Answer:
by the sarcoplasmic reticulum's calcium ion pumps
Explanation:
Rigor mortis or postmortem rigidity, is a state caused by chemical changes in the muscles that occur post mortem and cause the limbs of the corpse to stiffen.
This occurs because after death, there is no cellular respiration and consequently, no oxygen nor ATP (ATP is required for the muscle relaxation).
Calcium enters the cytosol after death because it is released due to the deterioration of the sarcoplasmic reticulum and due to the breakdown of the sarcolemma. Ca2+ ions activate the formation of actin-myosin cross-bridging necessary for the contraction. Muscles are unable to relax, because myosin heads continue to bind with the active sites of actin and there is no ATP to destabilize the myosin-actin bond.
Answer:
a. 1/2 b. The organism is an animal
Explanation:
a. What is the medullary index for an organism that has a medulla width of 2cm and hair shaft width 4cm?
Medullary index = diameter of medulla/diameter of hair.
Given that diameter of medulla = medulla width = 2cm and diameter of hair = hair shaft width = 4cm,
Medullary index = diameter of medulla/diameter of hair = 2 cm/4cm = 1/2
b. Is this organism human or animal?
Since the medullary index = 1/2 > 1/3 (if it is ≤ 1/3 it is human hair and ≥ 1/2 it is animal hair), it is animal hair. So, the organism is an animal.
The mouth is the beginning of the digestive tract; and, in fact, digestive starts here when taking the first bite of food
Both the temperature and the pressure increase.
Answer: d ribosomes
Explanation: Ribosomes help make protein which helps make enzymes
