Compared with innate defenses, adaptive defenses
(a) Do not distinguish between one threat and another
(b) Are always present at birth
(c) Protect against threats on an individual basis
(d) Deny the entry of pathogens to the body

Verified step by step guidance

1. Step 1: Understand the difference between innate and adaptive defenses. Innate defenses are the body's first line of defense and respond to threats in a general, non-specific way, while adaptive defenses are specific and tailored to particular pathogens.
2. Step 2: Analyze option (a): 'Do not distinguish between one threat and another.' This describes innate defenses, which respond broadly, so adaptive defenses actually do distinguish between different threats.
3. Step 3: Analyze option (b): 'Are always present at birth.' Innate defenses are present at birth, but adaptive defenses develop and improve after exposure to specific pathogens.
4. Step 4: Analyze option (c): 'Protect against threats on an individual basis.' Adaptive defenses are specific to particular pathogens and provide targeted protection, which matches this description.
5. Step 5: Analyze option (d): 'Deny the entry of pathogens to the body.' This is primarily a function of innate defenses like skin and mucous membranes, not adaptive defenses.

Key Concepts

Innate Defenses

Innate defenses are the body's first line of defense against pathogens, present from birth. They provide a general, non-specific protection by recognizing common features of pathogens but do not target specific threats individually.

Adaptive Defenses

Adaptive defenses are specialized immune responses that develop after exposure to specific pathogens. They recognize and remember individual threats, allowing for targeted and more effective protection upon subsequent encounters.

Specificity and Memory in Immunity

Adaptive immunity is characterized by its ability to distinguish between different pathogens and remember them. This specificity enables the immune system to mount a tailored response to each threat and improve defense over time.