Simple IB Biology Amirali Ghajari

In this sub-unit of IB biology, we are going to explain the shortest part of unit 1, we are going to understand the concepts of:


Cells can only be formed by division of pre-existing cells
The first cells must have arisen from non-living material
The origin of eukaryotic cells can be explained by the endosymbiotic theory

In today's podcast we are going to explore and understand the concepts of:


Particles move across membranes by simple diffusion, facilitated diffusion, osmosis and active transport
The fluidity of membranes allows materials to be taken into cells by endocytosis or released by exocytosis
Vesicles move materials within cells

In this sub-unit we are going to explore the concepts and understanding of:

Understandings:


Phospholipids form bilayers in water due to the amphipathic properties of phospholipid molecules
Membrane proteins are diverse in terms of structure, position in the membrane and function
Cholesterol is a component of animal cell membranes

In this second part of unit 1 of the IB biology, we will explore the concepts of:


Prokaryotes have a simple cell structure without compartmentalization
Eukaryotes have a compartmentalized cell structure
Electron microscopes have a much higher resolution than light microscopes

Welcome everyone in the first episode of this podcast we are going to understand the key concepts of the first part of IB biology which are:


According to the cell theory, living organisms are composed of cells
Organisms consisting of only one cell carry out all the functions of life in that cell
Surface area to volume ratio is important in the limitation of cell size
Multicellular organisms have properties that emerge from the interaction of their cellular components
Specialized tissues can develop by cell differentiation in multicellular organisms

In the last sub-unit of unit 6 we are going to explore the content of:


Insulin and glucagon are secreted by β and α cells of the pancreas respectively to control blood glucose concentration
Thyroxin is secreted by the thyroid gland to regulate the metabolic rate and help control body temperature
Leptin is secreted by cells in adipose tissue and act on the hypothalamus of the brain to inhibit appetite
Melatonin is secreted by the pineal gland to control circadian rhythms
A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone