Metaphase is when the spindles attach to the chromosomes and they move to the center.
In biology, evolution is the change in the inherited traits of a population from generation to generation.
Common traits that have evolved in creatures are multicellular, heterotrophic, obtaining their energy by consuming energy-releasing food substances, reproduction and changes in cell structures.
<h2>Mitotic Cell Cycle</h2>
Explanation:
a. Cytochalasin: an inhibitor of actin microfilament
- Cytokinesis is the process by which cytoplasm is divided into two cells hence generation of two daughter cells
- In animal cells the division of cytoplasm starts with the assembly of contractile ring
- Contractile band consists of actin and myosin and catalyze cleavage furrow formation
- Cytochalasin is a drug that blocks the polymerization of actin filament
- When cytochalasin is added dividing cell fails to undergo in cytokinesis due to defective assembly of contractile band
b. Colchicine: an inhibitor of microtubule formation
- Colchicine tightly binds with free tubulin dimer and prevents its polymerization
- In this case mitotic spindle apparatus do not assemble and cells unable to do partitioning of chromosomes into two groups
- Thus cell division is arrested
c. Aphidicolin: an inhibitor of DNA Polymerase activity
- Aphidicolin is used to induce cell cycle arrest via specific inhibition of DNA Polymerase α
- It blocks the cell cycle at early synthesis(S) phase
d. Emetine: an inhibitor of ribosome activity
- It blocks the protein synthesis in eukaryotic cells by binding to small subunit(40 S) of ribosomes
- It interferes with the synthesis and activities of DNA and RNA
<span>The left and right Parietal bones.
There are eight major bones that form the cranium. They are:
Ethmoid: Forms the lower eye orbits and ceiling of the nasal cavity.
Frontal: Forms the front of the cranium which includes the forehead, brow ridges, and nasal cavity.
Occipital: Forms the lower rear of the cranium.
Parietal (left and right): Form the superior and lateral portion of the cranium.
Sphenoid: Forms some of the eye orbits and the floor of the cranium.
Temporal (left and right): Forms the sides of the cranium and the external ear.</span>
TOPOISOMERASE
There are various function of DNA toposisomerase such as:
1.accessing DNA- this happens during transcription and replication, DNA must be unwound for this to happen, Topoisomerase I make a single break to create an access.
2. Removing DNA super coils- Topoisomerase prevents DNA to be supercoiled, this happens during transcription of DNA to RNA
3. Strand breakage- It can introduce single strand breaks that are required for DNA to be exchanged to adjacent chromosomes.
