Answer the following question given this paragraph: Excavata Many of the protist species classified into the supergroup Excavata are asymmetrical, single-celled organisms with a feeding groove "excavated" from one side. This supergroup includes heterotrophic predators, photosynthetic species, and parasites. Its subgroups are the diplomonads, parabasalids, and euglenozoans. Diplomonads Among the Excavata are the diplomonads, which include the intestinal parasite, Giardia lamblia (Figure 23.10). Until recently, these protists were believed to lack mitochondria. Mitochondrial remnant organelles, called mitosomes, have since been identified in diplomonads, but these mitosomes are essentially nonfunctional. Diplomonads exist in anaerobic environments and use alternative pathways, such as glycolysis, to generate energy. Each diplomonad cell has two identical nuclei and uses several flagella for locomotion. Q: Many of the protist species classified into the supergroup excavata are asymmetrical, single-celled organisms with a feeding groove "excavated" from one side. this supergroup includes heterotrophic predators, photosynthetic species, and these? Choices: - insects - reptiles - mammals - parasites A:
parasites
Answer the following question given this paragraph: When lactose is present, the repressor protein does not bind to the operator. This allows RNA polymerase to bind to the promoter and begin transcription. As a result, the lac genes are expressed, and lactose is digested. Q: When lactose is present in the cell, what allows the lac genes to be expressed? Choices: - concentration of repressor protein - binding of expressor protein - the addition of water - nonbinding of repressor protein A:
nonbinding of repressor protein
Q: Answer the following question given this paragraph: Birds have air sacs that store inhaled air and push it into the lungs like bellows. This keeps the lungs constantly filled with oxygenated air. The lungs also contain millions of tiny passages that create a very large surface area for gas exchange with the blood (see Figure below ). Q: Birds have air sacs that store inhaled air and push it into their what? Choices: - beaks - bones - abdomens - lungs A:
A: lungs
Question: Answer the following question given this paragraph: Conversely, very large forces are created by liquids and solids when they try to expand but are constrained from doing sowhich is equivalent to compressing them to less than their normal volume. This often occurs when a contained material warms up, since most materials expand when their temperature increases. If the materials are tightly constrained, they deform or break their container. Another very common example occurs when water freezes. Water, unlike most materials, expands when it freezes, and it can easily fracture a boulder, rupture a biological cell, or crack an engine block that gets in its way. Other types of deformations, such as torsion or twisting, behave analogously to the tension, shear, and bulk deformations considered here. Q: Conversely, very large forces are created by liquids and solids when they try to expand but are constrained from doing sowhich is equivalent to compressing them to less than their normal volume. this often occurs when a contained material warms up, since most materials expand when they do this? Choices: - increase density - increase mass - decrease temperature - increase temperature A:
Answer: increase temperature
*Question*
Answer the following question given this paragraph: Since life began on Earth, there have been several major mass extinctions. If you look closely at the geological time scale, you will find that at least five major mass extinctions have occurred in the past 540 million years. In each mass extinction, over 50% of animal species died. The total number of mass extinctions could be as high as 20. Q: What events, resulting in death of over half of animal species, have occurred on earth at least five times in the past 540 million years? Choices: - mass migrations - microevolutions - spontaneous mutations - mass extinctions A:
**Answer**
mass extinctions
*Question*
Answer the following question given this paragraph: The ears are also responsible for the sense of balance. Balance is the ability to sense and maintain body position. The semicircular canals inside the ear (see Figure above ) contain fluid that moves when the head changes position. Tiny hairs lining the semicircular canals sense movement of the fluid. In response, they send nerve impulses to the vestibular nerve, which carries the impulses to the brain. The brain interprets the impulses and sends messages to the peripheral nervous system. This system maintains the body's balance by triggering contractions of skeletal muscles as needed. Q: What external feature in human beings is responsible for balance? Choices: - tails - brain - hands - ears A:
**Answer**
ears