Examkin

Question

Difficulty: EasyMorphological and Physiological Adaptations to Environments

Mangrove plants growing in estuarine swamps face low oxygen availability in waterlogged soils. Which of the following morphological adaptations enables these plants to obtain atmospheric air for root respiration?

  1. Specialized breathing roots (pneumatophores) growing upward above the mudAnswer
  2. B
    Deeply penetrating taproots for reaching underground water reservoirs
  3. C
    Sunken stomata located exclusively on the upper leaf surfaces
  4. D
    Broad floating leaves with thick waxy cuticles on both sides

Answer

Specialized breathing roots (pneumatophores) growing upward above the mud
Pneumatophores are specialized erect roots produced by mangrove plants (halophytes). Because the muddy soil in estuarine environments is waterlogged and severely depleted of dissolved oxygen, these roots grow upward against gravity into the air. Tiny pores called lenticels on their surfaces allow atmospheric oxygen to diffuse into the root tissues for respiration.

Step-by-Step Solution

1
Identify the environmental challenge in the stem
Estuarine swamps have waterlogged, anaerobic (oxygen-poor) mud.
Roots require oxygen for cellular respiration to generate energy for nutrient absorption.
2
Match the organism group and environmental challenge to its specific structural adaptation
Halophytes (mangroves) develop negative geotropic roots called pneumatophores equipped with lenticels.
Pneumatophores extend above the water level into the atmosphere to absorb oxygen directly.

Key Concept

Morphological Adaptations of Halophytes to Anaerobic Soils
Rate this question

Topics

Morphological and Physiological Adaptations to Environments

More questions from this topic