Which of the following best describes the characteristics of the animal kingdom?

Which of the following best describes the characteristics of the animal kingdom?

• A. Multicellular, Autotrophic, Reproduce Sexually, Have Cell Walls and Chloroplasts
• B. Multicellular, Heterotrophic, Reproduce Sexually, Lack Cell Walls and Chloroplasts, Can Move at Some Life Stage, and Respond to Environment Due to Specialized Tissues Like Nerve and Muscle
• C. Unicellular, Heterotrophic, Reproduce Sexually, Have Cell Walls
• D. Multicellular, Autotrophic, Reproduce Sexually, Lack Tissues

Answer: (B)

Animals are multicellular, heterotrophic organisms that typically move at some life stage and respond to their environment using specialized tissues. They lack rigid cell walls and chloroplasts, which is why they don’t perform photosynthesis like plants. Reproduction is usually sexual, with stages that involve gametes, and many animals show mobility even if some life stages are sessile. The presence of nervous and muscular tissues in most animals enables quick responses and coordinated movement. The other descriptions don’t fit the animal kingdom as well: autotrophic organisms with chloroplasts describe plants or algae; unicellular organisms with cell walls describe many bacteria, fungi, or some algae; and multicellular organisms that are autotrophic or lack tissues don’t match the common animal features.

Animals are multicellular, heterotrophic organisms that typically move at some life stage and respond to their environment using specialized tissues. They lack rigid cell walls and chloroplasts, which is why they don’t perform photosynthesis like plants. Reproduction is usually sexual, with stages that involve gametes, and many animals show mobility even if some life stages are sessile. The presence of nervous and muscular tissues in most animals enables quick responses and coordinated movement.

The other descriptions don’t fit the animal kingdom as well: autotrophic organisms with chloroplasts describe plants or algae; unicellular organisms with cell walls describe many bacteria, fungi, or some algae; and multicellular organisms that are autotrophic or lack tissues don’t match the common animal features.