Answer:
An immune response is a reaction which occurs within an organism for the purpose of defending against foreign invaders. The first contact that an organism has with a particular antigen will result in the production of effector T and B cells which are activated cells that defend against the pathogen.
Explanation:
Bladder is definitely the word
a neurosecretory cell in the hypothalamus.
Answer:
The mass of a star determines its life cycle, that is, more the mass, shorter will be its life cycle. The mass of the star is determined by the concentration of matter, which is found within its nebula. In the nebula, with time, the hydrogen gas comes in close proximity with each other due to gravity and starts to spin.
With the brisk spinning, the gas heats up and turns into a protostar. The temperature now reaches 15,000,000 degrees and within the core of the cloud, the phenomenon of nuclear fusion takes place. The cloud now contracts a little, starts to glow brightly, and turns stable. The cloud now becomes a prime sequence star, and will stay in this phase for millions of years, the Sun of our galaxy is in this stage at the moment.
An aloe vera plant possessing a trait for extra thick leaves survives very long droughts in deserts, while and aloe vera plant that doesn't have thick leaves doesn't.