BiologyThe study of Living Things

Characteristics of Living Things

– Made of cells– Obtain and use energy

– Grow and develop– Reproduce

– Respond to their environment– Adapt to their environment

Cells

• Make up all living things• Basic units of structure and

function• Humans are made of trillions of

cells and there are hundreds of different types.

Two Classifications of Cells

• Prokaryotic Cells – 1st form of life– No nucleus– Only form

Unicellular organisms (one celled)

– Example: Bacteria

• Eukaryotic Cells– Formed from

prokaryotes– Have a nucleus– Form unicellular

and multi-cellular organisms.

– Example: Plants and animals

Types of Living Things

• Unicellular organisms– Function by itself

without need of other cells for survival

• Bacteria• Protozoa• Unicellular algae,

fungi and yeast• pathogens

• Multi-cellular organisms– Made of many

cells that are specialized and work together to function and survive.

• Plants and animals

Cell OrganellesStructure Function

– Cell Membrane: Outer cell lining for protection

– Cytoplasm: Liquid that organelles float in

– Nucleus: Control center with DNA

– Nuclear Membrane:Surrounds and protects nucleus

– Vacuoles: Stores water and other nutrients in

plant cells

Cell Organelles

Structure Function

– Mitochondria: Produces energy (ATP)

– Ribosomes: Makes proteins

– Endoplasmic Reticulum: Transports proteins throughout cell

– Golgi Apparatus: Stores, modifies and secretes proteins

– Cell Wall: Gives Plant cells structure and support to maintain shape

Cell OrganellesStructure Function

– Chloroplast: Produces energy through photosynthesis in Plant cells

– Microtubules protein filaments involved in cell movement, shape, and cell division.

– Centrioles contain microtubules and involved in cell division.

– Lysosomes helps with animal cell digestion

– Chromosomes strands of DNA inside the nucleus.

Animal Cell

Animal Cell

Plant Cell

Plant Cells

Cells Make Tissues

• A group of similar cells working together

• 4 types:

1. Epithelial tissue 2. Nervous3. Muscle4. Connective

Epithelial Tissue

• Covers and protects underlying tissue

• Ex. - Skin

Nervous Tissue

• Sends electrical signals through the body

• Found in the brain, nerves and sense organs

Muscle Tissue

• Made of cells that can contract and relax to produce movement

• 3 Types: Skeletal, Smooth, and Cardiac

3 Types of Muscle Tissue

• Cardiac - only found in the heart

• Smooth - line the wall of structures inside the body

• Skeletal - makes the body move

Connective Tissue

• Joins, supports, protects, insulates, nourishes, and cushions organs

• Keeps organs from falling apart

ORGANS

• Two or more tissues working together

• Organs that work together make up an organ system

• The body has 12 major organ systems

Integumentary System• Skin, hair and nails• Main function is

protection• Helps regulate body

temperature• Helps remove waste

from the body• Produces Vitamin D• Receives stimuli such

as pressure, heat, cold and pain

Muscular System

• The human body contains more than 650 individual muscles

• The muscular system provides movement for the body

• Muscles can be voluntary or involuntary

3 Types of Muscle Tissue

• Skeletal Muscle – Attached to the skeleton and moves parts of the body

• Smooth Muscle – Usually involuntary and found in internal organs

• Cardiac Muscle – Only found in the heart

Skeletal System• Provides structure• Supports and

protects the body• Allows bodily

movement – attached to muscles

• Produces red blood cells– an average of 2.6 million cells each second

• Stores minerals – such as calcium and phosphorus

Skeletal System

• Bones - More than 206 bones in the human body.

• Ligaments - attaches bone to bone

• Tendons - attaches muscle to bone

• Cartilage

Circulatory/Cardiovascular System

• Heart, blood and blood vessels (arteries, veins and capillaries)

• Transports blood (oxygen and nutrients) throughout the body

Respiratory System

• Nose, larynx, pharynx, trachea, lungs, bronchi

• Diaphram - muscle that helps w/breathing

• Takes in oxygen and releases carbon dioxide

Nervous System

• Central Nervous System - brain and spinal cord

• Peripheral Nervous System - Nerve cells (neurons)

• Sends and receives messages (electrical impulses) to and from the brain.

Lymphatic/Immune System

• Lymphatic vessels, lymph nodes, thymus gland, tonsils, spleen

• Returns excess fluid in the body to the bloodstream.

• Helps fight against pathogens

Immune System• Collection of cells,

tissues and organs, including the lymphatic system

• White Blood Cells called lymphocytes (B cells and T cells) produced in bone marrow.

• Protects against infection by identifying and killing pathogens.

Digestive System

• Digestive Tract - Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus

• Liver, pancreas, and gall bladder helps with digestion

• Receives and breaks down food, absorbs nutrients, and excretes waste.

Endocrine System

• Regulates body functions• Glands and hormones

– Pituitary: Master gland– Hypothalamus: Brain– Thyroid: Metabolism– Parathyroids: Regulates

calcium in blood.– Adrenal: Produces

adrenaline– Pineal: Secretes

melatonin– Ovaries/Testes:

Reproduction– Pancreas: Produces

insulin to maintain blood glucose level.

Urinary System

• 2 Kidneys, 2 ureters, urinary bladder and urethra.

• Filters and cleans blood

• Produces, stores and eliminates urine.

Homeostasis

• Regulation of a living systems internal environment to maintain a stable constant normal condition.

• Required for living systems to be healthy and function normally.

• Controlled by “Feedback Mechanisms”– Receptors that either start or stop a reaction

using enzymes.

Feedback MechanismsExamples

• Increase in heart rate and respiration during exercise to get more oxygen to cells.

• Sweating to maintain a normal body temperature.

• Release of insulin by the pancreas to regulate blood glucose (sugar) levels.

• Plants regulating water loss and CO2 intake for photosynthesis and other life activities.