Plants - Structure and Function Review PDF

Review Plants - Structure and Function in Review Structure of Plants Types of Tissues: Meristematic Tissues: an unspecialized plant cell that gives rise to a specific specialized cell, can be found in root tips, shoots, buds, and any place where new growth occurs, function of this tissue is to carr...

Review Plants - Structure and Function in Review Structure of Plants Types of Tissues: Meristematic Tissues: an unspecialized plant cell that gives rise to a specific specialized cell, can be found in root tips, shoots, buds, and any place where new growth occurs, function of this tissue is to carry out cell division (mitosis) for cell growth Dermal Tissues: outermost layer, they protect the plant from the elements, herbivores, and insects, epidermal root cells form root hairs to absorb water and minerals from the soil, produce a waxy waterproof cuticle Vascular Tissues: a system of internal tubes that connects the roots and the leaves There are two types of vascular tissue: ​ Xylem: consists of non-living cells –its function is to transport water and minerals from the roots to the leaves ​ Phloem: consists of living cells –its function is to transport nutrients, such as carbohydrates, from the leaves to areas where they are needed for growth and cell functions, or to the roots for storage. Ground Tissue: located between the dermal and vascular tissues and performs several functions, ground tissue is made up of cells that: -​ contain chloroplasts to perform photosynthesis (in leaves). -​ provide support for the plant’s body (in stems) -​ store nutrients (in roots) Structure and Function: Roots ​ Structure ○​ Root Hairs: increase surface area for water and mineral absorption  ​ increase surface area for the osmosis of water into the root, and the absorption of minerals into the root ○​ Meristem: the region where new cells are produced ○​ Root Cap: protects the growing root ​ Function ○​ anchor a plant in soil or to an object –helps keep plant from being washed away during a heavy rainstorm or from being uprooted by strong winds ○​ absorbs water and minerals from the soil –to be transported to where they are needed in the rest of the plant ○​ stores water, nutrients, and carbohydrates (sugar) -that are produced in green leaves and green stems of plants Stems ​ Structure ○​ Most plant stems have a system of internal tubes (vascular tissue) that connects the roots and the leaves. There are two types of vascular tissue: ​ Xylem: non-living cells –its function is to transport water and minerals from the roots to the leaves ​ Phloem: living cells –its function is to transport nutrients, such as carbohydrates, from the leaves to areas where they are needed for growth and cell functions, or to the roots for storage. ​ Function ○​ provide support and a place for roots, leaves, buds, and flowers to attach ○​ allow a plant to increase in size or in mass ○​ transport water and minerals from the roots to the leaves ○​ transport carbohydrates produced by photosynthesis in leaves to other parts of the plan Leaves ​ Structure  ○​ Cuticle: waxy layer; covers upper surface-protects leaf against water loss while letting light pass through ○​ Vascular Tissue: transports water, nutrients, and sugar made of xylem and phloem vascular tissue ○​ Mesophyll: divided into two sections ​ Palisade mesophyll: is the upper layer of the mesophyll tissue, contains a high number of chloroplasts, making it the primary site of photosynthesis, Arranged in columns to maximize light absorption. ​ spongy mesophyll: layer is located below the palisade layer and above the lower epidermis, Composed of loosely packed, irregularly shaped cells, Contains fewer chloroplasts than the palisade layer, has large intercellular air spaces that facilitate gas exchange. ○​ Guard Cells: cells that open and close the stomata –conserve water by preventing excess water transpiration ○​ Stomata: openings in the leaf’s surface; when open: ​ GAS EXCHANGE: allows CO2 in and O2 out of the leaf ​ TRANSPIRATION: allows excess H2O out of the leaf ​ Function ○​ most important function is to capture sunlight for photosynthesis –have a broad, flat surface for increased light absorption ○​ move carbon dioxide in and oxygen out of the leaves through the stomata ○​ the evaporation of water from leaves creates a force (transpiration) that helps to move water through the xylem ​ The structure of a leaf supports gas exchange by having stomata (pores) on its surface, controlled by guard cells, which regulate the movement of gases like carbon dioxide (CO₂) and oxygen (O₂). The spongy mesophyll layer contains air spaces that allow gases to diffuse easily between the stomata and photosynthetic cells. The leaf's thin, broad shape maximizes surface area for gas exchange and light absorption, while vascular tissues  (xylem and phloem) support the transport of water and nutrients essential for photosynthesis. Chloroplasts: site of photosynthesis in eukaryotic cells, only present in photosynthetic cells like plant cells and algae Photosynthesis: is a biological process by which green plants, algae, and certain bacteria convert light energy from the sun into chemical energy stored in organic molecules such as glucose. This process primarily occurs in the chloroplasts of plant cells. It involves a series of chemical reactions that use light energy, carbon dioxide (CO₂), and water (H₂O) to produce glucose (C₆H₁₂O₆) and oxygen (O₂) as by-products, contains Chlorophyll is a pigment necessary for photosynthesis 6CO2 + 6H2O → C6H12O6 + 6O2 Structure Of Angiosperm (Flowering Plants) ​ Root System ○​ Anchors the plant in the soil and absorbs water and nutrients. (fibrous vs taproot) ​ Shoot System ○​ Consists of stems, leaves, flowers, and fruits. ​ Vascular System ○​ (Xylem and Phloem) ​ Seeds Monocots vs Dicots Monocots Dicots  ​ Start with one seed leaf ​ Start with two seed leaves (cotyledon) (cotyledons) ​ Parallel leaf venation ​ Net or reticulate leaf venation ​ Flower Parts in multiples of 3 (3, ​ Flower Parts in multiples of 4-5 6, 9, etc) (4, 5, 8,10, etc) ​ Fibrous root system (many thin ​ Taproot system (one main root roots) with smaller branches) ​ No secondary growth ​ Secondary growth possible ​ ex grasses ​ ex flowering plants Plants in Their Environment Transpiration: The transport of Water and Nutrients, the evaporation of water molecules from a plant's shoot system is the key force driving the upward movement of water and dissolved minerals in the stem, dry air, heat and wind cause transpiration occurs in three stages: 1)​ from the soil into the roots 2)​ from the roots to the stem 3)​ from the stem to the leaves This happens by two different processes: 1.​ water enters the root by osmosis, the diffusion of water from an area of high concentration to an area of low concentration 2.​ nutrients enter the root by active transport, which requires the use of ATP energy Once water molecules and nutrients enter the root hair, they travel to the vascular tissue, the xylem Osmosis: is the movement of water molecules across a semi-permeable membrane from an area of (high water concentration) to an area of (low water concentration), aiming to equalize the concentration on both sides. Diffusion: is the process by which molecules or particles move from an area of higher concentration to an area of lower concentration until they are evenly distributed. Step-by-Step Process of Water Movement Through Transpiration ​ Transpiration Initiates: ○​ Water evaporates from leaves → Pressure decreases in leaves. ​ Tension Forms: ○​ Decreased pressure creates tension in xylem water columns. ​ Water is Pulled Up: ○​ Tension draws water upward from roots through xylem. ​ Cohesion Maintains Column: ○​ Water molecules stick together, maintaining the column. ​ Adhesion Anchors Water: ○​ Water molecules stick to xylem walls, aiding movement. ​ Continuous Flow: ○​ Replacement of lost water ensures ongoing transpiration and nutrient transport. Cohesion: Water molecules stick to each other because of hydrogen bonding, creating a continuous chain. Adhesion: Water molecules stick to the walls of the xylem vessels, supporting the column and preventing it from collapsing. Translocation: transport of glucose, and other organic molecules through the phloem of a plant Growth Primary growth: includes all growth of apical meristems and first-year growth of lateral meristems. Secondary growth: includes all growth from lateral meristems occurring after the first year. Alteration of Generations: life cycle of a plant, alternate between two different life stages, in their life cycle; a haploid stage (n) called a gametophyte, and a diploid stage (2n) called a sporophyte Tropisms: Short-term responses to the environment ​ Phototropism: a growth response towards sunlight ​ Gravitropism or Geotropism: a growth response to gravity –plant roots generally grow downward towards the force of gravity, whereas a plant’s stem usually grows upward against the force of gravity. ​ Thigmotropism: a growth response to contact with an object or even wind, ex. vines that twist around a fence Adaptation: After many generations, when all members of a plant species have a variation Example: In the biome Tundra it has short summers, long extremely cold winters, and 15-25 cm of precipitation/per year so the plants grow close to the ground due to the lack of nutrients in the soil and to help avoid freezing Vascular Bundle / Vein: A vascular bundle (commonly seen as "veins" in leaves) is a part of the vascular system in plants, composed of xylem and phloem tissues. Cortex: Stores nutrients; facilitates transport; offers support. Cambium: Produces new xylem and phloem; aids in growth. Pith: Stores nutrients and water; supports the plant stem. Vascular plants: have a well-developed vascular system composed of xylem and phloem, which transport water, minerals, and nutrients throughout the plant. Nonvascular plants: lack a vascular system and rely on diffusion and osmosis to move water and nutrients through the plant. Practice Test  Practice Test Multiple Choice Questions (30 Questions) 1.​ What is the primary function of meristematic tissue? a) Photosynthesis b) Cell division for growth c) Nutrient transport d) Water storage 2.​ Which tissue is responsible for transporting water in plants? a) Phloem b) Xylem c) Cortex d) Cambium 3.​ The outermost layer of a plant that protects against water loss and injury is called: a) Ground tissue b) Dermal tissue c) Vascular tissue d) Cambium 4.​ What is the function of the root hairs? a) Support the root b) Protect the root tip c) Increase surface area for absorption d) Store nutrients 5.​ What structure protects the growing tip of a root? a) Cortex b) Root cap c) Cambium d) Epidermis  6.​ In vascular plants, phloem is primarily responsible for: a) Transporting water and minerals b) Transporting sugars and nutrients c) Producing new cells d) Anchoring the plant 7.​ What is the main function of the cuticle on a leaf? a) Photosynthesis b) Protect against water loss c) Gas exchange d) Transport nutrients 8.​ Which structure opens and closes to regulate gas exchange in leaves? a) Stomata b) Guard cells c) Cuticle d) Mesophyll 9.​ The spongy mesophyll in a leaf is involved in: a) Storing nutrients b) Transporting water c) Allowing gas diffusion for photosynthesis d) Protecting the epidermis 10.​What process moves water from the soil into plant roots? a) Active transport b) Diffusion c) Osmosis d) Transpiration 11.​Which of the following is true for monocots? a) Net-like venation in leaves b) Taproot system c) Flower parts in multiples of 3 d) Secondary growth possible 12.​What type of venation do dicots have in their leaves? a) Parallel b) Spiral c) Net-like d) Random 13.​Transpiration is defined as: a) The movement of sugars in the phloem b) The evaporation of water from plant leaves c) The process of photosynthesis d) The transport of minerals in xylem 14.​What is the role of cohesion in transpiration? a) Prevents water loss b) Helps water molecules stick to each other c) Transports sugars d) Aids in photosynthesis 15.​The region in the root where new cells are produced is called the: a) Cortex b) Cambium c) Meristem d) Pithre 16.​Which tissue in stems stores nutrients and provides support? a) Xylem b) Ground tissue c) Phloem d) Cambium 17.​What is the primary function of the vascular bundle? a) Store nutrients b) Provide structural support c) Transport water, minerals, and nutrients d) Produce new cells 18.​Which structure is not part of the shoot system? a) Leaves b) Flowers c) Roots d) Stems 19.​What is the term for the growth response of plants to sunlight? a) Gravitropism b) Thigmotropism c) Phototropism d) Hydrotropism 20.​What is the function of guard cells? a) Transport water in the xylem b) Regulate the opening and closing of stomata c) Store water d) Perform photosynthesis 21.​What part of the vascular system stores nutrients in stems? a) Cortex b) Cambium c) Pith d) Phloem 22.​What type of vascular tissue is composed of dead cells? a) Xylem b) Phloem c) Cortex d) Cambium 23.​The evaporation of water from leaves is called: a) Transpiration b) Translocation c) Diffusion d) Osmosis 24.​Which tissue produces new xylem and phloem in stems? a) Cambium b) Cortex c) Epidermis d) Pith 25.​The life cycle of plants alternates between two stages: a) Haploid and triploid b) Haploid and diploid c) Diploid and tetraploid d) Haploid and pentaploid 26.​The primary function of stomata is: a) Gas exchange and transpiration b) Transport nutrients c) Store water d) Prevent water loss 27.​Which plant structure anchors the plant in soil? a) Leaves b) Stems c) Roots d) Flowers 28.​What is a key characteristic of dicots? a) Parallel venation b) Fibrous roots c) Flower parts in multiples of 4-5 d) No secondary growth  29.​Active transport in roots is used to: a) Absorb water b) Absorb nutrients c) Transport oxygen d) Perform photosynthesis 30.​What is the waxy layer on the surface of leaves? a) Mesophyll b) Cuticle c) Guard cells d) Stomata Fill-in-the-Blank Questions (5 Questions) 1.​ The ________ tissue transports sugars and nutrients throughout the plant. 2.​ Water enters the root through ________, which is the diffusion of water from high to low concentration. 3.​ The process by which water evaporates from plant leaves is called ________. 4.​ ________ helps water molecules stick to each other, while ________ helps them stick to xylem walls. 5.​ The waxy layer on leaves that prevents water loss is called the ________. Short Answer Questions (2 Questions) 1.​ Explain how the structure of a leaf supports photosynthesis and gas exchange. 2.​ Compare the structure and function of xylem and phloem.  Answer Key Multiple Choice Answers 1.​ b 2.​ b 3.​ b 4.​ c 5.​ b 6.​ b 7.​ b 8.​ a 9.​ c 10.​c 11.​c 12.​c 13.​b 14.​b 15.​c 16.​b 17.​c 18.​c 19.​c 20.​b 21.​c 22.​a 23.​a 24.​a  25.​b 26.​a 27.​c 28.​c 29.​b 30.​b Fill-in-the-Blank Answers 1.​ Phloem 2.​ Osmosis 3.​ Transpiration 4.​ Cohesion; adhesion 5.​ Cuticle Short Answer Answers 1.​ Leaf structure: Stomata regulate gas exchange, allowing CO₂ to enter for photosynthesis and O₂ to exit. The spongy mesophyll facilitates gas diffusion, while the broad surface maximizes sunlight absorption. Vascular tissues transport water and nutrients to support photosynthesis. 2.​ Xylem vs. Phloem: Xylem is made of dead cells and transports water/minerals from roots to leaves. Phloem is composed of living cells and transports sugars/nutrients to areas of growth or storage.