Answer the following question given this paragraph: Q: Sediments in oligotrophic lakes contain large amounts of what? Choices: - algae - fertilizer - igneous rocks - decomposable organic matter A:
decomposable organic matter
Answer the following question given this paragraph: A neutron is a particle in the nucleus of an atom that has no electric charge. Atoms of an element often have the same number of neutrons as protons. For example, most carbon atoms have six neutrons as well as six protons. This is also shown in Figure below . Q: Carbon atoms have six neutrons as well as how many protons? Choices: - ten - two - four - six A:
six
Q: Answer the following question given this paragraph: Usually mutations in multiple genes are necessary to develop cancer. Q: What is usually necessary to develop cancer? Choices: - crucial genes mutations - massive genes mutations - novel genes mutations - multiple genes mutations A:
A: multiple genes mutations
Question: Answer the following question given this paragraph: Stem Cells A stem cell is an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into specialized cells. Stem cells are divided into several categories according to their potential to differentiate. The first embryonic cells that arise from the division of the zygote are the ultimate stem cells; these stems cells are described as totipotent because they have the potential to differentiate into any of the cells needed to enable an organism to grow and develop. The embryonic cells that develop from totipotent stem cells and are precursors to the fundamental tissue layers of the embryo are classified as pluripotent. A pluripotent stem cell is one that has the potential to differentiate into any type of human tissue but cannot support the full development of an organism. These cells then become slightly more specialized, and are referred to as multipotent cells. A multipotent stem cell has the potential to differentiate into different types of cells within a given cell lineage or small number of lineages, such as a red blood cell or white blood cell. Finally, multipotent cells can become further specialized oligopotent cells. An oligopotent stem cell is limited to becoming one of a few different cell types. In contrast, a unipotent cell is fully specialized and can only reproduce to generate more of its own specific cell type. Stem cells are unique in that they can also continually divide and regenerate new stem cells instead of further specializing. There are different stem cells present at different stages of a human's life. They include the embryonic stem cells of the embryo, fetal stem cells of the fetus, and adult stem cells in the adult. One type of adult stem cell is the epithelial stem cell, which gives rise to the keratinocytes in the multiple layers of epithelial cells in the epidermis of skin. Adult bone marrow has three distinct types of stem cells: hematopoietic stem cells, which give rise to red blood cells, white blood cells, and platelets... Q: A stem cell is an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into these? Choices: - clones - infectious cells - germ cells - specialized cells A:
Answer: specialized cells
*Question*
Answer the following question given this paragraph: Figure 7.3 In this illustration of the effects of crossing over, the blue chromosome came from the individual's father and the red chromosome came from the individual's mother. Crossover occurs between non-sister chromatids of homologous chromosomes. The result is an exchange of genetic material between homologous chromosomes. The chromosomes that have a mixture of maternal and paternal sequence are called recombinant and the chromosomes that are completely paternal or maternal are called non-recombinant. Q: The chromosomes that have a mixture of maternal and paternal sequence are called what? Choices: - antibodies - gene - DNA - recombinant A:
**Answer**
recombinant
Q: Answer the following question given this paragraph: The electrons in the outer energy level of an atom are called valence electrons . It is valence electrons that are potentially involved in chemical reactions. The number of valence electrons determines an element's reactivity, or how likely the element is to react with other elements. The number of valence electrons also determines whether the element can conduct electric current. That's because electric current is the flow of electrons. Table below shows how these properties vary in elements from each class. Q: What are electrons in the outer energy level of an atom called? Choices: - shell electrons - outer electrons - positive electrons - valence electrons A:
A: valence electrons