Q: What produces almost one-half of the earth's oxygen through photosynthesis? Read this paragraph and choose the correct option from the provided answers: Humans could not live on Earth if it were not for protists. Why? Plant-like protists produce almost one-half of the oxygen on the planet through photosynthesis. Other protists decompose and recycle nutrients that humans need to live. All protists make up a huge part of the food chain. Choices: - prokaryotes - algae - arthropods - protists A:
protists

(Question)
Q: What type of energy from a warm cola results in melting when it is transferred to the much colder ice? Read this paragraph and choose the correct option from the provided answers: How do you cool down a glass of room-temperature cola? You probably add ice cubes to it, as in the Figure below . You might think that the ice cools down the cola, but in fact, it works the other way around. The warm cola heats up the ice. Thermal energy from the warm cola is transferred to the much colder ice, causing it to melt. The cola loses thermal energy in the process, so its temperature falls. Choices: - protective energy - gaseous energy - cyclic energy - thermal energy A:
(Answer)
thermal energy

Ques: Q: What item starts puberty in girls? Read this paragraph and choose the correct option from the provided answers: Puberty in girls starts when the hypothalamus "tells" the pituitary gland to secrete hormones that target the ovaries. Two pituitary hormones are involved: luteinizing hormone (LH) and follicle-stimulating hormone (FSH) . These hormones stimulate the ovary to produce estrogen . Estrogen, in turn, promotes growth and other physical changes of puberty. It stimulates growth and development of the internal reproductive organs, breasts, and pubic hair (see Figure below ). You can watch an animation of these and other changes that girls experience during puberty at this link: http://www. bbc. co. uk/science/humanbody/body/interactives/lifecycle/teenagers/ . Choices: - the ovary - the uterus - the thyroid - the hypothalamus A:
Ans: the hypothalamus

(Q).
Q: About 50% of all animal species died off between the mesozoic and which other era? Read this paragraph and choose the correct option from the provided answers: The most famous mass extinction was 65 million years ago. Between the Mesozoic Era and the Cenozoic Era, about 50% of all animal species died off. This mass extinction is when the dinosaurs became extinct. Most scientists think that the extinction was caused by a giant meteorite that struck Earth. The impact heated the atmosphere until it became as hot as a kitchen oven. Animals roasted. Dust flew into the atmosphere and blocked sunlight for a year or more. This caused a deep freeze and ended photosynthesis. Sulfur from the impact mixed with water in the atmosphere. The result was acid rain. The rain dissolved the shells of the tiny marine plankton that form the base of the food chain. With little food being produced, animals starved. Choices: - jurassic - precambrian - cretaceous - cenozoic A:
(A).
cenozoic

Ques:Q: In science, we need to make observations on various phenomena to form and test what? Read this paragraph and choose the correct option from the provided answers: In science, we need to make observations on various phenomena to form and test hypotheses. Some phenomena can be found and studied in nature, but scientists often need to create an experiment . Experiments are tests under controlled conditions designed to demonstrate something scientists already know or to test something scientists wish to know. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results. The process of designing and performing experiments is a part of the scientific method. Choices: - assumptions - theories - variations - hypotheses A:

Ans:hypotheses

Ques: Q: What mammalian class has the greatest ability to learn? Read this paragraph and choose the correct option from the provided answers: In many ways, humans are unique among mammals. For example, we have bigger brains and a greater ability to learn than any other species in the mammalian class. In many ways, however, we are typical of the mammalian order to which we belong. That order is the Primate Order. To fully understand what it means to be human, you need to know more about this fascinating order of mammals. Choices: - apes - reptiles - rats - humans A:
Ans:
humans