Q: What includes all the biotic and abiotic factors in an area and how they interact? Read this paragraph and choose the correct option from the provided answers: An ecosystem is a unit of nature. It consists of all the biotic and abiotic factors in an area and all the ways in which they interact. Choices: - biome - habitat - tundra - ecosystem A:
ecosystem

(Question)
Q: Osmosis is driven by the imbalance of what? Read this paragraph and choose the correct option from the provided answers: Osmosis is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration. Osmosis is driven by the imbalance in water concentration. For example, water is more concentrated in your body than in Epsom salt. When you soak a swollen ankle in Epsom salt, the water moves out of your body into the lower-concentration region in the salt. Similarly, dialysis is the transport of any other molecule through a semipermeable membrane due to its concentration difference. Both osmosis and dialysis are used by the kidneys to cleanse the blood. Osmosis can create a substantial pressure. Consider what happens if osmosis continues for some time, as illustrated in Figure 12.23. Water moves by osmosis from the left into the region on the right, where it is less concentrated, causing the solution on the right to rise. This movement will continue until the pressure gh created by the extra height of fluid on the right is large enough to stop further osmosis. This pressure is called a back pressure. The back pressure. Choices: - precipitation - isolation - evaporation - water concentration A:
(Answer)
water concentration

Ques: Q: What hits the eardrum and causes it to vibrate? Read this paragraph and choose the correct option from the provided answers: The eardrum is like the head of a drum. It is a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. Choices: - cilia - decibels - microwaves - sound waves A:
Ans: sound waves

(Q).
Q: Within the first 8 weeks of gestation, a developing embryo establishes the rudimentary structures of all of its organs and tissues from the ectoderm, mesoderm, and endoderm. this process is called what? Read this paragraph and choose the correct option from the provided answers: Within the first 8 weeks of gestation, a developing embryo establishes the rudimentary structures of all of its organs and tissues from the ectoderm, mesoderm, and endoderm. This process is called organogenesis. Like the central nervous system, the heart also begins its development in the embryo as a tube-like structure, connected via capillaries to the chorionic villi. Cells of the primitive tube-shaped heart are capable of electrical conduction and contraction. The heart begins beating in the beginning of the fourth week, although it does not actually pump embryonic blood until a week later, when the oversized liver has begun producing red blood cells. (This is a temporary responsibility of the embryonic liver that the bone marrow will assume during fetal development. ) During weeks 45, the eye pits form, limb buds become apparent, and the rudiments of the pulmonary system are formed. During the sixth week, uncontrolled fetal limb movements begin to occur. The gastrointestinal system develops too rapidly for the embryonic abdomen to accommodate it, and the intestines temporarily loop into the umbilical cord. Paddle-shaped hands and feet develop fingers and toes by the process of apoptosis (programmed cell death), which causes the tissues between the fingers to disintegrate. By week 7, the facial structure is more complex and includes nostrils, outer ears, and lenses (Figure 28.15). By the eighth week, the head is nearly as large as the rest of the embryo's body, and all major brain structures are in place. The external genitalia are apparent, but at this point, male and female embryos are indistinguishable. Bone begins to replace cartilage in the embryonic skeleton through the process of ossification. By the end of the embryonic period, the embryo is approximately 3 cm (1.2 in) from crown to rump and weighs approximately 8 g (0.25 oz). Choices: - abiogenesis - biosynthesis - parthenogenesis - organogenesis A:
(A).
organogenesis

Ques:Q: Capillaries in the chorionic villi filter fetal wastes out of the blood and return clean, oxygenated blood to the fetus through what? Read this paragraph and choose the correct option from the provided answers: The placenta develops throughout the embryonic period and during the first several weeks of the fetal period; placentation is complete by weeks 1416. As a fully developed organ, the placenta provides nutrition and excretion, respiration, and endocrine function (Table 28.1 and Figure 28.12). It receives blood from the fetus through the umbilical arteries. Capillaries in the chorionic villi filter fetal wastes out of the blood and return clean, oxygenated blood to the fetus through the umbilical vein. Nutrients and oxygen are transferred from maternal blood surrounding the villi through the capillaries and into the fetal bloodstream. Some substances move across the placenta by simple diffusion. Oxygen, carbon dioxide, and any other lipid-soluble substances take this route. Other substances move across by facilitated diffusion. This includes water-soluble glucose. The fetus has a high demand for amino acids and iron, and those substances are moved across the placenta by active transport. Maternal and fetal blood does not commingle because blood cells cannot move across the placenta. This separation prevents the mother's cytotoxic T cells from reaching and subsequently destroying the fetus, which bears "non-self" antigens. Further, it ensures the fetal red blood cells do not enter the mother's circulation and trigger antibody development (if they carry "non-self" antigens)at least until the final stages of pregnancy or birth. This is the reason that, even in the absence of preventive treatment, an Rh mother doesn't develop antibodies that could cause hemolytic disease in her first Rh+ fetus. Although blood cells are not exchanged, the chorionic villi provide ample surface area for the two-way exchange of substances between maternal and fetal blood. The rate of exchange increases throughout gestation as the villi become thinner and increasingly branched. The placenta is permeable to lipid-soluble fetotoxic substances: alcohol, nicotine, barbiturates, antibiotics, certain pathogens, and many other substances... Choices: - separates vein - Back Vein - skin vein - umbilical vein A:

Ans:umbilical vein

Q: The earliest vertebrates were jawless what? Read this paragraph and choose the correct option from the provided answers: The earliest vertebrates were jawless fish. They evolved about 550 million years ago. They were probably similar to modern hagfish (see Table above ). The tree diagram in Figure below summarizes how vertebrates evolved from that time forward. Choices: - mammals - dinosaurs - reptiles - fish A:
fish