Q: Photoautotrophs use what energy source to self-manufacture their own food? Read this paragraph and choose the correct option from the provided answers: every organism uses to power its metabolism. In brief, the energy of sunlight is captured and used to energize electrons, which are then stored in the covalent bonds of sugar molecules. How long lasting and stable are those covalent bonds? The energy extracted today by the burning of coal and petroleum products represents sunlight energy captured and stored by photosynthesis almost 200 million years ago. Plants, algae, and a group of bacteria called cyanobacteria are the only organisms capable of performing photosynthesis (Figure 8.2). Because they use light to manufacture their own food, they are called photoautotrophs (literally, "self-feeders using light"). Other organisms, such as animals, fungi, and most other bacteria, are termed heterotrophs ("other feeders"), because they must rely on the sugars produced by photosynthetic organisms for their energy needs. A third very interesting group of bacteria synthesize sugars, not by using sunlight's energy, but by extracting energy from inorganic chemical compounds; hence, they are referred to as chemoautotrophs. Choices: - water - chlorophyll - air - light A:
light

Q: What structure of a cell is enclosed by a membrane and contains most of the cell's dna? Read this paragraph and choose the correct option from the provided answers: Besides the four parts listed above, many cells also have a nucleus. The nucleus of a cell is a structure enclosed by a membrane that contains most of the cell's DNA. Cells are classified in two major groups based on whether or not they have a nucleus. The two groups are prokaryotic cells and eukaryotic cells. Choices: - vacuole - ribosome - epidermis - nucleus A:
nucleus

Q: What stage in human males lasts from about ages 12 to 18 years and is controlled by hormones? Read this paragraph and choose the correct option from the provided answers: The male reproductive system forms before birth but does not become capable of reproduction until it matures during puberty. Puberty lasts from about ages 12 to 18 years and is controlled by hormones. Choices: - childhood - adolescence - maturity - puberty A:
puberty