Flashcards in [Chapter 25] Plants and Animals - Common Challenges Part I Deck (24)
For any multicelled species, it refers to an increase in the number, size, and volume of cells, measured in quantitative terms
Series of stages in which specialized tissues, organs, and organ systems form in heritable patterns, measured in qualitative terms
Plant cells must be bathed in a fluid. Why?
It delivers nutrients and carries away metabolic wastes.
Define extracellular fluid
ECF is the body fluid not inside cells, it acts as an internal environment. changes in its composition and volume affect cell activities. the type and number of ions must be kept at concentrations compatible with metabolism. *the body requires a stable fluid environment for its cells*
List basic body functions
acquiring materials and distributing then to cells, getting rid of wastes, protecting cells and tissues, reproducing, and often nurturing offspring
All multicelled species respond, structurally and functionally, to this common challenge
Quickly move gaseous molecules to and from individual cells
When ions or molecules of a substance are concentrated in one place, they tend to move to a place where they are not as concentrated
How do plants and animals diffuse gas?
In directions that are most suitable for metabolism and cell survival
What happens is a metabolic reactions?
reactants diffusing through the body or to/from the surface, when this takes too long, reactions slow or stop.
Explain internal transport in large bodies
as cells and multicelled organisms grow, their volume increases in three dimensions while surface area only increases in two dimensions, thus surface area to volume ratio decreases and diffusion alone is not able to move materials through it fast enough. larger bodies have systems of rapid internal transport that service individual cells that are too far from the exchange point with the environment (ex: the mouth that takes in oxygen in humans)
What kind of transport system do plants and animals have?
most have vascular tissues, or system of tubes through which substances move to and from cells. transports diverse substances like water, nutrients, hormones, and infection/injury fighting substances (animals - white blood cells, plants - chemicals)
What do plants and animals continually gain and lose?
water and solutes
What is active transport?
Protein pumps one specific solute from a region of low concentration to one of higher concentration
What is a crucial similarity between plants and animals?
dependence on communication between cells
a place where individuals of a species typically live
Each cell and muticelled body is interconnected through their requirement/contributions to what?
gas exchange, nutrition, internal transport, stability in internal environment, and defense
Define Interstitial fluid
an extracellular fluid that fills spaces between cells and tissues. cells and blood exchange solutes with it
Besides interstitial fluid, what makes up extracellular fluid?
plasma, the fluid portion of blood.
Define sensory receptors
cells or cell parts that detect stimuli, which are specific forms of energy
a central command post that receives and processes information about stimuli
muscles, glands, or both receives signals from the integrator to carry out suitable responses to the stimulation [check diagram on page 416]
Define feedback mechanisms
homeostatic controls that help maintain physical and chemical aspects of the body's internal environment
Give an example of a positive feedback mechanism
During childbirth, a fetus puts pressure on the wall of the uterus and the pressure induces the production and secretion of oxytocin that make muscle cells in the wall contract to exert pressure on the fetus, which repeats until the fetus leaves the mother's body