Logic of a solution: *Organisms cluster around hydrothermal vents in the ocean floor. Hydrothermal vents are fissures in the ocean floor that leak hot, acidic water. Organisms cluster around fissures in the ocean floor that leak hot, acidic water.*
*(D)*
The original question: *Where do organisms cluster on the ocean floor?
Options:
- (A) neutralized water
- (B) where they used to live
- (C) hot alkaline water
- (D) fissures of hot, acidic water
- (E) sedimentary rocks
- (F) fissures blasting cold water
- (G) at or near the margins
- (H) an area swollen with pus*

Line 1: *Mating is generally preceded by courtship. Friendship usually precedes courtship, and courtship, marriage. Friendship often comes before mating.*
*(C)*
Line 2: *What often precedes mating?
Options:
- (A) A Greek letter
- (B) competition
- (C) friendship
- (D) birth of a child
- (E) death
- (F) Chemical energy
- (G) pregnancy
- (H) sweating*

Logic of a solution: *Mutations that lead to cancer usually occur in genes that control the cell cycle. Mitosis is part of the cell cycle. Mutations that lead to cancer usually occur in genes aiding in mitosis.*
*(G)*
The original question: *Mutations that lead to cancer usually effect genes that aid in what?
Options:
- (A) illness
- (B) health
- (C) disease
- (D) blood transfer
- (E) chemotherapy
- (F) respiraration
- (G) mitosis
- (H) recovery*

Line 1: *Cell division is more complex in eukaryotes than prokaryotes. Asexual cell division is called Mitosis. Mitosis is more complex in eukaryotes than prokaryotes.*
*(F)*
Line 2: *What is more complex in eukaryotes than in prokaryotes?
Options:
- (A) plants
- (B) cell immigration
- (C) cell establishment
- (D) pollen
- (E) explosions
- (F) mitosis
- (G) A computer
- (H) orchids*

Logic of a solution: *Echinoderms lack a centralized nervous system. Echinoderms include starfish, sea urchins, and sea cucumbers. Starfish, sea urchins and sea cucumbers lack a centralized nervous system.*
*(D)*
The original question: *Starfish, sea urchins and sea cucumbers lack a what?
Options:
- (A) characteristics
- (B) the body's largest organ
- (C) watery habitat
- (D) centralized nervous system
- (E) functioning arm
- (F) underwater life
- (G) biological diversity
- (H) epidermis and dermis*

Logic of a solution: *Aging is associated with the death of cells. Apoptosis means cell death. Apoptosis is a natural part of aging.*
*(B)*
The original question:
*What is a natural part of aging?
Options:
- (A) Smoking
- (B) apoptosis
- (C) regeneration
- (D) illness
- (E) stimulation
- (F) cracking
- (G) Weight
- (H) firm skin*