Regulating Internal Environment and REVIEW FOR UNIT 8

Organs- organized groups of tissue

•      Systems- Integumentary (skin), Muscular, Skeletal, Nervous, Endocrine, Circulatory, Respiratory, Lymphatic, Digestive, Urinary, Reproductive

Regulating the Internal Environment

• the interstitial fluid refers to the internal environment of an animal
• homeostasis is the state of internal balance (regulation); 3 components: receptor, control, and effector, receptor detects change, control center processes info and directs effector to make a proper response
• negative feedback - a change in the variable being monitored triggers a change in the control center that prevents further change in the variable or brings the variable back within wanted perimeters
• metabolic rate is defined as the amount of energy it uses in a unit of time

Regulating and Conforming

• conformer - allows internal condition to conform to external changes in the variable (like an ectotherm)
• regulator - uses internal control mechanisms to regulate internal change in the face of external fluxuation (like an endotherm)
• endothermic - warmed by heat generated by metabolism (warm blooded)
• ectothermic - doesn't produce enough body heat by metabolism to influence their body temperature (cold blooded)

UNIT 8 REVIEW QUESTIONS: EVOLUTION

1. Heterozygote advantage should be most closely linked to which of the following?

a) stabilizing selection

b) directional selection

c) disruptive selection

d) random selection

e) sexual selection

2. Each of the following has a better chance of influencing gene frequencies in small populations than in large populations, but which one most consistently requires a small population as a precondition for its occurrence?

a) genetic drift

b) gene flow

c) non-random mating

d) mutation

e) natural selection

3. "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's mistake?

a) disuse of an organ may lead to its eventual disappearance

b) only favorable adaptations have survival value

c) characteristics acquired during an organism's life are generally not passed on through genes

d) overproduction of offspring leads to a struggle for survival

e) spontaneous mutations can result in the appearance of new traits

4. Charles Darwin was the first person to propose?

a) that evolution occurs

b) a way to use artificial selection as a means of domesticating plants and animals

c) that the Earth is older than a few thousand years

d) a mechanism for how evolution occurs

e) a mechanism for evolution that was supported by evidence

5. Which of the following must exist in a population before natural selection can act upon that population?

a) sexual reproduction

b) genetic variation among individuals

c) variation among individuals caused by environmental factors

d) B and C only

e) A, B, and C

answers: 1. a; 2. a; 3. c; 4. e; 5. b