Tissues in Action

Lexical flashcards covering plant and animal tissues, their classifications, functions, and the musculoskeletal system based on the Grade 9 Science transcript.

Tissue

A group of cells, similar in structure, that work together to perform a specific function.

Division of labour

The formation of different types of tissues that increases the efficiency of the body and enables it to carry out complex life processes.

Meristematic tissue

A tissue consisting of actively dividing cells responsible for growth in plants.

Apical meristem

Growth zones located at the tips of roots and shoots that help plants grow in length.

Lateral meristem

Meristematic tissue arranged in a ring in the stem that divides to increase the girth or diameter of the plant.

Annual growth rings

Ring-like patterns on the cut surface of wood used by scientists to estimate the age of a tree and understand past climatic conditions.

Intercalary meristem

Meristematic tissue located at the base of internodes or just above the nodes that helps plants regenerate after cutting or grazing.

Node

The point on a plant stem where branches or leaves arise.

Internode

The part of the plant stem located between two nodes.

Differentiation

The process by which newly formed meristematic cells lose the ability to divide and undergo changes in structure and function to become permanent tissues.

Permanent tissues

Tissues composed of cells that have lost the ability to divide and are specialised to perform specific functions like support, transport, or storage.

Epidermis

The outermost layer of the plant body, consisting of a tightly packed, single layer of flat and rectangular cells.

Cuticle

A waxy layer of cutin covering the epidermis that reduces water loss and protects against mechanical injury and parasites.

Stomata

Pores in the epidermis of leaves that facilitate gaseous exchange and transpiration.

Transpiration

The evaporation of water vapors through stomata, which helps in water transportation and elimination of wastes.

Parenchyma

Simple permanent tissue made of living cells with thin walls that mainly stores food and performs photosynthesis in green parts.

Collenchyma

Simple permanent tissue consisting of living cells with unevenly thickened corners due to pectin, providing support and flexibility.

Sclerenchyma

Simple permanent tissue with dead cells and thick walls due to lignin deposition, making plant parts hard and strong.

Xylem

Complex permanent tissue that transports water and minerals from roots to other parts of the plant and provides strength.

Phloem

Complex permanent tissue made mostly of living cells that transports food from leaves to other parts of the plant.

Sieve tubes

Long, tubular phloem cells joined end to end by perforated walls that transport food.

Companion cells

Specialised parenchyma cells that regulate the cellular functions and monitor the loading/unloading of sugars in sieve tubes.

Epithelial tissue

Tissue that forms the outer covering of the body and lines internal organs, composed of closely packed cells with very little intercellular space.

Connective tissue

A type of tissue that connects and supports other tissues, such as blood and bone.

Matrix

The substance in connective tissue that can be fluid, soft, or rigid, determining the tissue's consistency.

Haemoglobin

An iron-rich protein in Red Blood Cells (RBCs) responsible for the red colour of blood.

Platelets

Blood components that help in blood clotting at the site of an injury.

Cartilage

A connective tissue with a soft, jelly-like matrix that provides flexibility and cushions the ends of bones for shock absorption.

Tendon

A strong, flexible band of connective tissue that connects muscle to bone.

Ligament

Connective tissue that connects bone to bone, provides stability, and prevents dislocation.

Voluntary movements

Body movements under conscious control, such as running or writing, carried out by skeletal muscles.

Muscle fibres

Bundles of long, cylindrical cells that are unbranched and multinucleate.

Involuntary movements

Body movements that occur automatically without conscious control, such as the beating of the heart or digestion.

Cardiac muscles

Branched, cylindrical muscle fibres found only in the heart that work tirelessly and rhythmically without fatigue.

Neurons

Specialised cells of the nervous tissue that receive, process, and transmit messages.

Axon

A long fibre in a neuron that carries messages away from the cell body to the axon terminals.

Musculoskeletal system

The system made up of bones, muscles, joints, cartilage, tendons, and ligaments that helps the body move and maintain posture.

Joint

A junction between two or more bones that allows movement.

Pivot joint

The type of joint connecting the skull to the backbone, allowing the head to move side to side.

Ball and socket joint

A joint where the rounded top of one bone fits into a hollow of another, allowing movements in many directions.

Totipotency

The ability of some mature plant cells to undifferentiate, divide, and redifferentiate into an entire organism.