Autotrophs and Heterotrophs in Biology

Autotrophs and Heterotrophs

• Autotrophs obtain glucose through self-manufacture via photosynthesis, producing their own food.

• Autotrophs use energy from the sun to convert water and carbon dioxide into glucose.

• Glucose gives plants energy and is used to make cellulose for growth and cell walls.

• Heterotrophs obtain organic nutrients by consuming autotrophs or other heterotrophs.

• Heterotrophs rely on autotrophs and other organisms for nutrition.

Plant Structures

Roots

• Anchor the plant, transport water, minerals, and sugars, and store excess nutrients.
• Function similar to our feet, helping the plant balance.

Stem

• Functions in support, conduction, photosynthesis, and storage.

Leaves

• Organs of the shoot system adapted for photosynthesis.
• Contain chloroplasts and stomata for gas exchange.

Gas Exchange

• Plants exchange gases through stomata (tiny pores) on the underside of leaves.
• Guard cells regulate stomatal opening and closing.
• Animals exchange gases through specialized respiratory organs (e.g., lungs, gills, skin).
• Cells in both plants and animals perform respiration.

Unicellular and Multicellular Organisms

• Unicellular organisms consist of one cell only.
• Examples: Amoeba, Paramecium.
• Multicellular organisms consist of multiple cells.
• Examples: humans, animals, plants.
• Cells need to communicate and coordinate to function properly.

Tissues and Organs

• Tissue: a collection of cells that perform the same function.
• Examples: muscle, nerve, connective, epithelial tissue.
• Organ: a structure that contains more than one type of tissue working together.
• Examples: heart, stomach, brain.
• Organ system: a group of functionally related organs.
• Examples: digestive system, circulatory system.

Hierarchical Structure of Organisms

• Cells: the basic unit of structure and function in living organisms.
• Cells perform various functions, such as growth, metabolism, and reproduction.
• Organelles: specialized structures within cells.
• Examples: chloroplasts, mitochondria, ribosomes.
• Tissues: a collection of cells that perform the same function.
• Examples: muscle, nerve, connective, epithelial tissue.
• Organs: a structure that contains more than one type of tissue working together.
• Examples: heart, stomach, brain.
• Organ systems: a group of functionally related organs.
• Examples: digestive system, circulatory system.

Stem Cells and Differentiation

• Stem cells: cells that have the potential to form many other cells.
• Can be totipotent, pluripotent, or multipotent.
• Differentiation: the process by which cells become specialized for a specific function.
• Involves the expression of specific genes and the formation of specialized structures and organelles.

Gas Exchange in Plants

• Stomata: tiny pores on the underside of leaves that allow for gas exchange.
• Regulated by guard cells.
• Photosynthesis: the process by which plants convert sunlight into chemical energy.
• Occurs in chloroplasts and requires carbon dioxide and water.

Leaf Structure and Photosynthesis

• Leaf structure: includes the cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, and lower epidermis.
• Each layer has a specific function, such as reducing water loss or capturing light for photosynthesis.
• Photosynthesis: occurs in chloroplasts and requires light energy.
• Produces glucose and oxygen as byproducts.

Plant Structure and Function

• A leaf's structure is adapted to increase light absorption and carbon dioxide diffusion.
• Large surface area to increase light absorption.
• Thin to minimize distance for carbon dioxide diffusion.
• Chlorophyll absorbs sunlight and transfers energy into chemicals.
• A network of veins supports the plant and carries water and carbohydrates.
• Stomata (pores mainly located on the underside of the leaf) allow carbon dioxide to diffuse into the leaf.
• Leaf adaptations: thin, transparent epidermis to allow more light...