Answer:
Option A, most closely related to mammals
Explanation:
Insects like arthropods and molluscs have an open circulatory system and thus do have a distinguishable heart. Fish has two chambered heart. Reptiles have three chambered heart. Amphibians too have a three chambered heart.
All mammals and fish have four chambered heart. The right and left sides of the chambers have restricted entry and hence remain intact from each other
Hence, option A is correct
The steeper the slope of the track the quicker the toy car will accelerate.
The Law of Superposition.
The Law of Superposition states that each layer is younger than the one beneath it.
Answer:
Codeine
Explanation:
Codeine is an opiate and is used to treat mild and moderate pain. It is also the main ingredient in prescription based cough suppressant. It belongs to a class of drugs known as opioid analgesics.
Codeine is a naturally occurring phenanthrene alkaloid with opioid agonist and can be extracted directly from the plant although most codeine is synthesized from the opium poppy.