted growth
🌕🌕🌕🌕
What do plants need phosphates for ?
To make DNA + cell membranes
What is a sign that a plant is deficient of phosphates ?
Poor root growth + PURPLE older leaves 🔮🔮🔮🔮🔮
What do plants need potassium for ?
To make enzymes
What do plants need magnesium for?
🌱 need magnesium for making CHLOROPHYLL
What is a sign that a plant is deficient of magnesium
Yellow leaves
🌕🌕🌕🌕
State 4 things plants use glucose for
- starch for storage
- to make proteins + DNA
- in cellulose for cell walls
- respiration (duh!)
What is diffusion
Diffusion is the net movement of particles from an area of high concentration to low
What 3 factors affect diffusion
1) TEMPERATURE
gives particles more kinetic energy making them move faster/ collide more/ more successful collisions = diffuse faster
2)CONCENTRATION GRADIENT
the bigger the difference in concentration gradient — the faster the rate of diffusion (when conc high outside the cell, substances diffuse into it where it’s lower)
3) SA: volume ratio
as ratio increases so does the rate of diffusion
Design a diffusion experiment in a NON LIVING system
1) cut agar jelly cubes of different SA:vol ration + put in dilute hydrochloric acid
2) time how long it takes for cubes to go colourless
3) the cube w the LARGEST SA:vol ration (smallest cube) will change colour fastest
4) Acid diffuses into the alkaline jelly cube + neutralises it
PINK💞 alkaline goes TRANSPARENT 🌫
What is OSMOSIS
Osmosis is the net movement of water molecules across a partially permeable membrane from an area of high water potential to lower water potential
What is meant by the term PLASMOLYSED CELL
PLASMOLYSED is when a plant cell loses water by osmosis, resulting in the cell membrane pulling away from the cell wall
What happens to a plant cell when it is put in sucrose solution
The plant cells vacuole will shrivel up + pull away from cell wall— the plant cell becomes flaccid cos the water has moved out by osmosis
What happens when an animal cell is placed in a pure water solution
It explodes as it has no cell wall to keep it
What happens when an animal cell is placed in a sucrose solution
The animal cell shrinks — becomes CRENATED
Why do plant cells need water
Because when a plant cell is well watered it becomes TURGID because of osmosis
These turgid cells make the contents of cell push up against the cell wall= TURGOR PRESSURE
What happens if you don’t water a plant
The plant will wilt + lose turgor pressure
Cell becomes flaccid cos of no water
Design an experiment to investigate the effects of osmosis in a living system
1) cut 3 potato tubers into identical cylinders
2) get beakers w 100cm^3 of pure water, v-concentrated sucrose solution and one with nothing (just potato)
3) leave cylinders in solution for 30 min
4) the ones in pure water = longer + fatter
The ones in sucrose solution = shorter + shrunk
Define the term active transport
The movement of particles against a concentration gradient from an area of low concentration to high using energy released by respiration
What makes the xylem vessels woody/strong
LIGNIN a woody material in the walls of the xylem vessels
Describe fertilisation in a plant
Once a pollen grain lands on the stigma of a flower (cos of wind or insects)
A pollen tube grows out of the pollen grain, down thru the style to the ovary into the ovule
Fertilisation is when the two nuclei fuse together to make a zygote. This divides by mitosis to form an embryo
Each fertilised female gamete forms a seed. The ovary develops into a fruit around the seed
Why do seeds need water
Water is needed to activate the enzymes that break down food reserves in the seed
Why do seeds need oxygen
For respiration which transfers energy from food for growth
Why do seeds need a suitable temperature for growth?
For enzymes inside seed to work
Where does a seed get its glucose for respiration when it starts to germinate
Seed gets glucose from its food store for respiration
What is germination
When seeds start to grow
When does the seed stop using its food store
When the plant has grown enough to produce green leaves which means it can get its food (glucose) from photosynthesis for respiration
