Practice 2 

1. (B) The passage states that slime molds "were regarded as organisms of ambiguous [uncertain] taxonomic status."

2. (D) To "ingest" or "consume" bacteria means to eat it as food.

3. (C) The passage states that "Their uniqueness lies in an unusual life cycle, which alternates between a feeding stage in which the organism is essentially unicellular and a reproductive stage in which the organism adapts a multicellular structure."

4. (A) The passage states that "the organism initiates a new genetic program that permits the cells to eventually find a new, food-rich environment."

5. (D) An "entity" or "unit" is an assemblage of parts, or as in this case, members.

6. (A) There are two distinct kinds of cells. Other "cells" form prespore cells.

7. (C) The author does not mention legs. The organism moves like a slug and then changes to a fungi-like form on a stalk.

8. (D) When something bears fruit, it is at the stage where the next generation is produced. The author is referring to the organism as being ready to release its spores and reproduce.

9. (B) After the spores that form the head ("the head develops into spores") are scattered around the area ("are dispersed into the environment"), they develop ("form") into a new generation ("the next generation") of amoebae cells.

10. (A) Developmental biologists are interested in this transformation because "the change in degree of specialization" is similar "to an important process found in higher [more complex] organisms in which organs with highly specialized functions are formed from unspecialized stem cells."

11. (A) The passage states the DNA approach "has essentially backed up the results of the earlier dye studies."

12. (A) The first square. The word "Starvation" refers to "become starved" and explains when this occurs. It would follow that sentence.

13.  

Unspecialized Cells

l          (B) "Bacteria-consuming amoebae... " - The passage states that the organism is unicellular during the feeding stage.

l          (F) "Mass formed... " - The passage states that "This mass [the cells that have come together] sticks together through the secretion of adhesion molecules."

l          (G) "Migration oriented to... " - The passage states that "Once a favorable location has been found with a fresh source of bacteria to feed on, the migration stops."

l          (H) "Production of... " - The passage states that "a few of the amoebae start to produce periodic chemical pulses that are detected, amplified, and relayed to the surrounding members, which then move toward the pulse origin."

 

Specialized Cells 

l          (D) "Development of... " - The passage states that "the back cells climb up the stalk and form a spherical-shaped head, known as the sorocarp."

l          (E) "Dispersal... " - The passage states that "The head develops into spores, which are dispersed."

l          (I) "Transformation... " - The passage states that "The front cells turn into a stalk, and the back cells climb up the stalk and form a spherical-shaped head."