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Protists and Fungi
Protists: ● Kingdom Protista
Characteristics: ● Usually single celled organisms ● Live in moist environments ● Vary in the ways they move and obtain energy
Obtain Energy: ● Animal-like: ingest or absorb food after capturing it or trapping it● Plant-like: produce food through photosynthesis ● Fungus-like: obtain their food by external digestion either as decomposers or parasites ● Some are autotrophic and heterotrophic
Movement (locomotion): ● Flagellum (flagella): long whip-like tail used to move and capture food
○ Example: Euglena ● Cilia: small hair-like projections on the surface of the cell
○ Example: Paramecium ● Pseudopod (false foot): finger like projection of the cell membrane and cytoplasm
○ example : Amoeba Fungi
● Kingdom Fungi ● Microorganisms (ex. Yeast and mold) and multicellular organisms (ex. mushrooms)
Obtain Energy: ● Saprophytic: fungi that get their energy from decaying organisms● Parasitic: fungi that feed on other living organisms(host) and harm the host ● Symbiotic: fungi that feed on other living organisms (host) but do not harm the host
○ In some cases the host benefits from the fungi
Movement: ● Not mobile in most cases● Can be categorized based on their fruiting structures
Fungi and External Stimuli
● Fungi are able to respond to information from their environment to ensure survival of the organism
Stimuli:● Phototropism: growing in response to light ● Gravitropism: growing away from gravity
○ As fungi matures they tend to display negative gravitropism
Hyphae: ● Fungi use this due to their lack of a root system● Long fibrous strands that allow the fungus to obtain water/nutrients ● Hyphae growth influenced by stimuli
○ Will grow toward a food source, water or reproductive units of other fungi
Vocabulary: ● Mycelium: a collective mass of hyphae ● Stimulus: thing or event that evokes a specific functional reaction ● Negative Gravitropism: grows in the opposite direction of gravity ● Positive Gravitropism: grows in the direction of gravity
Nonvascular and Vascular Plants
Plants are classified into two major groups based on their internal structures. ● Vascular● Nonvascular
Vascular Plants ● Largest group in Kingdom Plantae (Plant Kingdom) ● Well developed system for transporting food and water
○ Have true roots, stems and leaves ● Have tube like structures that provide:
○ Support ○ Circulate food and water
● Xylem: transport water and minerals from the roots to the rest of the plant ● Phloem: Transport food from the leaves to the rest of the plant ● Examples: trees, shrubs and dandelions
Nonvascular Plants ● Do not have a well-developed system for transporting water and food
○ Do not have true roots, stems and leaves ● Obtain nutrients directly from the environment ● Distribute it from cell to cell throughout the plant ● These are small plants that are close to the ground● Examples: mosses, liverworts, and hornworts
Photosynthesis
● Process where plants make their own food ● Chlorophyll: absorbs sunlight and gives plants the green color
○ Located in the thylakoids ● Bottom of leave contains stomata (pores) which allow gases to enter and leave the plant
Respiration
Notes: ● Necessary to perform life functions ● Uses the sugar that is produced during photosynthesis ● Respiration releases the energy from food
Transpiration Notes:
● Plants water through their leaves ● Water is absorbed through the roots ● Guard Cells
○ Used to control the stomata and the process of transpiration ○ Guard cells allow for the stomata to be open or closed by changing their position ○ When the stomata is open gases can flow in and out of the plant ○ When the stomata is closed water cannot escape
Structural Adaptations for Defense
Structures allow plants to protect themselves from threats that could potentially kill the plant.
Examples: ● Thorns defend plants from being eaten by some animals● Fruits and leaves with poisons to prevent them from being eaten● Ability to close leaves when touched (thigmotropism)
Thorns
Thigmotropism
Structural Adaptations for Survival
Structures that allow plants to survive in their habitats when conditions are not suitable
Examples: ● Leaves function as the site of photosynthesis, respiration and transpiration ● Stems support the plant, hold the leaves up to the light and function as food storage
sites ○ Xylem: transports water from the roots to the leaves and other parts ○ Phloem: transports food made in the leaves to growing parts of the plant
● Roots anchor the plant in the ground○ Absorb water/nutrients from soil ○ Store extra food for the plant ○ The larger amount of surface area = more water/nutrients can be absorbed ○ Root hairs can increase surface area
● Types of Roots: ○ Fibrous Roots
■ Several main roots branching off to form a mass of roots ■ Examples: grass, corn, some trees
○ Taproots ■ One large main root with smaller roots branching off ■ Examples: carrots, dandelions
● Seeds are specialized structures to allow them to be dispersed by wind, water or animals
● Seed coat protects the embryo from injury and drying out
Structural Adaptations for Reproduction
Parts of the flowering plant that function in reproduction include:
Flowers: ● Produce seeds ● Contain both male and female organs needed to produce new flowers ● Petals are colorful or have a scent to attract insects and animals
Stamen: ● Male organ of a flower that has an anther on a stalk (filament) ● Anther produces the pollen that contains the sperm cells
Pistil ● Female organ of the flower containing:
○ Ovary: contains ovules where the egg cells are produced ○ Stigma: sticky top where pollen grains land ○ Style: stalk down which the pollen tube grows after pollination has taken place
Seed ● Ovule contains the fertilized egg (embryo) from which new plants are formed ● Fruit that is formed from the ovary often protects them
Plants Respond to their Environment
Responses vary depending on the specific environmental stimulus
Stimulus: change in the environment that causes a response or reaction
Temperature: ● Temperature and day length can be used to manipulate flowering ● Temperature alone can influence flowering ● Some plants require exposure to cold temperatures to force the bulb to mature ● Many plants require a daily temperature change to ensure that photosynthesis and
respiration occur at their optimal temperatures ○ This maximizes plant growth
● Some conditions push a mature plant/seed to become dormant (inactive) ● Dormancy allows for species to survive in particular environments
○ Ensures that seeds will germinate when conditions are favorable for the survival of the seedlings
○ Example: leaves fall from trees prior to winter and the leaf buds do not open until spring
Dormancy: a period of time when the growth or activity of a plant or seed stops due to changes in temperature or amount of water
Tropisms:
Definition: plants responding to changes in their environment by growing their stems, roots, or leaves toward/away from a stimulus
Examples: ● Phototropism: plant grows or moves in response to light● Gravitropism: plant grows or moves in response to gravity
○ Also known as geotropism ● Hydrotropism: plant grows or moves in response to water ● Thigmotropism: plant grows or moves in response to touch
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