Answer:
A protoplanetary disk is round rotating object which is made of dense gas. This surrounds the newly formed star, Herbig star and T tauri star.
It is also considered as a accreation because the remnants like gases and other materials fall from them on to the star.The extremely illuminating protoplanetary disk are known as the proplyds.
Whereas the nebula can be defined as the densely packed hydrogen and other gases that collapse under the force of gravity. The Nebula starts becoming smaller and smaller because the particles of gases collapse and get closer to each other.
Upon force of gravity their friction and heat increases which slowly collapse the star.
Hi lovely,
The answer you're looking for would be Biosphere.
Answer:
fills with blood during arousal and causes an erection.
Explanation:
The corpus spongiosum is a mass of tissue present in the under part of the penis (male sexual structure) that is actively responsible for erection of the penis. The corpus spongiosum, in conjunction with the corpus carvernosa works to maintain erection of the penis in males.
During sexual arousal, the corpus spongiosum, which surrounds the urethra (passage for urine and semen) helps keep the urethra open for semen to be released while the carvernosa becomes filled with blood. This constant flow of blood into the carvernosa makes the penis enlarge and assume an erect position.
The genotype<span> is the set of genes in our DNA which is responsible for a particular trait. The </span>phenotype<span> is the physical expression, or characteristics, of that trait. I'm just defining them but I hope it helps you </span>