Cell Types and Tissues Part II

Flashcards covering the characteristics, functions, and types of plant cells including parenchyma, collenchyma, and sclerenchyma based on the Intro to Botany lecture.

Where do mitosis and cell division specifically originate in the plant?

Root and shoot apical meristems.

What is the transitionary state of cells as they leave the immediate meristematic region?

Ground meristem.

What is the primary difference in cellular activity between ground meristem and the pith?

Ground meristem is actively performing mitosis, whereas the pith (made of parenchyma cells) is not actively doing mitosis.

Which plant cell type is described as the most common, versatile, and basic cell?

Parenchyma.

What are the characteristics of parenchyma cell walls?

They have a thin primary cell wall and no secondary cell wall.

Which cell type makes up the majority of leaves, petals, fruits, and seeds?

Parenchyma.

Are parenchyma cells alive or dead at maturity?

Parenchyma cells are alive at maturity.

Why are parenchyma cells critical for wound healing and vegetative regeneration?

Because they retain the ability to perform cell division (mitosis) even after they are mature.

What is the function of the pith in a stem, and which plant group possesses it?

The pith serves as a storage region for water and nutrients; it is a feature of dicots, while monocots do not have a distinct pith.

What is the specific name for parenchyma cells that contain chloroplasts and perform photosynthesis?

Chlorenchyma.

What are common alternative names for chlorenchyma based on their shape and arrangement?

Palisade parenchyma (long, close-packed) and spongy parenchyma (loosely packed).

What distinguishing feature makes collenchyma cells strong?

The primary cell walls have thickened corners due to increased deposits of cell wall materials.

What is the functional role of collenchyma in growing stems and leaves?

They provide structural support and strength while the plant part is still growing and elongating.

What is a common culinary example of collenchyma tissues?

The strings found in celery.

What substance is found in the thick secondary cell walls of sclerenchyma that makes them waterproof?

Lignin.

How do nutrients enter sclerenchyma cells despite their thick, waterproof walls?

Through the plasmodesmata.

Why is sclerenchyma unsuitable for plant parts that are actively elongating?

Sclerenchyma cells are very tough and do not expand with turgor pressure, meaning they would restrict growth.

What are the two types of sclerenchyma cells based on their shape?

Fibers (long cells used for conduction and support) and sclereids (short cells used for mechanical support).

In a tree trunk, what is the benefit of the elasticity provided by sclerenchyma fibers?

It allows the tree to sway in the wind without breaking or becoming permanently bent.

What are examples of hard structures formed by sclereids?

Walnut and coconut shells, and the pits or stones of cherries and peaches.