B2.3 (Cell Specialization) Flashcards
Define fertilization on terms of cells
multi-step process in which a sperm and egg fuse to form a single cell called a zygote.
Where does fertilization occur?
In sexually-reproducing organisms that produce haploid (single set unpaired chromosome) gametes
How does a zygote become an embryo?
Zygote divides by mitosis to form an embryo of genetically identical cells
Outline the process of mitosis
a eukaryotic cell nucleus splits in two nuclei, followed by the division of the parent cell into two daughter cells
Explain which stages of embryonic development embryonic stem cells are found and when they become differentiated
The cells in zygote and embryo are unspecialized stem cells called ”embryonic stem cells” However, as the cells of the embryo continue to divide, they begin to specialize in structure and function.
Why is cell specialization needed?
It allows cells to perform a function with increased efficiency.
- Cells can develop into specific shapes and sizes
- Cells can create proteins needed to carry out specific metabolic reactions
Why are eukaryotes eukaryotes
They have a nucleus.
Define cell differentiation
The development of specialized structures and functions in cells
Describe gene expression
The process by which the information encoded in a gene is used into the synthesis of a functional gene 🧬 product
Often in gene expression, a sequence of DNA is transcribed from RNA which is then translated to form a protein
Define morphogens
Gradients of signaling chemicals that impact gene expression and as a result, the differentiation of the cell.
(TURNS CERTAIN GENES ON AND OFF??)
Describe differentiation during embryonic development from blastocyst to fetus
a
How do the morphogens make the gradient
Create a concentration gradient: Morphogens are released from a specific source in the developing tissue and diffuse outwards. This creates a gradient, with the highest concentration closest to the source and gradually decreasing as you move further away.
- Trigger different developmental fates: Cells within the developing tissue interpret the concentration of the morphogen they sense. Different concentrations trigger specific genetic programs in the cells, instructing them to differentiate into different cell types.
Think of it like a volume knob: Imagine the morphogen concentration as a volume knob. Low settings (low concentration) activate genes for quiet music (one cell fate), while high settings (high concentration) activate genes for loud rock music (a different cell fate).
Why is the egg cell considered a differentiated cell
Because it is specialized; it contains only half of the genetic material (haploid)
How can the environment of a cell impact on gene expression? Have an example
1.) Environmental conditions can regulate gene expression.
e.g.: A protein called melanin is present in rabbits. It is regulated by a temperature-sensitive enzyme which would darken some parts of the rabbit
Describe tissues
A group of cells that specialize in the same way and perform the same function.
- only present in multicellular organisms
Outline the benefits of a cell specialization in a multicellular organism
- focus on fewer tasks at once to do the work more efficiently while saving energy
- they have specialized structures
Describe adult stem cells
Define stem cells [3]