Plant physiology Flashcards
what is a plant? (euk or prokaryote)
eukaryote
where is majority of DNA located in a eukaryote?
the nucleus
what does the nucleus allow for?
gene regulation
eukaryotes used to be divided into what two categories?
plants and animals
what are the three main features of a plant?
- obtains energy via photosynthesis
- multicellular
- reproduces through alternation of generations
organisms that photosynthesize are what?
autotrophs - “self feeder”
how do plants capture light energy?
using a complex pigment system that stores energy in organic molecules
what is a gametophyte?
a multicellular haploid with n chromosomes
what is a sporophyte?
a multicellular diploid with 2n chromosomes
how are plants classified?
based on features that have appeared over evolutionary history
who are the progenitors of the chloroplast?
cyanobacteria
where does photosynthesis occur?
in the chloroplast
what is chlorophyll?
a pigment that absorbs light energy in the blue and some red portions of the EM system
where is chlorophyll stored?
in the thylakoid membrane
what is an endosymbiont?
an organism that lives within another, dissimilar organism
how did the plant cell evolve to become what is known as a plant, today?
cyanobacterium entered a cell of an ancestral prokaryote, and evolved into a chloroplast through endosymbiosis. aerobic bacterium was also engulfed and became was is known today as the mitochondrion
define endosymbiont
the captured cell
what is the “Matryosha”effect?
secondary and tertiary endosymbiosis
define obligate endosymbiosis
host cell dependent on the organelle/endosymbiont
where did green algae likely appear from?
primary endosymbiosis
what do green algae specialize in?
utilizing the wavelength of light found in shallow water
define desiccation
to dry out thoroughly
define a stomata
a system of gas exchange that can open and close allowing oxygen to travel in as well as release carbon dioxide
what are zoospores?
sexual cells that are motile in water
how do aquatic plants float?
have floatation devices such as gas-filled stomata and intracellular spaces
what do plants need for growth?
minerals, contained in water
how are minerals obtained?
via the roots or even by air by some plants
what are the barriers to transition from aquatic to terrestrial life?
- dessication
- gas exchange
- reproduction
- buoyancy
- temperature fluctuations
- more light
- mineral nutrition
how did green algae transition from aquatic to terrestrial?
exposed to periods of drought, more complex forms of algae evolved such as liverworts and mosses
