Roots, Stems, Leaves & Tissue Systems

• This booklet provides summary notes to guide study
• Students should review all assigned units and resources for full preparation
• This booklet does not cover all ID questions

Study Guidelines

• Divide study sessions based on each KPI
• Review the summary notes and attempt all practice questions
• Use this booklet as a supplementary guide alongside textbook, notes, and additional classroom resources

Roots, Stems, Leaves & Tissue Systems

• Seed plants have three principal organs: root, stem, and leaf
• Roots anchor plants and absorb water and nutrients
• Stems support the plant, transport nutrients, and provide defense
• Leaves conduct photosynthesis and gas exchange

Plant Tissue Systems

• Plants have three main tissue systems: dermal, vascular, and ground
• Dermal tissue is the protective outer layer, consisting of the epidermis in young plants
• The epidermis is often covered by a waxy cuticle that prevents water loss
• Vascular tissue supports the plant and transports water and nutrients
• Xylem is water-conducting tissue with tracheids and vessel elements arranged end-to-end
• Phloem carries dissolved nutrients with sieve tube elements arranged end-to-end, supported by companion cells
• Ground tissue produces/stores sugars for support
• Parenchyma cells have thin cell walls and a large central vacuole
• Collenchyma cells have strong, flexible cell walls for support
• Sclerenchyma cells have thick, rigid cell walls for strength
• Meristems are regions of undifferentiated cells where mitosis produces new cells
• Apical meristems facilitate primary growth at the tips of stems and roots
• Floral meristems produce flower tissues

Leaf Structure and Function

• Leaf structure is optimized for light absorption and photosynthesis
• Most leaves have a flattened blade attached to the stem by a petiole; they consist of three tissue systems
• Leaves are covered by epidermis and a waxy cuticle limits water loss
• Vascular tissues are connected to stem vascular tissues
• Xylem and phloem form leaf veins
• Photosynthesis occurs in the mesophyll, which has two layers: palisade and spongy
• Palisade mesophyll is located beneath the upper epidermis and absorbs light
• Spongy mesophyll is a loose tissue with air spaces that connect to the exterior via stomata
• Stomata allow diffusion of carbon dioxide, water, and oxygen

Gas Exchange and Homeostasis

• A plant's control of gas exchange is a key part of homeostasis
• Leaves use stomata in spongy mesophyll to exchange gases with the air
• Plants maintain homeostasis by opening stomata enough for photosynthesis without losing excess water
• Guard cells are specialized cells that control the opening/closing of stomata based on conditions
• Abundant water leads to increased water pressure in guard cells, causing the stoma to open
• Scarce water leads to decreased water pressure in guard cells, causing the stoma to close

Plant Hormones and Tropisms

• Tropisms are growth responses to environmental stimuli, causing stems/roots to bend
• Phototropism is a response to light
• Gravitropism is a response to gravity
• Thigmotropism is a response to touch

Plant Response to Seasonal Changes and Dormancy

• Photoperiod (day and night length) is an environmental stimulus that changes with the seasons
• Phytochrome is a plant pigment that responds to the photoperiod
• Some plants flower when night length exceeds a critical duration (short-day plants)
• Others flower when daylight period is longer than a certain length (long-day plants)
• Photoperiodism is the plant's response to day/night length
• Winter dormancy preparations include leaf loss, formation of scales around buds, and photosynthesis shutdown

Animal Characteristics

• Animals are heterotrophs that obtain nutrients by eating other organisms
• Animal bodies are multicellular
• Animal cells are eukaryotic cells that lack cell walls

Animal Body Plans

• Animal body plans are based on structural and developmental characteristics
• Levels of organization proceeds from cells to tissues to organs to organ systems
• Radial Symmetry involves body parts arranged around a central axis
• Bilateral Symmetry involves left and right halves that mirror each other, allowing for directional movement
• Embryological development involves differentiation into three germ layers: endoderm, mesoderm, and ectoderm
• Endoderm develops into linings of digestive and respiratory tracts
• Mesoderm gives rise to muscles, circulatory, reproductive, and excretory systems
• Ectoderm produces sense organs, nerves, and the outer skin layer
• Segmentation is the division of the body into repeated parts in bilaterally symmetrical animals
• Cephalization is the concentration of sense organs/nerve cells at the anterior (head) end
• Limb formation involves external appendages on both body sides in segmented and bilaterally symmetrical animals

Human Body Organization

• The organization levels are cells, tissues, organs, and organ systems
• Cells are the basic structural/functional units
• Tissues are groups of similar cells performing a single function
• Organs are groups of different tissues working together
• Organ Systems are groups of organs performing related functions
• Bone, blood, and muscle cells are cell examples
• Epithelial, Connective, Nervous and Muscle tissues are tissue examples
• Heart, brain, liver, lungs kidneys and eye are organ examples
• Digestive, Respiratory and Nervous system are system examples

Human Body Homeostasis

• Homeostasis maintains constant internal physical and chemical conditions
• Feedback inhibition(negative feedback) is when a stimulus triggers a response that opposes the original stimulus
• Body temperature is an example of feedback inhibition

Digestive System

• Ingestion is the process of taking food into the mouth
• Digestion is the breakdown of food by mechanical and chemical means
• Absorption is when small molecules of food are absorbed by the cells of the small intestine called Villi
• Elimination is when undigested material is eliminated from the body as feces

Excretory System

• Kidneys remove waste from the blood
• Cleansed blood exits via the renal vein
• Nephrons are the functional units of the kidneys
• Filtration involves fluid passage to remove wastes.
• Blood filtration in nephrons happens in the glomerulus,
• Bowmans capsule encloses each glomerulus.
• Fluids and wastes that from the capillaries are called Filtrate(water, sugar, salts, amino acids)
• Reabsorption is material entering bowman's capsule which is transported back into circulations
• Urine excretion involves fluid in the tubule collected and sent to the ureter

Sequence of Blood Flow

• Pulmonary and systemic circulations follow a loop to ensure oxygenation and distribution
• Systemic Circulation (Oxygenated Blood):
• Left atrium receives oxygenated blood from lungs through veins
• Blood goes through the mitral valve into the left ventricle
• Left ventricle pumps oxygenated blood to the aorta
• Aorta distributes the oxygen to the body while tissues pick up CO2
• Pulmonary Circulation (Deoxygenated Blood):
• Deoxygenated blood goes into the right atrium from the vena cava
• Flows through the tricuspid valve into the right ventricle.
• The right ventricle pumps to the lungs via arteries,
• the gases exchanged for oxygen before returning to veins back to the left artium

Vessels Structure Function

• Arteries, capillaries, and veins
• Arteries deliver blood from heat to tissues, most arteries carry blood but the
• all walls of the arteries constist of Connective tissue, smooth muscle and endothelium
• The narrowest vessels are cells
• The capillaries which connect to capillaries
• Their function is Oxygen/Nutrients to different parts of the body

Blood components

• Erythrocytes, which transport both O and Co2 while using hemoglobins for back up
• Leukocytes protect against diseases
• Thrombocytes prevents excessice bleeding by releasing protein plugs
• Plasma functions to release nutrients and waste, plus its water-based in structire

Lymphatic

• Lymph vessel are connected to both lymph nodes (arm pit regions )
• And is located near the spleen/tonsides/ thymus

The Breath

• Respiration relates to gases released and entering from the body
• The system includes the nose/larnx/trahea/ bronchi
• Air filters through the nose while getting moister to prevent to many dusty materials
• Epiglottis functions while air enters the trachea
• Branchioles also have dust collectors
• Alevoil exchange gases
• Expansion and contracting while facilitating breathing due the surface area, and rich blood

Nerve Impulse

• Each nervous system is transmited via cells
• which is categorized as
  • To senses
  • To brain muscles
  • Sends commands
• When at rest they maintain a neg charge
• Neurons fire to negative chage restored , sodium moves positive , with k

Muscle

• Somatic involves volunteer
• Autonomis is actions not controlled, by heart or reflex