Chapter 39: Animal Form and Function

Phenotypic change

________ in an individual in response to environmental fluctuations is referred to as acclimatization.

Homeostasis

________ (literally,"alike- standing) "is defined as stability in the chemical and physical conditions within an organisms cells, tissues, and organs.

negative feedback

When ________ occurs, effectors return internal conditions to set- point values.

Skeletal muscle

________ is responsible for most body movements.

male

The ________ deposits the spermatophore on the females genital opening.

Neurons

________ transmit electrical signals, which are produced by changes in the permeability of the cell s plasma membrane to ions.

Homeotherms

________ " (alike- heat) "keep their body temperature constant, while in poikilotherms ("varied- heat), "body temperatures rise or fall depending on environmental conditions.

arrangement of proteins

It has long cells with a striated, or striped, appearance produced by an overlapping ________.

Nervous tissue

________ consists of nerve cells, which are also called neurons, and several types of supporting cells.

Cardiac muscle

________ makes up the walls of the heart and is responsible for pumping blood throughout the body.

tissue

A(n) ________ is a group of cells that function as a unit.

Metabolism

________ is 1e sum of all chemical reactions that occur within an organism.

digestive tract

Contraction and relaxation of smooth muscle help move food through the ________ and regulate blood pressure.

organ system

A(n) ________ consists of groups of tissues and organs that work toge er to perform one or more functions.

digestive enzymes

An organ is a structure that serves a specialized function and consists of two or more tissues; a gland is an organ at secretes specific molecules or solutions such as hormones or ________.

constant internal conditions

Many organisms are able to regulate their internal conditions to actively maintain relatively ________ even when the environment fluctuates.

skeletal muscle

The ________ attaches to bones and exerts a force on them when it contracts.

adaptations

heritable traits that make individuals more likely to survive and reproduce in a certain environment than individuals that lack those traits

spermatophore

a packet of sperm surrounded by a large, gelatinous mass

Muscle tissue

a key innovation in the evolution of animals-like nervous tissue, it appears in no other lineage on the tree of life