Q: Shark teeth likely evolved from the jagged scales that cover their skin, called what? Read this paragraph and choose the correct option from the provided answers: Chondrichthyes: Cartilaginous Fishes The clade Chondrichthyes is diverse, consisting of sharks (Figure 29.11), rays, and skates, together with sawfishes and a few dozen species of fishes called chimaeras, or "ghost" sharks. " Chondrichthyes are jawed fishes that possess paired fins and a skeleton made of cartilage. This clade arose approximately 370 million years ago in the early or middle Devonian. They are thought to be descended from the placoderms, which had skeletons made of bone; thus, the cartilaginous skeleton of Chondrichthyes is a later development. Parts of shark skeleton are strengthened by granules of calcium carbonate, but this is not the same as bone. Most cartilaginous fishes live in marine habitats, with a few species living in fresh water for a part or all of their lives. Most sharks are carnivores that feed on live prey, either swallowing it whole or using their jaws and teeth to tear it into smaller pieces. Shark teeth likely evolved from the jagged scales that cover their skin, called placoid scales. Some species of sharks and rays are suspension feeders that feed on plankton. Choices: - heterotroph scales - hook scales - pinworm scales - placoid scales A:
placoid scales

(Question)
Q: A mitotic spindle forms from the centrioles and passes through the nuclear membrane, which remains intact. chromosomes attach to the mitotic spindle, which separates the chromosomes and does what? Read this paragraph and choose the correct option from the provided answers: A mitotic spindle forms from the centrioles and passes through the nuclear membrane, which remains intact. Chromosomes attach to the mitotic spindle, which separates the chromosomes and elongates the cell. Choices: - manipulates the cell - migrates the cell - destroys the cell - elongates the cell A:
(Answer)
elongates the cell

Ques: Q: What is the force that slows down or stops motion? Read this paragraph and choose the correct option from the provided answers: Choices: - resistance - tension - thrust - friction A:
Ans: friction

(Q).
Q: What is the key to the demographic transition? Read this paragraph and choose the correct option from the provided answers: Choices: - higher birth rates - higher expatriation - higher death rates - reduced family size A:
(A).
reduced family size

Ques:Q: What is the property by which water molecules stick together? Read this paragraph and choose the correct option from the provided answers: Water has some unusual properties due to its hydrogen bonds. One property is cohesion , the tendency for water molecules to stick together. The cohesive forces between water molecules are responsible for the phenomenon known as surface tension . The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. For example, if you drop a tiny amount of water onto a very smooth surface, the water molecules will stick together and form a droplet, rather than spread out over the surface. The same thing happens when water slowly drips from a leaky faucet. The water doesn't fall from the faucet as individual water molecules but as droplets of water. The tendency of water to stick together in droplets is also illustrated by the dew drops in Figure below . Choices: - plasticity - vitality - tension - cohesion A:

Ans:cohesion

Ques: Q: What organ has four ventricles, all of which developed from the original hollow space within the neural tube? Read this paragraph and choose the correct option from the provided answers: The Ventricles There are four ventricles within the brain, all of which developed from the original hollow space within the neural tube, the central canal. The first two are named the lateral ventricles and are deep within the cerebrum. These ventricles are connected to the third ventricle by two openings called the interventricular foramina. The third ventricle is the space between the left and right sides of the diencephalon, which opens into the cerebral aqueduct that passes through the midbrain. The aqueduct opens into the fourth ventricle, which is the space between the cerebellum and the pons and upper medulla (Figure 13.18). Choices: - heart - liver - bladder - brain A:
Ans:
brain