ACT Science Practice Test - 2 - online test

Fatty acids are organic lipids that are found in many foods people eat, such as beef, milk and corn. These fats differ in their fatty acid composition and are considered to be either saturated or unsaturated fats. Saturated fats have no carbon double bonds, whereas unsaturated fats have one (monounsaturated) or more (polyunsaturated) carbon double bonds (Figure 1). Chemical compounds with double bonds assume different geometrical shapes depending upon the configuration of the double bond. Some examples of typical fatty acids are shown in Figure 2. Different shapes of a compound are called isomers. Unsaturated fatty acids can assume the cis or trans isomer. The cis isomer refers to when hydrogen atoms are on the same side of a carbon double bond, whereas the trans isomer refers to when hydrogen atoms are on opposite sides of a carbon double bond. Trans fatty acids are a major concern to consumers around the world as they may contribute to coronary heart disease by raising LDL cholesterol (i.e., bad cholesterol) levels and lowering HDL (i.e., good cholesterol) levels. Some rans fatty acids come from dairy and meat, but most come from hydrogenated vegetable and fish oils. Some people believe that unsaturated fats are healthier for you than saturated fats, however, it is best to limit your daily intake of all kinds of fats.

Amy is studying the properties of lipids in her biochemistry class and these lectures have sparked her interest in fatty acid content in common foods. For her final term project, she decided to run experiments in the lab to determine the saturated, monounsaturated and polyunsaturated fatty acid content in different foods that she often eats. Figures 3 and 4 show her results.

Science lesson Science Practice Test 2 exam questions 1. question pragraph

Science lesson Science Practice Test 2 exam questions 1. question pragraph

Science lesson Science Practice Test 2 exam questions 1. question pragraph

Science lesson Science Practice Test 2 exam questions 1. question pragraph

What is the percentage of monounsaturated fats in ham?

75%

25%

40%

50%

See Figure 4. Ham contains 50% monounsaturated fats.

Amy has just broken up with her boyfriend and wants to eat some comfort food (foods highest in saturated fats). What foods should she eat?

cake, beef, and a tall glass of 2% milk

cheese, ice cream, and cake

turkey, ice cream, and sunflower seeds

butter, chocolate bar, and almonds

See Figures 3 and 4. All three items―cheese, ice cream, and cake―have the highest percentage of saturated fats.

Which compound is monounsaturated with a cis configuration?

Science lesson Science Practice Test - 2 exam questions 3 question 1 Answer

Science lesson Science Practice Test - 2 exam questions 3 question 2 Answer

Science lesson Science Practice Test - 2 exam questions 3 question 3 Answer

Science lesson Science Practice Test - 2 exam questions 3 question 4 Answer

B has 1 double bond (monosaturated) and both hydrogens are on the same side of that bond, hence a cis configuration.

Note: Be sure you are not counting the double bond from the fatty acid portion.

Which food has the greatest amount of polyunsaturated fats?

sunflower seeds

soybean oil

turkey

2% milk

See Figure 3: Sunflower seeds have 70% polyunsaturated fats.

If you ate almonds, what percentage of saturated fats would you have consumed?

20%

65%

15%

30%

See Figure 3. Almonds contain 15% saturated fats.

Humans spend about one third of their lives sleeping, however, the amount of time we spend during each sleep stage varies with age. Children spend approximately 60% of their time sleeping, whereas adults spend about 37% of their time sleeping. As we age, the amount of time spent sleeping doesn’t change, however, we experience less deep sleep. During sleep, we experience slowDwave and paradoxical or rapid ye movement (REM) sleep. SlowDwave sleep has several stages. As we begin to fall asleep, we go from light sleep (stage 1) to deep sleep (stage 4), which lasts for about 30D45 minutes. After this time, we go back through the same stages of sleep in the same amount of time, but in the reverse order. REM follows, which lasts about 10D15 minutes. We continue to repeat this cycle throughout the duration of our sleep. Slow wave sleep comprises 80% of a mature person’s sleep cycle, whereas REM comprises 20%.

Electroencephalograms (EEGs) are used to “see” the brain wave patterns of subjects while they sleep. The Sleep Institute in Wyoming, New Jersey, has patients that suffer from different sleep disorders. When a patient is admitted, their sleep wave patterns are measured using an EEG before the patient is directed to the appropriate sleep psychologist for treatment. Control subjects (people with normal brain wave patterns), at the Institute, are used as a baseline for measuring people with sleep disorders such as Insomnia, Sleep Apnea, Narcolepsy and Restless Leg Syndrome (RLS). The following is an EEG of a control subject.

Science lesson Science Practice Test 2 exam questions 6. question pragraph

What percentage of time does an adult spend in paradoxical sleep?

30%

80%

50%

20%

See supporting documentation. Paradoxical sleep is REM sleep, which comprises 20% of an adult’s sleep cycle.

Science lesson Science Practice Test - 2 exam questions 7 questionWhich pie chart shows how much time a child spends asleep and awake?

B

D

C

A

See supporting documentation. Children spend approximately 60% of their time sleeping (A), whereas adults spend about 37% of their time sleeping (C). As we age, the amount of time spent sleeping doesn’t change; however, we experience less deep sleep (B). The last information (D) is made up and cannot be for a child because sleep takes up 75% of the chart.

Note: Be sure to read carefully. This question was about the sleep patterns of a child and there is information in the passage concerning both children and adults. This can be confusing.

Which EEG pattern represents deep sleep?

Science lesson Science Practice Test - 2 exam questions 8 question 1 Answer

Science lesson Science Practice Test - 2 exam questions 8 question 2 Answer

Science lesson Science Practice Test - 2 exam questions 8 question 3 Answer

Science lesson Science Practice Test - 2 exam questions 8 question 4 Answer

In the supporting documentation, it mentions that stage 4 is deep sleep. See Figure 1. It shows the brain wave pattern for stage 4.

Science lesson Science Practice Test - 2 exam questions 9 questionWhich EEG pattern represents slow-wave sleep?

A

B and C

A, B, and C

D

Slow-wave sleep includes stages 1 to 4, which are shown by A, B, and C in the image. D is not included because it represents REM sleep.

(Be sure to see both the “image” and the “document” attached for all of the necessary information to answer this question.)

Science lesson Science Practice Test - 2 exam questions 10 questionWhich pie chart shows how much time an elderly person spends asleep and awake?

A

B

D

C

See supporting documentation. Children spend approximately 60% of their time sleeping (A). As adults, that amount decreases to about 37% and choice C is the only pie chart that shows approximately that amount. The data presented in (B) and (D) cannot represent the elderly as sleep takes up a majority of each chart.

Science lesson Science Practice Test - 2 exam questions 11 questionTheodore goes to bed at 10 p.m. and is awake at 7 a.m. The included graph represents the overnight sleep cycles through which he oscillates. The sleep stages on the Y axis (vertical axis) have purposefully been omitted. Which letter represents one complete sleep cycle? (Hint: To complete this question, you must know where the different sleep stages belong on the Y axis.)

C

D

B

A

See supporting documentation. The first sleep stage, awake, is given in the question: Theodore is awake at 7 a.m., so the highest point on the graph must be “awake”. A shows stages 4 to 1, then REM, then stages 1 to 4; B shows more than one cycle―REM to stage 4, stage 4 to 1, REM, stages 1 to 4; C shows more than one cycle―stages 2 to 4, then stage 4 to 1, REM, then stages 1 to 4; D shows 1 complete cycle―the sleep cycle is stage 1 to 4, then stage 4 to 1, then REM.