Describe how Dolly the sheep was cloned. Q.Q. 3/28/19 Describe how Dolly the sheep was cloned.

Chapter 21- Genetic Basis of Development

Zygote- fertilized egg that will eventually grow and develop into many different types of cells by the following processes: Cell division- Splitting of cells Cell differentiation- Process where cells become specialized in structure and function Morphogenesis- Process in which an organism will get its final shape

ANIMALS VS. PLANTS Animals- Require movement of cells/ tissues in order to fully develop Plants- Morphogenesis and growth continue throughout entire life at the (apical) meristem. MERISTEM = MITOSIS!   Blastula- Early stage of development characterized by a hollow sphere of cells (single layer thick) Gastrula- Early stage of development characterized by two layers of cells

21.2 Genomic equivalence- All *SOMATIC cells within a single organism will contain the same genes (with some exceptions) Totipotent (cells)- Able to turn into any type of cell (TOTAL) Changes occur within an animal’s life that prevents the adult cells from being totipotent. These genetic changes are usually based on the packing of chromatin within the cells

21.2 Stem cells- Undifferentiated and can reproduce indefinitely Adult stem cells- Pluripotent- Can give rise to a couple different types of cells (IE- Blood cells- either red or white) *NOT TOTAL/ALL TYPES

21.2 Therapeutic cloning- Raising embryonic stem cells for medical treatment of individuals Reproductive cloning- IE- Dolly the sheep. Somatic vs. gametic; haploid vs. diploid?

21.2 Determination- A cell “committing” to what it is going to be (said to be a myoblast in the next example).

MyoD protein decides what tissue is going to be muscle cells when differentiated.

21.2 Cytoplasmic determinants- Maternal substances in the egg that influence the course of early development

Pattern and Spatial plan development Pattern formation- Spatial organization (why every organ is generally in the same place in all of us). Controlled by molecular cues called positional information. Morphogens- Establishes embryos axes (IE- Bicoid protein)

Bicoid protein microscope video Animation

Homeotic genes- Anatomical identification of the segments of a body (IE- If this gene was mutated in a fruit fly, legs could grow out of the head). In animals, homeotic genes are called Hox genes. Video Transcription regulators

Induction- To induce differentiation by signal proteins

Apoptosis- Programmed cell death by “suicide” proteins Apoptosis- Programmed cell death by “suicide” proteins. Needed for proper development

*MAIN POINT of this chapter! Genetic codes are very similar in many organisms, but when and what is expressed is what causes differences. Ultimate basis for different cells- Transcription regulation! *Which then…-> regulates what proteins get made / not made -> regulates protein expressed/not expressed -> outcome of looks! (phenotypes)

Hox genes and Evolution https://youtu.be/voQQ1dhCqZg