Topic 2.1. Cellular Differentiation

State the definition of cellular differentiation

The process by which an unspecialised cell changes into a specialised cell.

Explain the purpose of cellular differentiation

It allows multicellular organisms to perform specific functions efficiently through a division of labour as single cell types cannot effectively execute complex distinct tasks simultaneously.

Provide examples of tasks that single cell types cannot effectively execute

Pumping blood and transmitting nerve signals.

Describe the development of a multicellular organism

Every multicellular organism begins as a zygote that undergoes repeated mitosis, dividing into a cluster of identical pluripotent stem cells.

As this cluster grows, individual stem cells receive chemical signals that trigger specific genes to turn on and off. This causes cells to differentiate into specialised cells with specific structures and functions.

These differentiated cells then group together with other similar differentiated cells into tissues. Similar tissues then combine to construct organs that group and form organ systems. Eventually, this forms the complete multicellular organism.

State the hierarchy of biology from bottom to top

Cells → tissues → organs → organ systems → organism

Name the four main types of tissue

Epithelial, muscle, nerve, and connective.

State the function of the epithelial tissues

Its responsible for protecting tissues from physical damage, pathogens, bacteria, and chemicals by lining internal cavities, organs and blood vessels and forming the outer layer of skin.

State the function of the muscle tissues

Its responsible for producing movement and pumping blood by generating force through contraction and relaxation.

State the function of the nerve tissues

Its responsible for detecting stimuli, processing information, and electric impulse transmission.

State the function of the connective tissues

Its responsible for providing shape and transporting materials by connecting bones, tendons, fat and cartilage.

State the chemical requation for respiration

C6H12O6 + 6O2 → 6CO2 + 6H20 + ATP

State the definition of breathing

The process of moving air into and out of the lungs to facilitate gas exchange between the external environment and the body’s internal systems.

State the function of breathing

It’s responsible for supplying oxygen to the lungs and removing carbon dioxide. 

Explain the difference between respiration and breathing

Breathing is the physical act of moving air in and out of the lungs.

Respiration is the chemical process inside cells that breaks down food to release energy.

What organ conducts breathing?

Lungs

Describe the relationship between respiration and breathing

Respiration utilise the oxygen supplied through breathing to conduct its chemical processes/

State the definition of the term, multicellular organism

A living thing that is composed of more than one cell.

Provide examples of multicellular organisms

Plants and animals.

State the definition of the term, zygote.

The single diploid cell formed by the fusion of two haploid gametes during fertilisation.

State the definition of pluripotent

The ability of a stem cell to differentiate into almost any specialised cell type in the organism.

State the definition of the term, mitosis.

A type of cell division where one cell divides into two genetically identical daughter cells for growth and repair.

State the definition of the term, meiosis.

A type of cell division that produces four genetically unique haploid gametes.

What cells are not somatic cells?

Gametes

State the definition of the term, gamete.

A haploid male or female sex cell

State the definition of the term, stem cell.

An unspecialised cell capable of self-renewal and cellular differentiation.

State the definition of the term, somatic cell.

Any biological cell forming the body of a multicellular organism.

State the function of DNA

To contain genetic instructions that direct the cell to assemble amino acids into specific proteins.