Biology Basics: Cells and Life Processes

Study Notes

Life Processes

The 7 key life processes are: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition

Cellular Structure and Function

The smallest unit of life is the cell
Sub-cellular structures common to plant and animal cells: nucleus, cytoplasm, cell membrane, and mitochondria
Plant cells have additional structures: chloroplasts, permanent vacuole, and cell wall
Nucleus: contains genetic information and controls the cell
Mitochondria: releases energy through respiration
Cell membrane: controls movement of substances in and out of the cell
Cytoplasm: where most chemical reactions take place
Chloroplasts: contain chlorophyll, which absorbs light for photosynthesis
Permanent vacuole: stores cell sap, keeping the cell turgid
Cell wall: strengthens the cell

Microscopy

To view a sample using a light microscope: place the slide on the stage, use the lowest power objective lens, move the stage away from the objective lens, and use the focusing wheel
Importance of a thin sample: light needs to pass through it
To improve focus: use the course or fine focus wheel
To adjust for higher magnification: change the objective lens
Total magnification calculation: magnification of objective lens × magnification of eyepiece lens
Iodine is a stain used to make cell parts more visible
Observable sub-cellular structures in an onion cell: nucleus, cell membrane, and cytoplasm

Surface Area and Diffusion

The rate of diffusion increases with a larger surface area

Kingdoms and Cellular Structure

The 5 kingdoms: Animal, Plant, Fungi, Protoctists, and Prokaryotes
Bacterium cell structures: cell wall, cell membrane, cytoplasm, single loop of DNA, and plasmid DNA
Hierarchy of structure in a multicellular organism: cells, tissues, organs, organ systems, and organism

Human Body Systems

Circulatory System

Function: to transport substances around the body to and from cells
Structures: heart, arteries, veins, capillaries, and blood
Blood components: red blood cells, white blood cells, plasma, and platelets
Red blood cell adaptations: biconcave shape, no nucleus, and contain hemoglobin
Heart function: pumps blood to and from the lungs and body

Digestive System

Function: breaks down food and absorbs nutrients into the blood
Structures: mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus
Stomach function: churns and breaks down food into smaller pieces, mixes with hydrochloric acid
Small intestine function: absorbs small food particles into the blood
Large intestine function: absorbs water into the body

Respiratory System

Function: exchanges gases (oxygen and carbon dioxide)
Trachea function: carries air to and from the lungs
Adaptation of ciliated cells: hair-like cilia
Function of ciliated cells in the trachea: moves dust and mucus away from the lungs
Air sacs in the lungs are called alveoli
Alveoli function: exchange gases (oxygen and carbon dioxide)

Plant Organs

Examples of plant organs: flower, leaves, shoot, roots

Description

Test your knowledge of the fundamental concepts in biology, including the 7 key life processes, cell structures, and their functions. Learn about the characteristics of plant and animal cells and how they differ.