13. Which of the following is a benefit of social behavior?
A) Division of labor as workers and soldiers
B) Leads to stable groups
C) Provides protection against attack
D) All of the above

14. Which of the following animals is odd?
A) Porifera
B) Cnidaria
C) Annelida
D) Reptiles

15. A type of frog genus found in the Bale Mountains and Shoa Forest, Ethiopia, is:
A) Ptychadena herena
B) Ptychadena goulengeri
C) Leptopelis ragazzi
D) A & C
E) B & C

16. __________ is the process of maintaining a constant internal body temperature.
A) Thermoregulation
B) Osmoregulation
C) Poikilotherm
D) Homeotherm

17. Which of the following is false?
A) All enzymes are proteins.
B) Proteins have different structures.
C) Enzymes are markers of various diseases.
D) The higher the activation energy, the lower the reaction rate.

18. A type of enzyme used to unwind DNA is:
A) Lipase
B) Acetylcholinesterase
C) Helicase
D) Trypsin

19. Which of the following is a physical property of enzymes?
A) Denaturation
B) Solubility
C) Colloidal nature
D) All of the above

20. What is the optimum temperature for enzyme activity in the human body?
A) 37°C
B) 25-30°C
C) 35-75°C
D) 5-30°C

21. Which of the following behavioral patterns of animals responds to periodic changes in the environment?
A) Reproductive behavior
B) Social behavior
C) Behavioral cycles
D) Competition

22. Which of the following is true?
A) Frogs do not produce amniotic eggs.
B) Crocodiles deposit their eggs in mound vegetation.
C) Birds have camouflaged eggs.
D) Rats are representative of mammalian sexual reproduction.
E) All of the above

23. The major parts of a bird's egg are:
A) Yolk
B) Chalaza
C) Albumen
D) All of the above

24. Insects are considered beneficial because they:
A) Are effective pollinators
B) Serve as biological control agents
C) Are sources of useful products and potential protein
D) All of the above

25. The site where an enzyme binds its substrate is:
A) Active site
B) Substrate
C) Peptide bond
D) Product

26. In Pavlov's classical conditioning experiments on dogs, which of the following is an unconditioned response?
A) The sound of a bell before presenting food
B) The sight of food from far away
C) The salivation of a dog at the sight of food
D) All of the above

27. Which of the following is the phenomenon where a female gamete develops into a new organism without fertilization?
A) Monogamous
B) Polygamous
C) Parthenogenesis
D) All of the above

28. A group of animals that possess a well-defined internal skeleton system is:
A) Vertebrates
B) Invertebrates
C) Insects
D) A & B