Problem:OPTIONS:
- 50.3 blood cells
- s.a blood cells
- Deep Blood Cells
- red blood cells

Answer the following question given this paragraph: Primary Centers of the Immune System Although the immune system is characterized by circulating cells throughout the body, the regulation, maturation, and intercommunication of immune factors occur at specific sites. The blood circulates immune cells, proteins, and other factors through the body. Approximately 0.1 percent of all cells in the blood are leukocytes, which encompass monocytes (the precursor of macrophages) and lymphocytes. The majority of cells in the blood are erythrocytes (red blood cells). Lymph is a watery fluid that bathes tissues and organs with protective white blood cells and does not contain erythrocytes. Cells of the immune system can travel between the distinct lymphatic and blood circulatory systems, which are separated by interstitial space, by a process called extravasation (passing through to surrounding tissue). The cells of the immune system originate from hematopoietic stem cells in the bone marrow. Cytokines stimulate these stem cells to differentiate into immune cells. B cell maturation occurs in the bone marrow, whereas naive T cells transit from the bone marrow to the thymus for maturation. In the thymus, immature T cells that express TCRs complementary to self-antigens are destroyed. This process helps prevent autoimmune responses. On maturation, T and B lymphocytes circulate to various destinations. Lymph nodes scattered throughout the body, as illustrated in Figure 42.20, house large populations of T and B cells, dendritic cells, and macrophages. Lymph gathers antigens as it drains from tissues. These antigens then are filtered through lymph nodes before the lymph is returned to circulation. APCs in the lymph nodes capture and process antigens and inform nearby lymphocytes about potential pathogens. Q: The majority of cells in blood are erythrocytes or? A:
****
A: red blood cells

Answer the following question given this paragraph: Bones look tough, shiny, and white because they are covered by a layer called the periosteum . Many bones also contain a soft connective tissue called bone marrow in the pores of the spongy bone. Bone marrow is where blood cells are made. Q: What layer covers the bones that make them look tough, shiny, and white? A:
OPTIONS:
- epithelium
- cuticle
- epidermis
- periosteum
periosteum

Answer the following question given this paragraph: E XA MP L E 1 1. The most common carbon atoms have six protons and six neutrons in their nuclei. What are the atomic number and the mass number of these carbon atoms?. Q: The most common carbon atoms have six protons and six neutrons in their what? A:
OPTIONS:
- ribosomes
- neuron
- membrane
- nuclei

Answer: nuclei

Question: Answer the following question given this paragraph: The atomic number is the number of protons in an atom. This number is unique for atoms of each kind of element. For example, the atomic number of all helium atoms is 2. Q: The number of protons in an atom is called what? A:
OPTIONS:
- mass number
- metallic number
- isotope
- atomic number
Answer: atomic number

input with options: Answer the following question given this paragraph: Wallace and Darwin both observed similar patterns in other organisms and independently conceived a mechanism to explain how and why such changes could take place. Darwin called this mechanism natural selection. Natural selection, Darwin argued, was an inevitable outcome of three principles that operated in nature. First, the characteristics of organisms are inherited, or passed from parent to offspring. Second, more offspring are produced than are able to survive; in other words, resources for survival and reproduction are limited. The capacity for reproduction in all organisms outstrips the availability of resources to support their numbers. Thus, there is a competition for those resources in each generation. Both Darwin and Wallace's understanding of this principle came from reading an essay by the economist Thomas Malthus, who discussed this principle in relation to human populations. Third, offspring vary among each other in regard to their characteristics and those variations are inherited. Out of these three principles, Darwin and Wallace reasoned that offspring with inherited characteristics that allow them to best compete for limited resources will survive and have more offspring than those individuals with variations that are less able to compete. Because characteristics are inherited, these traits will be better represented in the next generation. This will lead to change in populations over generations in a process that Darwin called "descent with modification. " Papers by Darwin and Wallace (Figure 11.3) presenting the idea of natural selection were read together in 1858 before the Linnaean Society in London. The following year Darwin's book, On the Origin of Species, was published, which outlined in considerable detail his arguments for evolution by natural selection. Q: What did darwin call the evolutionary concept of change in populations over generations? A:
OPTIONS:
- formation with modifications
- reproduction with modifications
- metabolism with modifications
- descent with modifications
output: descent with modifications

Problem: OPTIONS:
- by texture
- by shape
- by smell
- by color
Q: Answer the following question given this paragraph: There are two common ways to measure pH. When only an approximate pH value is needed, an inexpensive test involves the use of acid-base indicators , which change color based on the relative acidity of the solution. One type of common indicator is litmus paper. For example, if a piece of litmus paper is dipped into an acidic solution (pH below ~4.5), it will turn red, and dipping it into a basic solution (pH above ~8.5) will turn it blue. Solutions of intermediate pH will result in various shades of purple. Because different indicators change color at different pH values, the use of multiple indicators can generally narrow down the possible pH of a solution to a range of about 0.5-1 pH units. Figure below shows the colors exhibited by various indicators at different pH values. Q: How does litmus paper indicate the ph value of a solution? A:
Answer:
by color