Line 1: *Cells are programmed to divide only a set number of times. Apoptosis is programed cell death. Division can only happen a certain number of times before apoptosis kicks in.*
*(F)*
Line 2: *What kicks in after a certain number of divisions?
Options:
- (A) Energy.
- (B) antibiotics
- (C) Energy
- (D) separation
- (E) nerves
- (F) apoptosis
- (G) soccer leagues
- (H) Plants growth*

Logic of a solution: *Producers are organisms that produce food for themselves and other organisms. Producers are the base of the food chain. The base of the food chain help provide food for other organisms.*
*(D)*
The original question: *What does the base of the food chain provide food for?
Options:
- (A) It helps them survive
- (B) sediments
- (C) Most plants
- (D) other organisms
- (E) our planet
- (F) energy systems
- (G) fruits
- (H) Animal survival*

Line 1: *Prokaryotes are single-celled organisms that lack a nucleus. Bacteria are said to be prokaryotes . Bacteria are single-celled organisms that lack a nucleus.*
*(G)*
Line 2: *What are single-celled organisms that lack a nucleus?
Options:
- (A) ferns
- (B) barnacles
- (C) Most plants
- (D) cacti
- (E) Leeuwenhoek
- (F) orchids
- (G) bacteria
- (H) PDAs*

Logic of a solution: *Plants are multicellular eukaryotes with cell walls made of cellulose. Basically, fiber is cellulose . Plants cell walls are made of fiber.*
*(A)*
The original question: *Plants cell walls are made of
Options:
- (A) fiber
- (B) keratin
- (C) alveoli
- (D) cations
- (E) matter
- (F) CO 2
- (G) porous
- (H) Cane.*

Line 1: *Feathers help birds fly and provide insulation. Class Aves is for the birds, literally. Feathers help animals in the class Aves fly and give them insulation.*
*(E)*
Line 2: *Feathers help what kind of animals fly and provide insulation?
Options:
- (A) preventing heat transfer
- (B) dragons
- (C) passenger pigeons
- (D) butterflies
- (E) animals in the class Aves
- (F) airplanes
- (G) it protects them
- (H) retaining heat*

Line 1: *Thyroid hormones increase the rate of metabolism in cells throughout the body. Metabolism is the process of converting food to energy. Thyroid hormones increase the rate of converting food to energy.*
*(G)*
Line 2:
*Thyroid hormones increase the rate of
Options:
- (A) by making heat
- (B) the rest of the body
- (C) female sex cells
- (D) Helps them grow
- (E) hydration of their cells
- (F) heat produced
- (G) converting food to energy
- (H) aerobic capacity*