Answer: Sebum
Explanation: Sebaceous gland secretes sebum which is a chemical mediator that helps in lubrication and protection.
The sebaceous gland is present in skin and produces oil which is an endogenous mediator which provides a seal for the harmful microorganism so that they cannot the body through skin.
In this way it also protects the sweat gland which produces sweat.some of the bacteria that causes acne uses lipase to degrade sebum and causes infection.
Hence, the correct answer is option B
Mulch<span>, a type of protective covering which is in direct contact with the ground, provides more protection than canopy cover. It can vary from straw, to compost, to wood chips, or saw dust. Spread evenly onto the ground, mulch helps to reduce water evaporation, control weeds, and enrich the soil. It is also significant in protecting soil where vegetation has not had ample time to establish itself. By absorbing the destructive forces of raindrops and wind, mulch reduces erosion until the the seedlings mature enough to provide their own protective cover. thats all I know</span>
Answer:
The depth at which Drew found the algae
Explanation:
The dependent variable was the depth at which he found the algae, because that is what he measured on each day.
The independent variable was the sky conditions, since that changed from clear to cloudy, which impacted the dependent variable/the depth of the algae.
