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: B. Tendon
Explanation:
A tendon is a fibrous connective tissue which attaches muscle to bone. A tendon serves to move the bone or structure. Tendons may also attach muscles to structures such as the eyeball. While a ligament is a fibrous connective tissue which attaches bone to bone, and usually serves to hold structures together and keep them stable.
A bursa is a tiny fluid-filled sac that functions as a gliding surface to reduce friction between tissues of the body. The plural of bursa is bursae. There are 160 bursae in the body. The major bursae are located adjacent to the tendons near the large joints, such as the shoulders, elbows, hips, and knees.
A fascia is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches, stabilizes, encloses, and separates muscles and other internal organs. From the various definitions given above shows that the tendon is the correct answer to the question asked.
Answer: Option E) polar
Amino acid-derived and peptide hormones are unable to diffuse across a cell membrane because they are polar
Explanation:
Amino acid-derived and peptide hormones such as serotonin, epinephrine, dopamine etc, are unable to diffuse across a cell membrane because they consist of several repeating units of amino acids with positively charged or negatively charged side chains.
Thus, the side chains make these hormones water-loving (hydrophilic), and impassable to the hydrophobic layer of the cell membrane.
