The heat from hotter object goes to the cooler object. when they reach the same temperature the heat flow will stop.
Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
Carbon dioxide is released. Here is a diagram...
1. Contains their own DNA
2. Contains ribosomes that closely resemble prokaryotic cells
3. Reproduce by fission, and they are independent from cells.
Correct matching of invertebrates and its characteristics are as follows:
Sponges are animals which have many cell but no mouth, muscles , heart or brain. They are sessile and can not move from place to place like other animals do, filter feeding animals with an asymmetrical body plan.
Cnidarians are the animals with radial symmetry and stinging cnidocyte cells. These animals consists a special cell cnida which functions in preying catch and defense. example- jellyfish, anemone.
Flatworms are the worm like animal which do not consist a body cavity or coelom. example- fluke and tapeworms.
Roundworms or threadworms are segmented worms that can live in water or land. They consist a body cavity and internal organs. examples- pinworms and hookworms.
Mollusks are the animals which consist mentle, foot and and sometimes a shell. example- octopus, squids.
Echinoderms are the animals which have radial symmetry and an endoskeleton made out of calcareous plate. These animals live only in marine environment.These animals lack circulatory and excretory systems.
Arthopods are the animals with jointed legs and an exoskeleton made out of chitin. example- spiders, shrimps and crabs.
