Stem cells can divide indefinitely and can produce different types of cells, as shown in the model here. A student wants to revise the model to accurately depict how stem cell division and differentiation allows for specialized cells to develop while maintaining the ability for the stem cell to give rise to new cells. What revision to the model best depicts stem cell division and differentiation? A) The model should show apoptosis of the white blood cells that are unnecessary to the immune system. B) The model should show the original stem cell dividing to become a differentiated cell and another stem cell. C) The model should show the process of meiosis before cell differentiation since specialized cells are haploid. D) The model should show the reversion of the white blood cell back into a stem cell so that future differentiation can occur.

The construction of phylogenetic trees is a mapping out the proposed divisions and common ancestors of all living species. traditionally, these trees have been built using morphological data, such as appearance and embryology. recently, it has been possible to construct these trees using molecular data. phylogenetic trees based on different types of information agree with each: that there is strong evidence of a real underlying common descent. this phylogenic tree is composed based on molecular data (rrna). what statements can we infer are true about the organisms throughout the tree? because the tree is rooted, all branches share a common ancestor. all organisms have some sort of cellular structure/organization. all eukaryotes evolved from bacteria. since the organisms contain rna, they share the same dna. if the organisms contain rna, the share the same four nitrogen bases.

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal responds by in order to its core temperature?

Approximately what portion of the foods that we eat have been genetically modified in some way? a. fewer than 10% b. about 50% c. nearly 100%