Exam 1 Flashcards
Define ecology in the context of plant studies.
Study of organism interactions
Ecology examines interactions between physical, chemical, and biotic environments.
What is plant ecophysiology?
Biological discipline studying organism’s physiology response to environmental conditions
What are embryophytes?
Land plants
What distinguishes spermatophytes?
Seed plants
What are gymnosperms?
Naked seed plants; seeds developed in cones
What are angiosperms?
Vessel seed plants; seeds developed in ovary
What is the function of the plasma membrane in plant cells?
Transfer substances in and out of the cell
What is the cytoplasm commonly referred to as?
Cellular soup
What is the role of the nucleus in a plant cell?
Stores genetic material and controls protein synthesis
What is the function of ribosomes?
Protein creation
What process occurs in chloroplasts?
Photosynthesis
What is the primary function of mitochondria?
Respiration and metabolic processes
What role do peroxisomes play in plant cells?
Photorespiration
What is the function of vacuoles?
Storage
What is the role of the endoplasmic reticulum?
Communication and transport
List the types of plant tissues.
- Ground
- Dermal
- Vascular
What are parenchyma cells characterized by?
Living, can divide; involved in regeneration, photosynthesis, storage, secretion
What are collenchyma cells known for?
Living with thick walls; provide flexibility and growth
Creates the stringiness of celerly
What are sclerenchyma cells?
Dead with thick walls; provide defense and structure
Creates the gritty texture of pears
What is the role of guard cells?
Regulation of stomata for gas exchange
What are trichomes in plant tissues?
Defense, reduce water loss, lower temperature, absorption, secretion
What is the cuticle’s function in plant tissues?
Excretion of wax to reduce water loss
What is phloem responsible for?
Food-conducting tissue
Sieve-tubes throughout the plant
What are the functions of xylem?
Conducting water from the roots up.
Organelles that are specific to plants cells.
-Cell Wall
-Vacuoles
-Chloroplast
Ground Tissues
-Parenchyma
-Collenchyma
-Sclerenchyma
Vascular Tissues
-Phloem
-Xylem
What are Plant Hardiness Zones used for?
To inform the public on what to grow
Plant Hardiness Zones are based on climate and temperature data.
What do Floristic Regions group by?
Similar plant families and species
They focus on areas of endemism and evolution.
Define Biomes.
Large areas of land that share similar climate, vegetation, and animal life
Biomes focus on dominant vegetation and are described by environmental factors.
What environmental factors describe Biomes?
Temperature and precipitation
These factors influence the types of vegetation and animal life found in a biome.
What is the primary enzyme used in photosynthesis to convert CO2 into sugars?
Rubisco
Rubisco acts as a catalyst in the Calvin Cycle.
What does RUBP stand for?
Ribulose bisphosphate
RUBP is the primary acceptor of CO2 in the Calvin Cycle.
What are the three main processes that occur during photosynthesis?
Absorption of photons, light reactions, dark reactions
The light reactions include Photosystem II and Photosystem I, while the dark reactions involve the Calvin Cycle.
What type of plants utilize the C3 pathway?
Cool Season plants
The C3 pathway is characterized by the Calvin Cycle occurring in mesophyll cells.
What distinguishes C4 plants from C3 plants?
C4 plants fix CO2 using PEPC and Rubisco
They occur in mesophyll and bundle sheath cells, and utilize a 4-carbonic acid.
What is the Calvin-Benson Cycle?
A series of reactions in photosynthesis where CO2 is fixed into organic molecules
It primarily produces glucose using ATP and NADPH.
Fill in the blank: _______ is the primary energy source of the cell.
ATP
True or False: Photorespiration occurs during photosynthesis.
True
Photorespiration can reduce the efficiency of photosynthesis under certain conditions.
What are the roles of NADPH and NADP+ in photosynthesis?
NADPH is an electron donor; NADP+ is the oxidized form of NADPH
These molecules play critical roles in the light-dependent reactions.
What does oxidation refer to in the context of photosynthesis?
Removal of a hydrogen
Oxidation is part of the process in converting light energy into chemical energy.
What is the primary pigment involved in photosynthesis?
Chlorophyll a
Chlorophyll a plays a crucial role in the photosynthetic process by absorbing light energy.
What is the function of chlorophyll b in photosynthesis?
Accessory pigment
Chlorophyll b helps in capturing light energy and transferring it to chlorophyll a.
What happens to chlorophyll’s absorption beyond approximately 720 nm?
No absorption by chlorophyll
Chlorophyll is ineffective at absorbing light beyond this wavelength.
What is Kranz anatomy?
Bundle sheath cells surrounding the vascular bundle
Makes it easier for glucose from calvin cycle to enter the phloem
This anatomical feature is characteristic of C4 plants.
What is photorespiration?
O2 is grabbed during the Calvin Cycle, using ATP and NADPH to create CO2, considered a waste of energy
Photorespiration occurs when the enzyme Rubisco reacts with O2 instead of CO2.
What is the light compensation point?
Irradiance level at which CO2 assimilation in photosynthesis equals CO2 production in respiration
This point indicates the minimum light level needed for photosynthesis to occur.
What defines the light saturation point?
Range of irradiances over which CO2 assimilation is maximal and insensitive to irradiance levels
Beyond this point, increased light does not enhance photosynthesis.
What are sun and shade leaves?
Sun leaves have higher light saturation points, while shade leaves have lower light compensation points and faster photosynthesis in low light
Different leaf types adapt to their light environments.
What is photoinhibition?
A condition where excessive light leads to decreased photosynthesis
It can be dynamic or chronic, with reactive oxygen species (ROS) as a contributing factor.
What role do carotenoids play in plants under high light conditions?
Help absorb extra energy and assist in non-photochemical quenching
Carotenoids protect plants from damage caused by excess light.
Which proteins make up the majority of leaf nitrogen?
Proteins of the Calvin Cycle and Thylakoids
These proteins are critical for the photosynthetic process.
How does temperature affect photorespiration?
High temperatures increase photorespiration due to lower CO2 solubility
Conversely, low temperatures decrease electron transport and phloem loading.
What are CAM plants?
Plants that utilize Crassulacean Acid Metabolism, characterized by high water use efficiency and stomata that open at night
These adaptations help CAM plants survive in arid environments.
Alternative Oxidase
-Less ATP
-Creates ATP if other ATP pathway is blocked
Group that aids is essential for amino acids, nucleic acids, and enzymes.
Group 1
Nitrogen and Sulfur
Group that helps reinforce cell walls and membranes
Group 2
Phosporus, Boron, and Silicon
Group that helps with enzyme activation and photosynthesis
Group 3
Potassium, calcium, magnesium, chlorine, manganese, and sodium
Group responsible for enzymes and nitrate fixation
Group 4
Iron, Molybdenum, Zinc, Copper, and Nickle
Cohesion
The negative to positive force of water molecules
Adhesion
The force between the xylem wall and the water molecules
Xylem Cavitation
When it becomes drier, tension in the xylem becomes high. Water colum can break
