Answer: Layer a is 500 million years old.
Explanation:
Trilobite is a member of the group of extinct arthropods found as fossils and they can be identified by the three-lobed as well as three segmented forms. These were the marine animals. These were appeared initially in the Cambrian Period. They used to live 542 million years ago so the fossils can be estimated to be aged of 500 above years old. These animals used to dominate in the sea area.
Deserts, savannas, and grasslands.
Answer:
The correct answer would be - mycobacterium, and streptomyces.
Explanation:
Actinobacteria is a phylum that consists of a group of gram-positive bacteria with cytosine and guanine content in their DNA. These bacteria can be aquatic or land bacteria. Actinobacteria do not have cell wall however they make a non-sptate and mycelium.
Mycobacterium is one of the genera of the actinobacterium phylum. This genus includes pathogenic species in it that cause deadly diseases in humans and other mammals such as leprosy and tuberculosis Whereas streptomyces is another genus of the actinobacteria that is yielded the very first drug to fight with the ancient scourge.
Thus, the correct answer is - mycobacterium and streptomyces.
Answer:
desire (libido), arousal (excitement), orgasm and resolution.
Explanation:
The sexual response cycle has four phases: desire (libido), arousal (excitement), orgasm and resolution.