Chapter 25

Question 1

Define growth

Answer 1

For any multicelled species, it refers to an increase in the number, size, and volume of cells, measured in quantitative terms

Question 2

Define development

Answer 2

Series of stages in which specialized tissues, organs, and organ systems form in heritable patterns, measured in qualitative terms

Question 3

Plant cells must be bathed in a fluid. Why?

Answer 3

It delivers nutrients and carries away metabolic wastes.

Question 4

Define extracellular fluid

Answer 4

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

Question 5

List basic body functions

Answer 5

acquiring materials and distributing then to cells, getting rid of wastes, protecting cells and tissues, reproducing, and often nurturing offspring

Question 6

All multicelled species respond, structurally and functionally, to this common challenge

Answer 6

Quickly move gaseous molecules to and from individual cells

Question 7

Define diffusion

Answer 7

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

Question 8

How do plants and animals diffuse gas?

Answer 8

In directions that are most suitable for metabolism and cell survival

Question 9

What happens is a metabolic reactions?

Answer 9

reactants diffusing through the body or to/from the surface, when this takes too long, reactions slow or stop.

Question 10

Explain internal transport in large bodies

Answer 10

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)

Question 11

What kind of transport system do plants and animals have?

Answer 11

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)

Question 12

What do plants and animals continually gain and lose?

Answer 12

water and solutes

Question 13

What is active transport?

Answer 13

Protein pumps one specific solute from a region of low concentration to one of higher concentration

Question 14

What is a crucial similarity between plants and animals?

Answer 14

dependence on communication between cells

Question 15

Define habitat

Answer 15

a place where individuals of a species typically live

Question 16

Each cell and muticelled body is interconnected through their requirement/contributions to what?

Answer 16

gas exchange, nutrition, internal transport, stability in internal environment, and defense

Question 17

Define Interstitial fluid

Answer 17

an extracellular fluid that fills spaces between cells and tissues. cells and blood exchange solutes with it

Question 18

Besides interstitial fluid, what makes up extracellular fluid?

Answer 18

plasma, the fluid portion of blood.

Question 19

Define sensory receptors

Answer 19

cells or cell parts that detect stimuli, which are specific forms of energy

Question 20

Dine integrator

Answer 20

a central command post that receives and processes information about stimuli

Question 21

Define effectors

Answer 21

muscles, glands, or both receives signals from the integrator to carry out suitable responses to the stimulation [check diagram on page 416]

Question 22

Define feedback mechanisms

Answer 22

homeostatic controls that help maintain physical and chemical aspects of the body’s internal environment

Question 23

Give an example of a positive feedback mechanism

Answer 23

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

Question 24

Give an example of a negative feedback mechanism

Answer 24

receptors that monitor oxygen levels signal to the brain when the concentration of oxygen in the blood declines and calls for faster, deeper breathing