2.3 Living Processes of Multicellular Organisms Flashcards
Epithelium cell
Structural adaptation:
Thin cells; arranged closely
Function:
Provide protection
Aids in gaseous exchange
Helps in nutrients absorption, secretes mucus
Muscles cell
Structural adaptation:
Contains many fibres; aid in movement
Have many mitochondria; provide energy for muscle contraction
Function: Contracts to produce movement
Nerves cell
Structural adaptation:
Have long dendrites and axon
Axons covered with myelin sheath; faster transmission
Function: Transmits nerve impulse from one part to another part of the body
Red blood cell
Structural adaption:
Contains haemoglobin; transport oxygen
Has a biconcave disc shape; increases the ratio of surface area per volume
Function: Transports respiratory gases
White blood cell
Structural adaption:
Can change shape; easily squeeze through the tiny blood vessels
Function: Protects the body from pathogens
Sperm cell
Structural adaption:
Has a long tail; helps the sperm to move
Contains mitochondrion; provide energy for the sperm to swim
Contains enzymes; helps the sperm to penetrate the ovum
Function: Fertilises the ovum
Spongy palisade mesophyll cell
Structural adaptation:
Packed loosely; efficient gaseous exchange
Function: Facilitate gas permeation
Xylem
Structural adaptation:
Consists of porous long tubes; to transport substances efficiently
Strengthen by lignin; to prevent the xylem from collapse
Function: Transport water and mineral salts from the roots to a whole plant
Sieve tubes
Structural adaptation:
Matured sieve tubes have no nucleus; provide more space for transportation
Have sieve plates
No lignin
Function: Transport organic substances; sucrose, amino acids and hormones from the shoots to other parts of the plant
Root hair cell
Structural adaptation:
Have many mitochondria; provide energy to absorb more mineral salts through active transport
The root hairs increase the surface area; maximising the absorption
Function: Absorb water and dissolved mineral salts
Guard cell
Structural adaptation:
Have chloroplasts; produce glucose
Have a large vacuole; control the osmotic pressure of the cell; aid in controlling the opening and closing of the stoma
Function: Control the opening and closing of the stoma
Cell Organisation:
Epithelium
- Consists of one or more layers of cells
- Some epithelium tissues form glands (exocrine and endocrine glands)
- Epithelial tissues carry out functions associated with protection, secretion and absorption
Muscles
Musculoskeletal: involves involuntary movements; contracts and relaxes to move the bones
Smooth: contracts and relaxes that allows involuntary movements; peristalsis in intestines
Cardiac: found in the heart walls; contracts and relaxes that allows pumping the blood
Nerve
- Consists of neurons or nerve cells
- Transmit nerve impulses, control and coordinates the activities in the body
Connective
- Consists of several types of cells and fibres that are distributed across the body that has many functions
- Loose connective tissues
- Fibrous connective tissues
- Cartilage
- Bone
- Blood tissues
- Adipose tissues
- Places between the organs
Functions to anchor the epithelium tissues to other tissues and places the organs in one place - Consists of fibrous collagens that are arranged close to one another
Found in tendon and ligament - Strong and flexible
Supports the nose, ears and covers the end of the bones, which functions to absorb pressure and shock - Consists of cells in one matrix of mineral salts and fibrous collagen
Collagen matrix is hardened by the deposition of minerals such as calcium phosphate
Functions to protect the organs and provides support to the body - Consists of blood cells; red blood cells, white blood cells and platelets
Blood functions to protect, transport and regulate - Functions to store fats, protects the organs and insulates heat
Found in the skin dermis and at the surroundings of the organs
Meristematic tissue
A group of undifferentiated cells; active in cell division
Two types; apical and lateral meristems
Function:
Apical meristem: primary growth; vertical growth
Lateral meristem: secondary growth; horizontal growth
Parenchyma tissue
Thin-walled cells; loosely arranged with spaces between them
Function:
- Provides support and shapes
- Stores food
- Conducts photosynthesis
Collenchyma tissue
Elongated, polygonal cells with unevenly thickened cell walls
Function:
Provides support to:
- Herbaceous plants
- Young stems
- Leaf stalks
Petioles
Sclerenchyma tissue
The cells are rigid
Have cell walls; thickened by lignin
Function:
- Provide support and protection to the plant
Epidermis
The wall of epidermal cells is normally covered by cuticle
Function:
The cuticle on the epidermal tissue helps to:
- Prevent water loss
- Protects the plants from mechanical injury
- Prevent the invasion by disease-causing microorganisms
In roots:
- the epidermal cells have long projections called root hairs; increase the surface area for absorption of water and minerals
In leaves:
- the lower epidermis contains guard cells; controls the opening and closing of stomata
Xylem
Consists of xylem vessels; long tubes joined together end to end
Provide support to plants
Function:
Xylem carries water and minerals from the roots to the leaves
Xylem provides support and mechanical strength to the plant
Phloem
Phloem tissue consists of parenchyma cells, sieve tubes and companion cells
Sieve tubes obtain nutrients and energy from the companion cells
Function:
Transports carbohydrates, amino acids, hormones from the leaves to storage organs and to the growing parts of plants
