Bio Quiz 3 Notes

Skeletal system

Provides structural support, attachment points for muscles, and resistance against muscle contractions.

Muscle contractions

Movements controlled by the nervous system that facilitate skeletal movement.

Exoskeleton

A rigid support system covering the outside of an animal, offering protection but limiting growth and size.

Endoskeleton

A rigid support structure located inside the body of an organism, allowing for growth and support of larger bodies.

Hydrostatic skeleton

A fluid-filled compartment providing structural support and flexibility through pressure.

Molting

The process where animals with exoskeletons shed their outer layer to allow for growth.

Skeletal muscle

Striated muscle attached to the skeleton responsible for voluntary movement.

Smooth muscle

Non-striated muscle found in the walls of internal organs, controlling involuntary contractions.

Cardiac muscle

Striated muscle forming the contractile walls of the heart, responsible for pumping blood.

Flexion

The bending of a limb around a joint, decreasing the angle between body parts.

Extension

The straightening of a limb, increasing the angle between body parts.

Muscular antagonism

The activity of two paired muscles; one muscle contracts while the other relaxes to facilitate movement.

Diffusion

The movement of molecules from an area of high concentration to low concentration, striving for equilibrium.

Osmosis

A special type of diffusion involving the movement of water across a selectively permeable membrane.

Hypotonic solution

A solution with a lower solute concentration compared to another.

Isotonic solution

A solution with the same solute concentration as another solution.

Hypertonic solution

A solution with a higher solute concentration compared to another.

Facilitated diffusion

Passive transport of molecules across a membrane via transport proteins, still moving down the concentration gradient.

Active transport

The movement of molecules against their concentration gradient, requiring energy (ATP) to occur.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs between air and blood.

Negative pressure breathing

A mechanism in mammals whereby air is pulled into the lungs by creating a pressure differential.

Countercurrent exchange

An efficient gas exchange method in fish where blood and water flow in opposite directions.

Hemoglobin

A red protein in red blood cells that binds oxygen for transport throughout the body.

Turgid cells

Guard cells that swell and open stomata when filled with water.

Plasmolysis

The process where plant cells lose water in a hypertonic solution, causing the protoplast to shrink away from the cell wall.

Transport proteins

Proteins embedded in the membrane that facilitate the movement of molecules across a cell membrane.

Motor somatic system

The part of the peripheral nervous system responsible for voluntary muscle movements.

Peristalsis

The involuntary contractions of smooth muscles that move food through the digestive tract.

Buoyancy

The ability of an object to float in water, significant for aquatic animals during respiration.

Mesophyll

The ground tissue in leaves composed mainly of parenchyma cells, facilitating photosynthesis and gas exchange.

Guard cells

Cells that flank each stoma, changing shape to regulate the opening and closing of the stomatal pore.