Meaning: 'Control' means to direct or manage something, indicating that the proteins influence the development of the animal's structure.

Wrong options:

• push: 'Push' implies a forceful action, which does not accurately describe the regulatory role of proteins in development.
• hold: 'Hold' suggests a static action, which does not convey the active regulatory function of the proteins in development.
• elevate: 'Elevate' means to raise or lift, which does not fit the context of managing or directing developmental processes.

Correct answer: In contrast

Explanation: The phrase 'In contrast' serves as a discourse marker that indicates a comparison between two different ideas, effectively highlighting the difference between developmental and housekeeping genes. This fits both grammatically and contextually, as it sets up a clear distinction in the roles of the two types of genes.

Meaning: 'In contrast' means to show how two things are different from each other, emphasizing the differing functions of the two gene types.

Wrong options:

• Correspondingly: This implies a similarity or agreement, which contradicts the intended meaning of highlighting differences between the two types of genes.
• Inclusively: This suggests inclusion, which does not fit the context of contrasting the functions of developmental and housekeeping genes.
• Conversely: While this also indicates a contrast, it is typically used to indicate an opposite situation, which is not the precise relationship being described here.

Correct answer: As

Explanation: The word 'As' functions as a conjunction that introduces a clause, indicating a condition or situation. It fits grammatically and contextually, as it introduces the idea that what follows is a logical conclusion based on the previous statements about mutations in developmental genes.

Meaning: 'As' means 'in the same way that' or 'because,' linking the suspicion about mutations to the consequences that follow.

Wrong options:

• For: This preposition does not appropriately connect the clause to the preceding context, making it grammatically incorrect in this position.
• With: This suggests accompaniment, which does not convey the intended causal relationship between the suspicion and the consequences of mutations.
• Within: This implies being inside something, which does not fit the context of discussing the consequences of mutations.

Correct answer: affect

Explanation: The verb 'affect' is correctly used here to indicate that mutations in housekeeping genes have an impact on health and reproductive success. It fits grammatically as it aligns with the subject 'mutations' and contextually conveys the idea of influence, which is appropriate for the sentence.

Meaning: 'Affect' means to have an influence on something, indicating that these mutations can change the health and reproductive outcomes of the animal.

Wrong options:

• effect: This is a noun meaning a result or outcome, which does not fit grammatically as the sentence requires a verb.
• interrupt: This implies a break or pause, which does not accurately describe the influence of mutations on health and reproductive success.
• defect: This is a noun referring to a flaw or imperfection, which does not fit the context of discussing the impact of mutations.