B2,3 Cell Specialization Flashcards
Fertilization
The fusion of a male and female gamete to produce a zygote.
Zygote
The single-celled product of human gamete fusion.
Embryo
The product of continuous the cell division of a zygote, a mass of cells.
What’s the role of mitosis in cell division?
Ensures that the embryo has all the genes in the genome, so it can specialize/develop in any way.
Differentiation
A process by which cells develop along different pathways and become specialized for specific functions in the development of an embryo.
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How do morphogens contribute to embryo cell differentiation?
- Concentrations of morphogens indicate to a cell its position in the embryo and which pathway it should follow.
- They determine which genes are transcribed to produce mRNA and which proteins are made in each cell.
Give an example of the presence of morphogens:
Gradients of morphogens between the anterior and posterior of early-stage embryos.
What are the properties of stem cells?
They are self-replicating cells who are undifferentiated, and therefore retain the capacity to differentiate along different pathways.
What gives stem cells power in regeneration/repair in adult bodies despite their small percentage?
They are present in many human tissues.
The stem cell niche
The precise location of stem cells within a tissue that must provide the microenvironment required for them to remain undifferentiated for long periods of time or to proliferate rapidly.
Bone marrow
Soft, spongy tissue in the middle of the femur, sternum, and pelvis of humans.
How is bone marrow an example of a stem cell niche?
They receive 15% of cardiac output that gives them a big supply of blood carrying oxygen and other amino acids, and therefore contain haematopoietic that produce red red and white platelets each day.
Hair follicles
Pores in the skin that hold hair.
How are hair follicles an example of a stem cell niche?
They have blood capillaries that supply the necessary nutrients that allow them to divide repeatedly to generate the many cells needed for hair growth.
Totipotent Stem cells
- Can differentiate into any cell type, and are found in early-stage animal embryos.
- Useful in regenerative medicine
Pluripotent Stem cells
Able to differentiate into many cell types, but not all.
Multipotent Stem cells
Able to differentiate into several cell types, make up stem cells in adult tissues.
Male gamete size
3 micrometers wide, 50 micrometers long, makes it easier to swim to egg cell
Red blood cell size
- 7 micrometers in diameter, 1-2 micrometers thick
- allows passage through narrow capillaries
- gives large surface area-to-volume ratio so entry and exit o2 is rapid