Revision for Plant and Animal Systems

Cells: Basic unit of life. Tissues: Groups of similar cells working together. Organs: Structures made of different tissues working together. Organ Systems: Groups of organs performing a major function. Organism: The complete living thing.

What are the levels of organisation from cells to organisms in multicellular organisms?

• Circulatory System: Transports oxygen, nutrients, and waste. Key organs: Heart, blood vessels.

• Respiratory System: Exchanges oxygen and carbon dioxide. Key organs: Lungs, trachea, diaphragm.

• Skeletal System: Provides support, protection, and movement. Key organs: Bones, cartilage, ligaments.

What are the key organs and functions of the body systems on this sheet?

• Plasma: Liquid part that carries cells and nutrients.

• Red Blood Cells: Cells that transport oxygen.

• White Blood Cells: Cells that fight infection and disease.

• Platelets: Cell fragments that help blood clot.

What are the main components of blood?

• Red Blood Cells: Biconcave shape increases surface area for oxygen. No nucleus allows more space for hemoglobin.

• White Blood Cells: Can change shape to engulf pathogens. Produce antibodies to destroy invaders

How does the structure of different blood cells connect to their function?

• Arteries: Carry blood away from the heart.

• Capillaries: Allow exchange of materials with tissues.

• Veins: Return blood back to the heart.

What is the purpose of the different blood vessels in the human body?

• Arteries: Thick, elastic muscular walls to withstand high pressure. Narrow lumen.

• Veins: Thin walls with a wide lumen. Contain valves to prevent backflow.

• Capillaries: Microscopic, walls are only one cell thick for fast diffusion.

How do the structure and function of arteries, veins, and capillaries compare?

Vena Cava, Right Atrium, Tricuspid Valve, Right Ventricle, Pulmonary Valve, Pulmonary Artery, Lungs, Pulmonary Veins, Left Atrium, Bicuspid Valve, Left Ventricle, Aortic Valve, Aorta

What is the path of blood flow through the vessels, valves, and chambers of the heart?

• Blood passes through the heart twice per circuit.

• Separates oxygenated and deoxygenated blood completely.

• Maintains high pressure to deliver oxygen rapidly.

Why do humans have a double circulatory system?

• Chambers: Atria are at the top; ventricles are at the bottom.

• Vessels: Arteries leave the heart; veins enter the heart.

• Valves: Sit between atria and ventricles, and at vessel exits.

How do you label the chambers, vessels, and valves of the heart?

• Right Side: Contains deoxygenated blood returning from the body.

• Left Side: Contains oxygenated blood returning from the lungs.

What is the difference in oxygen content between the areas of the heart?

• Left Ventricle: Has extra thick muscle to pump blood to the entire body.

• Heart Valves: Snap shut to prevent blood flowing backward.

• Septum: Central wall preventing blood on the left and right sides from mixing.

What are the significant functional characteristics of heart structures?

Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

Can you identify the names of the respiratory organs?

• Nasal Cavity: Warms, filters, and moistens incoming air.

• Trachea: Main windpipe leading toward the lungs.

• Bronchi/Bronchioles: Branching tubes distributing air throughout lungs.

• Alveoli: Air sacs where gas exchange occurs.

• Diaphragm: Muscle driving inhalation and exhalation.

What is the function of each respiratory organ?

• Inhalation: Nose, Trachea, Bronchi, Bronchioles, Alveoli.

• Exhalation: Alveoli, Bronchioles, Bronchi, Trachea, Nose.

What is the flow of air from inhalation through exhalation?

• Large Surface Area: Millions of tiny alveoli expand space.

• Thin Barriers: Alveoli and capillary walls are one cell thick.

• Moisture: Gas dissolves easily on moist surfaces.

• Blood Supply: Dense capillary networks maintain a steep concentration gradient.

What adaptations make gas exchange efficient in the lungs?

• Support: Creates structural framework.

• Protection: Shields vital internal organs.

• Movement: Offers levers for muscles.

• Storage: Holds calcium and minerals.

• Production: Makes blood cells in marrow.

What are the main functions of the Skeletal System?

• Compact Bone: Heavy, dense outer layer providing strength and shock resistance.

• Spongy Bone: Lightweight internal lattice reducing skeleton weight while housing bone marrow.

Why are both compact bone and spongy bone important?

• Muscles connect to bones via tendons.

• Muscles can only pull; they cannot push.

• They contract (shorten) to pull a bone across a joint.

What is the relationship between muscles and bones to cause movement?

• They work in opposition to move the forearm.

• Bending the arm (flexion): Biceps contract, triceps relax.

• Straightening the arm (extension): Triceps contract, biceps relax.

How do the biceps and triceps act as an antagonistic muscle pair?

• Ball and Socket (e.g., Shoulder, Hip): Provides a 360-degree rotational range of motion in all planes.

• Hinge Joint (e.g., Knee, Elbow): Restricts movement to a single plane (like a door opening and closing).

What is the range of motion for different joints in the body?

• They consist of multiple tissues working together for a common purpose.

• Roots: Anchor plant; absorb water and minerals.

• Stems: Provide structural support; transport materials up and down.

• Leaves: Primary site for photosynthesis and gas exchange.

• Flowers: Specialized reproductive structures for producing seeds

How are flowers, roots, stems, and leaves classified as organs?

• Xylem: Hollow tubes made of dead cells reinforced with lignin. They carry water and minerals upwards from roots.

• Phloem: Living columns of sieve tubes and companion cells. They transport sugars bidirectionally to where they are needed.

What are the structures and functions of xylem and phloem?

• Water/Minerals: Pulled upward through xylem via a continuous transpiration stream.

• Sugars/Nutrients: Translocated through phloem from source (leaves) to sink (roots/fruit)

How are nutrients and materials transported through a plant?

• Stomata are microscopic pores on leaf surfaces.

• When stomata open for carbon dioxide intake, water vapor escapes.

• This evaporation of water from stomata drives the entire transpiration pull.

What is the relationship between stomata and transpiration?

• Temperature: Higher heat increases evaporation, speeding up transpiration.

• Wind: Moves water vapor away from leaves, speeding up transpiration.

• Humidity: High moisture in the air slows down evaporation and transpiration.

• Light Intensity: Bright light opens stomata, speeding up transpiration.

How do environmental factors affect the rate of transpiration?

• Phototropism: Growth movement in response to light (stems grow toward light).

• Geotropism/Gravitropism: Growth movement in response to gravity (roots grow down, stems grow up).

• Thigmotropism: Growth movement in response to touch (climbing vines wrapping around poles).

What are the different types of tropisms in plants?

• Optimizes survival chances in a fixed location.

• Maximizes light absorption for photosynthesis (phototropism).

• Secures firm anchoring and reliable water access in soil (geotropism).

Why are plant responses (tropisms) beneficial to their survival?