<span>The geologic time scale is divided into periods, which are then divided into epochs, which are further divided into ages. For example, the time of the dinosaurs lasted 3 periods (Triassic, Jurassic, Cretaceous), each period had 3 epochs (late, early, middle), and each age fit into one of those. Many epochs have more than 1 age associated with them.
As for the basis for differentiating the eras, I'm not so sure. The only one I can say for sure is the end of the Cretaceous, which is when the dinosaurs suddenly became extinct due to a meteor impact. I think the divisions are based on significant, global-scale events that changed the world.
Sorry its so long but that the answer i think >:) ur welcome
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Answer:
1) All living things are made up of cells.
2) Cells are the building blocks/smallest unit of life.
3) All cells come from preexisting cells (cell division).
Explanation:
Answer:
Three different kinds of muscles are -:
- <u>SKELETAL MUSCELES </u>
- <u>CARDIAC MUSCLES </u>
- <u>SMOOTH MUSCLES</u>
Explanation:
- <u>SKELETAL MUSCLES -: </u>There are long, cylindrical, and striated skeletal muscle cells. They are multi-nucleated, which means they have more than one nucleus. This is because from the fusion of embryonic myoblasts, they are created. Each nucleus controls the sarcoplasm's metabolic demands around it. There are high energy requirements for skeletal muscle cells, because they contain several mitochondria in order to generate adequate ATP. <u>Examples of skeletal muscles: arms and legs- </u>T<u>he muscles that belong to the arms and legs feature in pairs. Abdomen and Back- These muscles are connected to the various sets of skeletal muscles that run across the torso.</u>
- <u>CARDIAC MUSCLES -</u>: Cardiomyocytes have a short and narrow outline and are fairly rectangular. They are about 0.02 mm wide and 0.1 mm (millimetres) long, respectively. There are many sarcosomes in cardiomyocytes, which provide the required energy for contraction. Cardiomyocytes usually contain a single nucleus, unlike skeletal muscle cells. Cardiomyocytes, although they contain more sarcosomes, normally contain the same cell organelles as skeletal muscle cells.<u> example - cardiac muscle is present in heart. </u>
- <u>SMOOTH MUSCLES -:</u> Smooth muscle cells have a single central nucleus and are spindle-shaped. They range in length from 10 to 600 μm (micrometers), and are the tiniest type of muscle cell. In the expansion of organs like the kidneys , lungs, and vagina, they are elastic and therefore essential. As in cardiac and skeletal muscle, the myofibrils of smooth muscle cells are not aligned, meaning they are not striated, hence the term smooth. <u>example of smooth muscles -: Walls of blood vessels , Walls of stomach ,
Ureters , Intestines , In the aorta (tunica media layer), Iris of the eye. ,Prostate and Gastrointestinal Tract.</u>
Lyases
Lyases are class of enzymes that catalyzes reactions involving the formation of double bonds.
Lyases are class of enzymes that catalyzes the joining of C-C ( carbon to carbon), C-O (carbon to oxygen), and C-N (carbon to nitrogen) bonds by hydrolysis or oxidation. These bonds are usually held by the process of elimination which leads to the formation of new double bonds or cyclical molecules. Examples of lyases include; aldolase and adenylate cyclase.
