Protozoa, Bryophytes, Gymnosperms, and Angiosperms: A Comparison

Protozoa

Features:

• Microscopic and eukaryotic unicellular organisms.
• Exhibit movement.
• Aquatic, living in aquatic or terrestrial environments.
• Some are free-living; others are parasites.
• Reproduction may be sexual or asexual.

Classification:

• Mastigophora (Flagellates): Possess flagella for locomotion.
• Rhizopods (Sarcodina): Move via pseudopods, extensions of the cytoplasm.
• Ciliophora (Ciliates): Move using cilia.
• Apicomplexa (Sporozoa): Have a complex life cycle; all are parasites.
• Suctoria: Have cilia in their juvenile phase and tentacles in adulthood.

Locomotion: Move by extending cytoplasm externally (pseudopods), into which the rest of the cytoplasm flows.

Nutrition: Engulf organic particles via pseudopods, forming a digestive vacuole. Enzymes digest the particles through phagocytosis.

Reproduction: Reproduce asexually by binary fission. The nucleus divides first, resulting in two identical daughter amoebas.

Bryophytes

Characteristics:

• Represent the simplest plant forms.
• Lack true roots, stems, and leaves.
• Depend on water for reproduction, as they lack vascular tissues for efficient nutrient transport.
• Reproduce both sexually (zygote formation) and asexually (spores).

Gymnosperms

Features:

• Woody stems with tracheids.
• Leaves are acicular (needle-shaped) in pines or scale-like in cypresses.
• Lack true flowers; they are unisexual.
• Ovules are not protected inside an ovary.
• Seeds are not enclosed within a fruit.
• Sexual reproduction via gametes.

Angiosperms

• Can be woody or herbaceous; possess tracheids.
• Leaves are laminate with venation.
• Have true flowers, which are the reproductive organs.
• Ovules are enclosed in an ovary.
• Seeds are enclosed within a fruit.

Comparative Table

Monocotyledons

• Possess a single cotyledon.
• Vascular bundles are scattered.
• Leaf veins are parallel.
• Unbranched stem.

Dicotyledons

• Possess two cotyledons.
• Vascular bundles arranged in a circle.
• Leaves with branched veins.
• Branched stem.

Tracheophytes

Features (Filicinae - Ferns):

• Have a well-developed vascular system (xylem and phloem).
• Possess true leaves, stems, and roots.
• Compound leaves called fronds, composed of pinnae.
• Brown spots (sori) appear on leaves; sori are clusters of sporangia containing spores.