As hinted in the question, the cross bridge cycle is a
series of molecular events that occur after excitation of the sarcolemma. A
cross bridge is formed when a myosin head bound to actin. The cross bridge
cycle depends on the presence of calcium ions
Both food chains and food webs contain plants and animals so it is not A.
Food chains separate by trophic level not food webs so it is not B
***Food chains show energy flow by each trophic level and food webs do not therefore it is C***
1. Muscular contractions in the intestine causing the movement of food.
2. Food that has a high fibre content.
3. A nutritional disease caused by a person refusing to eat.
4. Physical breaking down of food in the mouth by the teeth
5. Finger-like projections in the small intestine
6. The breaking down of large fat molecules into tiny droplets.
7. Process by which the liver converts excess amino acids into urea.
8. Region of the alimentary canal where most of the water is reabsorbed.
9. Muscular organ connecting the pharynx to the stomach.
10. Valve that controls the entry of food from the stomach into the duodenum,
Question:
A---enzyme A------>B----enzyme B------>C
Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with _____.
A) nutrient A only
B) nutrient B only
C) nutrient C only
D) nutrients A and C
Answer:
B) nutrient B only
Explanation:
The mutant has a mutation in the gene that codes for the enzyme A. Therefore, this mutant would not be able to convert the substance A into B. Without the presence of substance B, the final product can not be formed. However, if the mutant is supplemented with the substrate "B", it can convert the B into the final product (substance C). Therefore, the mutant would be able to grow in the medium to which the already prepared substance B has been added.