Question

multiple choice
directions: the choice that best completes the statement or answers the question.

1. all the members of the kingdom animalia

a. are heterotrophs.
b. are multicellular.
c. have cells without cell walls.
d. all of the above

1. refer to the illustration above. organism 2

a. has no symmetry.
b. is bilaterally symmetrical.
c. exhibits radial symmetry.
d. has reverse symmetry.

1. refer to the illustration above. organism 1

a. has no symmetry.
b. is bilaterally symmetrical.
c. exhibits radial symmetry.
d. has reverse symmetry.

1. which of the following displays radial symmetry?

a. a flatworm
b. a chordate
c. an annelid
d. a cnidarian

1. in sponges, digestion occurs

a. in a gut.
b. in individual cells.
c. in a central cavity with a single opening.
d. outside of the animals body.

1. during which of the following stages of animal development are the germ layers formed?

a. fertilization
b. gastrulation
c. cleavage
d. organ formation

Explanation:

1. For question 1: All animals are heterotrophs (rely on other organisms for food), multicellular, and their cells lack cell walls (a feature that distinguishes animal cells from plant/fungal cells).
2. For question 2: Organism 2 (a cnidarian-like organism) can be divided into equal parts around a central axis, which is radial symmetry.
3. For question 3: Organism 1 (a butterfly) can be divided into two mirror-image halves along one plane, which is bilateral symmetry.
4. For question 4: Cnidarians (e.g., jellyfish, sea anemones) are defined by having radial symmetry; flatworms, chordates, and annelids have bilateral symmetry.
5. For question 5: Sponges are simple organisms with no true gut; they perform intracellular digestion, meaning digestion happens inside individual cells.
6. For question 6: Gastrulation is the developmental stage where the embryo folds in on itself, forming the three primary germ layers (ectoderm, mesoderm, endoderm).

Answer:

1. d. All of the above
2. c. exhibits radial symmetry.
3. b. is bilaterally symmetrical.
4. d. a cnidarian
5. b. in Individual cells.
6. b. Gastrulation