Answer the following question given this paragraph: 27.3 Development of the Male and Female Reproductive Systems The reproductive systems of males and females begin to develop soon after conception. A gene on the male's Y chromosome called SRY is critical in stimulating a cascade of events that simultaneously stimulate testis development and repress the development of female structures. Testosterone produced by Leydig cells in the embryonic testis stimulates the development of male sexual organs. If testosterone is not present, female sexual organs will develop. Whereas the gonads and some other reproductive tissues are considered bipotential, the tissue that forms the internal reproductive structures stems from ducts that will develop into only male (Wolffian) or female (Mullerian) structures. To be able to reproduce as an adult, one of these systems must develop properly and the other must degrade. Further development of the reproductive systems occurs at puberty. The initiation of the changes that occur in puberty is the result of a decrease in sensitivity to negative feedback in the hypothalamus and pituitary gland, and an increase in sensitivity of the gonads to FSH and LH stimulation. These changes lead to increases in either estrogen or testosterone, in female and male adolescents, respectively. The increase in sex steroid hormones leads to maturation of the gonads and other reproductive organs. The initiation of spermatogenesis begins in boys, and girls begin ovulating and menstruating. Increases in sex steroid hormones also lead to the development of secondary sex characteristics such as breast development in girls and facial hair and larynx growth in boys. Q: What is produced by leydig cells in the embryonic testis and stimulates the development of male sexual organs? Choices: - androgen - insulin - estrogen - testosterone A:
testosterone
(Question)
Answer the following question given this paragraph: Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which the change is occurring. It may reflect a change in speed, a change in direction, or both. Like velocity, acceleration is a vector. Q: What is the measure of the change in velocity of a moving object called? Choices: - inclination - force - stimulation - acceleration A:
(Answer)
acceleration
Ques: Answer the following question given this paragraph: Bears get their energy from their food. Brown bears eat a varied diet, from nuts and berries to fish and other animals. When bears eat a berry, they are obtaining energy that the plant originally captured from the sun. Even when a bear eats another animal, the energy in that animal ultimately came from eating a producer that captured the sun's energy. Q: Which is the ultimate energy source in a bear's food chain? Choices: - decomposers - plants - heat - sun A:
Ans: sun
(Q).
Answer the following question given this paragraph: The shape of the path of an object undergoing projectile motion in two dimensions is a parabola. Q: The shape of the path of an object undergoing projectile motion in two dimensions is a what? Choices: - orbit - circle - radius - parabola A:
(A).
parabola
Ques:Answer the following question given this paragraph: Roots: Support for the Plant Roots are not well preserved in the fossil record; nevertheless, it seems that they did appear later in evolution than vascular tissue. The development of an extensive network of roots represented a significant new feature of vascular plants. Thin rhizoids attached the bryophytes to the substrate. Their rather flimsy filaments did not provide a strong anchor for the plant; neither did they absorb water and nutrients. In contrast, roots, with their prominent vascular tissue system, transfer water and minerals from the soil to the rest of the plant. The extensive network of roots that penetrates deep in the ground to reach sources of water also stabilizes trees by acting as ballast and an anchor. The majority of roots establish a symbiotic relationship with fungi, forming mycorrhizae. In the mycorrhizae, fungal hyphae grow around the root and within the root around the cells, and in some instances within the cells. This benefits the plant by greatly increasing the surface area for absorption. Leaves, Sporophylls, and Strobili A third adaptation marks seedless vascular plants. Accompanying the prominence of the sporophyte and the development of vascular tissue, the appearance of true leaves improved photosynthetic efficiency. Leaves capture more sunlight with their increased surface area. In addition to photosynthesis, leaves play another role in the life of the plants. Pinecones, mature fronds of ferns, and flowers are all sporophyllsleaves that were modified structurally to bear sporangia. Strobili are structures that contain the sporangia. They are prominent in conifers and are known commonly as cones: for example, the pine cones of pine trees. Q: The larger surface area of leaves allows them to capture more what? Choices: - pollen - molecules - chlorophyll - sunlight A:

Ans:sunlight
Ques:Answer the following question given this paragraph: Connections of Other Sugars to Glucose Metabolism Glycogen, a polymer of glucose, is an energy storage molecule in animals. When there is adequate ATP present, excess glucose is shunted into glycogen for storage. Glycogen is made and stored in both liver and muscle. The glycogen will be hydrolyzed into glucose monomers (G-1-P) if blood sugar levels drop. The presence of glycogen as a source of glucose allows ATP to be produced for a longer period of time during exercise. Glycogen is broken down into G-1-P and converted into G-6-P in both muscle and liver cells, and this product enters the glycolytic pathway. Q: Where is glycogen created and stored in the body? Choices: - extracts and muscles - Healing Muscles - Sore muscle - liver and muscles A:

Ans:
liver and muscles