B2.3 Cell specialisation

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Describe a zygote

an unspecialised cell produced from fertilization

Outline the impacts of chemical gradients on gene expression within an early-stage embryo

the gradient signaling of chemicals called morphogens impacts cell differentiation in a concentration-dependent manner. different concentrations of morphogens affect gene expression.

Outline two properties of stem cells. 

1. self-renewal

2. differenciation

Define stem cell niche.

locationns within th etissues where stem cells reside and recieve chemical signals that influence the fate of the stem cells

Outline the location and function of two types of multipotent stem cells in an adult human body

• Bone Marrow

  • all blood cells orginate from the same type of adult multipotent stem cell called hematopoietic stem cell

• Hair Follicle

  • all hair cells originate from the same multipotent stem cell called follicle stem cells.

Define totipotent, multipotent and pluripotent.

• Totipotent can differentiate into an entire organism (first 4 cells morula, blastocyst)

• Pluripotent can differentiate into any body cell but not the placenta (inside a blastocyst and plant cells)

• Multipotent can still become related cell types (adult stem cells)

• Unipotent can only become one type of cell.

Explain why pluripotent stem cells are most prevalent in the early embryonic development of a multicellular organism.

ensures that organisms can produce all the nessesary cell types for developement.

Relate the relative cell size to the specialized function of sperm, egg, red blood cell, white blood cell, neuron and striated muscle fibers.