Grade 10 Life Sciences – Plant (and Intro Animal) Tissues

These flashcards cover the key concepts from the lecture: categories and features of plant tissues, specific cell types and their functions, anatomy of roots, stems, and leaves, water and food transport, secondary growth, basic physiological concepts (turgor, plasmolysis), and a brief introduction to the four main animal tissue types.

What are the two broad categories of plant tissue based on ability to divide?

Meristematic tissue (cells can divide) and permanent tissue (mature cells cannot divide).

Define a simple plant tissue.

A tissue composed of only one cell type.

Define a complex plant tissue.

A tissue composed of more than one cell type.

Name the three primary meristems produced by the shoot apical meristem.

Protoderm, ground-meristem, and procambium.

Which primary tissues arise from the three primary meristems?

Protoderm → epidermis; ground-meristem → cortex & pith; procambium → primary xylem & primary phloem (vascular bundles).

Where are meristematic tissues located in a plant?

At the tips of roots, stems, and in all buds (apical and axillary).

List three characteristic features of meristematic cells.

Thin primary cell walls, large nuclei with dense cytoplasm, and cells tightly packed with almost no air spaces.

State two key features of the epidermis in plants.

Usually a single outer cell layer with thickened outer walls, often covered by a waxy, waterproof cuticle.

What is the role of guard cells surrounding a stoma?

They open and close the pore to regulate gas exchange and water loss; they contain chloroplasts.

Give the primary function of stomata.

Allow controlled movement of gases (CO₂, O₂, water vapour) into and out of the plant.

Describe the structure and function of a root hair.

Thin, hair-like epidermal outgrowth at root tips that greatly increases surface area for water and mineral absorption.

Name the three types of ground tissue.

Parenchyma, collenchyma, and sclerenchyma.

State two characteristics and two functions of parenchyma cells.

Large thin walls, large vacuoles with air spaces; functions in food storage, photosynthesis (chlorenchyma), and gas exchange.

Describe collenchyma and give its main function.

Elongated cells with unevenly thickened cell walls at the corners; provides flexible strength and support to stems and leaf veins.

What distinguishes sclerenchyma cells and what do they do?

Extra-thick, lignified walls; dead at maturity leaving a lumen; provide protection, strength, and support (fibres & sclereids).

What is the primary function of xylem?

Transport water and dissolved mineral ions from roots to the rest of the plant and provide mechanical support.

What is the primary function of phloem?

Transport dissolved organic food (e.g., sucrose) from leaves to all parts of the plant.

How do the living states of xylem and phloem cells differ?

Most xylem conducting cells are dead and hollow; phloem sieve-tube elements are living but lack a nucleus.

Compare movement direction in xylem vs phloem.

Xylem transport is unidirectional (root → shoot); phloem transport is bidirectional (up & down the plant).

Which two cell types compose the bulk of xylem?

Tracheids and vessel elements.

Name the main cell types found in phloem tissue.

Sieve tubes, companion cells, phloem parenchyma, fibres, and sclereids.

State one structural feature of xylem vessels that aids water movement.

Elongated cells joined end-to-end with no cross walls, forming wide, lignified tubes.

What is a sieve plate and where is it found?

Perforated cross wall between two sieve-tube elements that allows flow of food; found in phloem.

What produces annual growth rings in woody dicot stems?

Yearly activity of the vascular cambium forming new layers of secondary xylem (wood) and phloem.

How is the age of a tree determined from its trunk?

By counting pairs of light (spring/summer) and dark (autumn/winter) growth rings, each pair equals one year.

What is the function of the endodermis in roots?

Regulates movement of water and solutes into the vascular cylinder (stele).

In a dicot root cross section, where are xylem and phloem located?

Xylem is central forming a star or cross; phloem occurs between the xylem arms.

Describe the arrangement of vascular bundles in a dicot stem.

Vascular bundles form a ring with xylem to the inside, phloem to the outside, and a cambium layer between them.

Differentiate palisade mesophyll from spongy mesophyll.

Palisade: elongated, tightly packed, many chloroplasts for photosynthesis; Spongy: rounded, loosely packed with air spaces for gas exchange.

What is the purpose of the cuticle on leaves and stems?

Provides waterproofing and reduces water loss while offering protection.

Define the bundle sheath in a leaf.

Layer of parenchyma/sclerenchyma cells surrounding a vascular bundle, offering support and regulating transport.

Outline the pathway of water from soil to atmosphere in a plant.

Root hairs → cortex → endodermis → xylem → upward through stem → leaf veins → mesophyll → evaporates into air spaces → exits via stomata (transpiration).

What is meant by a turgid plant cell?

A cell whose vacuole is full of water, pressing the cytoplasm against the cell wall, giving firmness.

Define plasmolysis.

Shrinking of a plant cell’s cytoplasm away from the cell wall when placed in a very strong solution causing water loss.

List the four major animal tissue types.

Epithelial, muscle, nervous, and connective tissues.

Give a general definition of epithelial tissue.

Layers of closely packed cells that cover body surfaces and line cavities, providing protection and selective permeability.

State one primary function of connective tissue.

Provides support, binding, and transport (e.g., bone, blood, cartilage, adipose).

Name the three kinds of muscle tissue.

Skeletal, cardiac, and smooth muscle.

What is the basic role of nervous tissue?

Transmit electrical impulses for communication, coordination, and control in the body.

What is the role of the vascular cambium in stems and roots?

A lateral meristem that divides to produce secondary xylem inward and secondary phloem outward, increasing girth.