Why can't most STIs be transmitted through casual contact with people or contaminated objects? edg 2020

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.