<span>Mammals are advanced synapsids, animals distinguished by having extra openings in the skull behind the eyes; this opening gave the synapsids stronger jaw muscles and jaws (the jaw muscles were anchored to the skull opening) than previous animals.
Synapsids include the mammals, and their ancestors, the pelycosaurs, therapsids, and cynodonts. Pelycosaurs (like Dimetrodon and Edaphosaurus) were early synapsids, they were mammal-like reptiles. Later synapsids include the therapsids and the cynodonts (with multicusped post-canine teeth; they lived from the late Permian through the Triassic period).
The cynodonts led to the true mammals. Over time, the synapsid gait became more upright and tail length decreased</span>
Its D, im pretty sure theres not starch or acid in our DNA
The presence of vertebral column or notochord at any stage of life in any organism is the characteristic of vertebrate.
Explanation:
An animal is vertebrate if it fulfils the following criteria:
Presence of vertebral column or notochord.
Presence of endoskeleton or backbone.
The spinal cord runs above the vertebral column.
Humans embryo has notochord which becomes a vertebral column.
The alimentary canals end in the anus.
Mouth is present ta the anterior side of the vertebrate.
Have legs, fins or wings for movement.
Presence of a nervous system and sensory organs.
Presence of skin, lungs or gills.
Presence of a circulatory system.
Vertebrates include fish, amphibians, reptiles, birds and mammals.
Answer
Just think critically about why (if you were an egg laying species), having a fetus/baby develop inside of you would be advantageous.
For one, eggs are much less protected from outside factors such as predators, temperature, etc than live birthed creatures. Live birth provides protection inside the mothers body from things such as heat, cold, moisture, predatory animals, etc. An egg laying animal must keep its eggs at a perfect temperature and check to make sure no other animal has eaten them.
DNA, Chromosomes, Nucleus, Cell, Organism
Explanation:
DNA makes up the Chromosomes, which are stored in the nucleus, which is the brain of the cell, and cells make up organisms.