Answer:
1.) stromatolites
2.) photosynthesis
3.) Ordovician
4.) Cambrian
5.) oxygen
6.) As Earth cooled, carbon dioxide dissolved in the early ocean. Cyanobacteria consumed carbon dioxide and converted it to oxygen. Methane was removed from the atmosphere as oxygen was produced, eventually leading to the Cambrian Explosion.
7.) Metabolic processes that use oxygen produce more energy than anaerobic metabolism. Simple diffusion of oxygen would limit the size of a multicellular eukaryote, but animals evolved ways to transport oxygen to their tissues, which permitted an increase in size.
Explanation:
From Penn
Answer:
Option-B
Explanation:
Schleiden was a German botanist and Schwann was a German zoologist who independently observed that plants and animals are made of cells.
Once when they together met in a conference, they shared what they observed and later both reached the conclusion that cell is the functional and structural unit of living organisms.
In the given question, since Schwann was a zoologist, therefore, he concluded that the cell in an organism must function properly whereas Schleiden was a botanist and concluded that the different structures of a plant are composed of cells.
Thus, Option-B is the correct answer.
Answer: humoral immune response
The main antibody isotypes in the influenza-specific humoral immune response are IgA, IgM and IgG. Mucosal or secretory IgA antibodies are produced locally and transported along the mucus of the respiratory tract by transepithelial transport and can afford local protection from infection of airway epithelial cells.
Answer:
A dorsal root (sensory or afferent) and a ventral root (motor or efferent) originate from the medulla. They unite near the intervertebral foramen, forming the spinal nerve. The nerves emerge from the intervertebral foramen, dividing into ventral and dorsal ramus.
Explanation:
The nerve is a set of nerve fibers perceptible to the naked eye and wrapped in connective tissue. They are made up of roots, trunks and nerve branches (some of them come together and form plexuses).The spinal nerve originate from the spinal cord in the form of 31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. They emerge from the spinal cord through two roots: dorsal roots, made up of sensory fibers that come from the sensory neurons of the spinal ganglion and that penetrate the spinal cord through the posterolateral and ventral root, made up of motor fibers, coming from the motor neurons of the anterior horn and visceral of the lateral horn of the gray matter of the spinal cord. This root exits the spinal cord through the anterolateral groove, then joins the posterior root to form the spinal nerve, which exits the vertebral canal through the corresponding intervertebral foramen.Each spinal nerve, after leaving the vertebral canal, emits two primary ramus: the dorsal ramus, contains somatic and visceral fibers that go to the skin and muscles of the back and the ventral ramus, which supplies the ventrolateral surface of the skin, body wall and extremities.
Animals can be classified into two main groups:vertebrates and invertebrates<span>. The main difference between </span>vertebrates and invertebrates<span> is that</span>invertebrates<span>, like insects and flatworms, </span>do<span> not</span>have<span> a backbone or a spinal column. Examples of</span>vertebrates<span> include humans, birds, and snakes. hope this helped</span>
