Lecture 16 Flashcards
what are the male and female parts on an angiosperm
males = anthers - they gather pollen
female = stigma - receives pollen
what does it mean to be sessile
plants: cant move around, can’t escape
autotropic
they make their own food through photosynthesis
- need water, light, CO2 and soil nutrients to grow
photosynthesis reaction
CO2 + H2O + energy –> Oz + glucose
cellular respiration = opposite and makes ATP energy
- plants must acquire more carbon through photosynthesis than they lose through respiration to grow
Net primary productivity (NPP)
it is the carbon gained from photosynthesis minus the carbon lost from cellular respiration = NPP
why are plants green
reflect green light
plants = CO2 from the stomata
plants also transpire - lose water thru the stomata
what is a tradeoff that plants off
Benefits: large leaf surface = good for photosyn, CO2 and more stomata (high SA/V)
Costs: large SA = bad for overheating, more water loss through transpiration via stomata
what are the different types of photosynthesis
different types of photosynthesis with different environments
C3, C4, CAM photosynthesis
C3: rubisco = enzyme that fixes carbon, but doesn’t work at high temperatures
C4: PEP enzyme carboxylase accepts CO2
CAM: plants that close stomata during the day and open at night to preserve water and let go of CO2 at night - desert plants
How do plants combat overheating
- growing in shady habitats
- evaporative cooling by opening stomata
explain evaporative cooling
needs lots of water which is not always available so they combat water loss by closing stomata - this = tradeoff bc it stops all gas exchange which stops all growing - desert plants
Palo Verde
a tree that has very small leaves = microphylly
- adapted to life in the desert
- green photosynthetic stems to counteract the small leaf SA
- when the winter, leaves drop and photosynthetic stems play
contrast the leaves in the rainforests vs deserts
rainforests = warm + wet, leaves are larger to = more SA
deserts = hot and dry, so leaves = tiny
Saguaro Cactus
- adapted to episodic rains (infrequent)
- CAM photosynthesis
- accordion pleated truck allows water expansion - to hold large amounts of water
how does cacti roots explain their place of living
wide but not deep
- the rain in deserts doesn’t penetrate very deep (gets dried up quickly)
how does tropical tree roots explain their habitat
wide but not deep
- for roots to gather the shallow layer of nutrient rich soil - needs to gather, phosphorus, nitrogen, etc
