Cell structure & specialization

What are the four main aspects of the cell theory?

1. All living organisms are composed of cells 2) Cells are the smallest unit of life 3) All cells come from pre-existing cells 4) All cells contain hereditary information (DNA) which is passed on during cell division.

What is the difference between totipotent and pluripotent stem cells?

Totipotent stem cells can become any cell type in an organism, while pluripotent stem cells can develop into any adult cell type but not a complete organism.

How do stem cells contribute to tissue regeneration?

Stem cells can divide endlessly and differentiate into specialized cells, providing a renewable source for repairing and replacing damaged tissues.

What is differentiation in cellular biology?

Differentiation is the process through which a less specialized cell becomes a more specialized cell type.

What are the functions of mitochondria in eukaryotic cells?

Mitochondria are responsible for producing ATP, the main energy currency of the cell, through aerobic respiration.

What are the components common to all cells?

All cells have a plasma membrane, cytoplasm, genetic material (DNA), and ribosomes.

What is the significance of compartmentalization in eukaryotic cells?

Compartmentalization allows for specific cellular functions to occur in designated areas, increasing the efficiency of metabolic processes.

What is metabolism?

Metabolism refers to all the chemical reactions that occur within an organism to maintain life, including anabolic and catabolic processes.

How does size influence biological systems?

Smaller cells have a larger surface area to volume ratio which enhances nutrient absorption and waste removal, while larger cells may be more specialized and capable of complex functions.

What is the function of chloroplasts in plant cells?

Chloroplasts are the sites of photosynthesis, converting light energy into chemical energy stored in glucose.

Define 'homeostasis'.

Homeostasis is the maintenance of a stable internal environment within an organism despite changes in external conditions.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells lack a membrane-bound nucleus and organelles, whereas eukaryotic cells have these structures.

What is the role of ribosomes in cells?

Ribosomes are responsible for protein synthesis by translating mRNA into polypeptide chains.

What is the significance of the stem cell niche?

The stem cell niche provides a specialized microenvironment that regulates the function and fate of stem cells.

What are the functions of the Golgi apparatus in eukaryotic cells?

The Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

How do red blood cells challenge the traditional cell theory?

Red blood cells lack a nucleus, which contradicts the idea that all cells must have a nucleus.

What is a unicellular organism?

A unicellular organism is a living entity composed of a single cell that performs all necessary life processes.

Outline the eight functions of life.

1. Metabolism 2) Response to stimuli 3) Homeostasis 4) Growth 5) Movement 6) Reproduction 7) Excretion 8) Nutrition.