If every cell in the body gets the same dna, how do the cells of an embryo make different structures and take on different roles? (select all that apply.) a. different transcription factors are active in different cells. b. different transcription factors are encoded in the dna. c. genes are spliced differently in different cells. d. translation is regulated so that different cells may make more of certain proteins. e. some cells lack ribosomes while others use them. f. cells delete a set of unused genes from their chromosomes.

Every cell in the human body shares a common starting point: a fertilized egg. As a result, all of our cells theoretically contain the same DNA — ignoring specific cell types, such as erythrocytes and gametes, and the cumulative effects of DNA changes through mutation and telomere shortening. Despite this, each cell is unique, with one cell type completely dissimilar to another, not to mention being totally different to the original fertilized egg. Why?

The reason is that each cell — whether a neuron, skin cell, or a photoreceptor cell — uses the genes that it has differently. All cells have the same set of genes (~20,000 in humans) but it is up to the individual cell whether each gene is turned on or off.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.