2017年AP生物（选择题+简答题）真题及答案PDF下载

2017年AP生物（选择题+简答题）真题及答案PDF下载

2017年AP生物选择题真题如下：

1. The food web represented above does not include bacteria and fungi. Which of the following best describes a consequence of having no bacteria and fungi in the food web?

(A) Grasses will have no direct access to chemical components recycled from dead organisms.

(B) Rabbits will have no direct access to energy absorbed from secondary consumers.

(C) Shrews will have no direct access to matter transferred from tertiary consumers.

(D) Hawks will have no direct access to nitrogen acquired from the atmosphere.

2. The following DNA sequence is a small part of the coding (nontemplate) strand from the open reading frame of the β-hemoglobin gene. Given the codon chart listed below, what would be the effect of a mutation that deletes the G at the beginning of the DNA sequence?

(A) The mutation precedes the gene, so no changes would occur.

(B) Lysine (lys) would replace glutamine (gin), but there would be no other changes.

(C) The first amino acid would be missing, but there would be no other change to the protein.

(D) The reading frame of the sequence would shift, causing a change in the amino acid sequence after that point.

3. A widely accepted hypothesis about the origin of life on Earth is that life arose approximately 3.5 billion years ago as the result of a complex sequence of chemical reactions that took place spontaneously in Earth's atmosphere. Another hypothesis about the origin of life suggests that life began somewhere else in the universe and arrived on Earth by chance.

Which of the following questions might scientists ask to most reliably determine if there has ever been life on Mars?

(A) How far from Earth was Mars 3.5 billion years ago?

(B) Is there scientific proof that Earth ever had an oxygen-free atmosphere?

(C) Did Mars have the elements present in its atmosphere to support life?

(D) Was there oxygen gas on Mars 3.5 billion years ago?

4. Cortisol is a hormone produced in response to stress, including starvation, in humans. Which of the following is most likely an immediate effect of a starvation-induced increase in cortisol secretion?

(A) Increased activation of the immune system

(B) Increased urine production by the kidneys

(C) Increased bone and collagen formation

(D) Increased mobilization of fatty acids from fat cells

5. Ciprofloxacin is given as an antibiotic to healthy livestock to promote efficient weight gain. Strains of the bacterium Campylobacter jejuni naturally colonize the digestive tracts of livestock, and the C. jejuni can be transferred to people through the handling and consumption of contaminated meat. People infected with C. jejuni also are treated with ciprofloxacin.

Which of the following is the most likely consequence of adding ciprofloxacin to animal feed?

(A) Naturally occurring strains of C. jejuni will reproduce more rapidly in the digestive tracts of livestock, reducing the risk of food-borne illnesses in people.

(B) Ciprofloxacin-resistant strains of C. jejuni will have a selective advantage in the digestive tracts of livestock, increasing the risk of serious infections in people.

(C) Ciprofloxacin-sensitive strains of C. jejuni will be consumed in meat that contains a chemical that inhibits bacterial growth, reducing the risk of food poisoning in people.

(D) Actively growing strains of C. jejuni will metabolize the nutrients in meat produced by livestock operations, increasing the risk of protein deficiencies in people.

2017年AP生物选择题真题余下省略！

2017年AP生物简答题真题如下：

1. Fireflies are a group of insects that possess a lantern organ composed of numerous light-producing cells (photocytes) in their abdomens. The light is produced by a chemical reaction involving the light-emitting organic compound luciferin. In each photocyte, luciferin is activated in an ATP-dependent reaction that is catalyzed by the enzyme luciferase. In the presence of oxygen, the activated luciferin emits light as it is converted to oxyluciferin (Figure 1).

The flashes of light are controlled by neurons that innervate the lantern organ. Activated neurons stimulate the release of nitric oxide (NO), an inhibitor of the electron transport chain. The pattern of light flashes (Figure 2) emitted by males is a signal to attract females as a component of mating behavior. Different species of firefly display different patterns of flashes (Figure 3). The evolutionary relatedness of these species, as determined using multiple morphological characteristics, is shown in Figure 4.

(a) Identify the main source of the ATP used for activating luciferin, as shown in Figure 1, and describe the effect of the release of NO on oxygen levels in the photocyte during flashing.

(b) Describe TWO differences in the flash patterns of P. pyralis and P. knulli. Justify the use of differences in flash signal patterns as evidence to support the claim that P. pyralis and P. knulli are different species.

(c) Use the template provided to construct a cladogram based on the data in Figure 3. Circle the position on the cladogram that represents the outgroup.

(d) Evaluate the data used to construct the cladogram in Figure 4 and the cladogram you constructed in part (c) and identify which cladogram is most likely to represent a more accurate phylogeny of the organisms. Propose ONE type of additional data that that could be used to refine the phylogeny of these species.

2017年AP生物简答题真题余下省略！

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