Answer:
Skin acts a defensive and protective layer. It protects the internal body from pathogens, which are disease causing bacteria. The skin can fend off bacteria, particles, foreign bodies, etc.
Explanation:
Answer:
Trace fossils include footprints, trails, burrows, feeding marks, and resting marks.
Explanation:
Answer:There are 11 nonessential amino acids.
Explanation:amino acids are monomers of proteins.proteins are made up of carbon,hydrogen, oxygen and nitrogen.there are 20 amino acids found in proteins.
Plants cam produce all the amino acids they need but animals cannot.
Essential amino acids are those that animals cannot produce by themselves and so need to obtain from their diet.there are 9 in numbers.
Non-essential amino acids are produced by the animals.they are not necessarily non-essential as the name indicates.they are 11 in numbers.
Homointernal adalah hewan yang bersuhu tubuh panas dan tetap hewan-hewan ini adalah:
1)Ikan, terbagi
-ikan hiu
-ikan pari
2)Amfibi terbagi
-Kodok
3)Reptil
-buaya
-kura-kura
4)Burung terbagi
-ayam
-merak
-kasuari
