Answer the following question given this paragraph: Hemoglobin of the Fetus The fetus has its own circulation with its own erythrocytes; however, it is dependent on the mother for oxygen. Blood is supplied to the fetus by way of the umbilical cord, which is connected to the placenta and separated from maternal blood by the chorion. The mechanism of gas exchange at the chorion is similar to gas exchange at the respiratory membrane. However, the partial pressure of oxygen is lower in the maternal blood in the placenta, at about 35 to 50 mm Hg, than it is in maternal arterial blood. The difference in partial pressures between maternal and fetal blood is not large, as the partial pressure of oxygen in fetal blood at the placenta is about 20 mm Hg. Therefore, there is not as much diffusion of oxygen into the fetal blood supply. The fetus' hemoglobin overcomes this problem by having a greater affinity for oxygen than maternal hemoglobin (Figure 22.27). Both fetal and adult hemoglobin have four subunits, but two of the subunits of fetal hemoglobin have a different structure that causes fetal hemoglobin to have a greater affinity for oxygen than does adult hemoglobin. Q: How is blood supplied from the mother to the fetus? Choices: - brain stem - vagina - spinal cord - umbilical cord A:
umbilical cord
(Question)
Answer the following question given this paragraph: The Cytoskeleton Much like the bony skeleton structurally supports the human body, the cytoskeleton helps the cells to maintain their structural integrity. The cytoskeleton is a group of fibrous proteins that provide structural support for cells, but this is only one of the functions of the cytoskeleton. Cytoskeletal components are also critical for cell motility, cell reproduction, and transportation of substances within the cell. The cytoskeleton forms a complex thread-like network throughout the cell consisting of three different kinds of proteinbased filaments: microfilaments, intermediate filaments, and microtubules (Figure 3.18). The thickest of the three is the microtubule, a structural filament composed of subunits of a protein called tubulin. Microtubules maintain cell shape and structure, help resist compression of the cell, and play a role in positioning the organelles within the cell. Microtubules also make up two types of cellular appendages important for motion: cilia and flagella. Cilia are found on many cells of the body, including the epithelial cells that line the airways of the respiratory system. Cilia move rhythmically; they beat constantly, moving waste materials such as dust, mucus, and bacteria upward through the airways, away from the lungs and toward the mouth. Beating cilia on cells in the female fallopian tubes move egg cells from the ovary towards the uterus. A flagellum (plural = flagella) is an appendage larger than a cilium and specialized for cell locomotion. The only flagellated cell in humans is the sperm cell that must propel itself towards female egg cells. Q: In humans, the sperm cell is the only cell with what structure that enables motility? Choices: - eukaryotic - False Cell - sporangia - flagella A:
(Answer)
flagella
Ques: Answer the following question given this paragraph: Radon is also radioactive and can easily be inhaled into the lungs. Over time, this internal radon exposure can lead to the development of lung cancer. The incidence of lung cancer in smokers exposed to radon is much higher than that in non-smokers exposed to radon since smoking has already produced some lung damage, and the radon simply makes the damage worse. Radon exposure is highest in homes lacking good air circulation to move the gas out of the residence. There are a number of inexpensive approaches to decreasing your exposure to radon. A good start is to test your living area for radon with a radon test kit. Q: Smoking increases the risk of cancer from what radioactive gas that can also be detected with a test kit for your home? Choices: - arsenic - carbon monoxide - carbon dioxide - radon A:
Ans: radon
(Q).
Answer the following question given this paragraph: Jami Dwyer. Deforestation creates significant increases in carbon dioxide levels around the world . Public Domain. Q: Does deforestation increase or decrease carbon dioxide levels around the world? Choices: - accelerate - eliminate - decrease - increase A:
(A).
increase
Ques:Answer the following question given this paragraph: Protists Practice Questions 3. Found in many products, such as Petri dishes, agar is made from mucilagnious material in seaweed. Of the six phyla of algae, which phyllum/phyla would agar be made from? 4. Which of the following adjectives describe the major food source of Euglenophytes without an eyespot? a) photoautotrophic b) photoheterotrophic c) chemoautotrophic d) chemoheterotrophic e) B or C f) C or D 5. Can coral reefs exist in nutrient-poor areas? Explain. Q: Found in many products, such as petri dishes, agar is made from mucilagnious material in this? Choices: - fungi - seawater - gelatin - seaweed A:

Ans:seaweed
Answer the following question given this paragraph: Gilbert Lewis (1875-1946) proposed a third theory of acids and bases that is even more general than either the Arrhenius or Brnsted-Lowry theories. A Lewis acid is a substance that accepts a pair of electrons to form a covalent bond. A Lewis base is a substance that donates a pair of electrons to form a covalent bond. So, a Lewis acid-base reaction is represented by the transfer of a pair of electrons from a base to an acid. A hydrogen ion, which lacks any electrons, accepts a pair of electrons. It is an acid under both the Brnsted-Lowry and Lewis definitions. Ammonia consists of a nitrogen atom as the central atom with a lone pair of electrons. The reaction between ammonia and the hydrogen ion can be depicted as shown in the Figure below . Q: A lewis acid is a substance that accepts a pair of electrons to form what? Choices: - accretion bond - functionality bond - ambivalent bond - covalent bond A:
covalent bond