Answer:
The cell wall present in fungi and bacteria permits these cells to withstand very dilute external medium without bursting.
Explanation:
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages
The complete question is :
The success of plants extending their range northward following glacial retreat is best determined by _____.
A) whether there is simultaneous migration of herbivores
B) their tolerance to shade
C) their seed dispersal rate
D) their size
Answer: The seed dispersal rate
Explanation:
The seed dispersal can be defined as the movement of the seeds away from the parent plant. The ability of the plant to extend is completely dependent on the ability of the plant to disperse its seeds.
Plants have very limited ability, they need vectors to carry its seed from one place to another.
The biotic and abiotic vector both are involved in carrying the seeds which helps in expansion of the trees.
hence, the correct answer is option C
The question is incomplete. The complete question is:
Question: Why do organisms without oxygen need to convert pyruvate to lactate?
A) because pyruvate is toxic to the cells
B) in order to regenerate NAD+
C) in order to use lactate in the citric acid cycle
D) because lactate is needed to produce ATP
Answer:
B) in order to regenerate NAD+
Explanation:
Kreb's cycle and electron transport chain (ETC) are the aerobic stages of cellular respiration. ETC regenerates NAD+ and FAD+ by oxidation of NADH and FADH2 produced during glycolysis and Kreb's cycle. Here, oxygen serves as the terminal electron acceptor.
Glycolytic reactions use NAD+ as an electron acceptor and produce NADH. Therefore, a constant supply of NAD+ is required to sustain glycolysis. In absence of oxygen, ETC cannot occur and organisms convert pyruvate into lactate. Pyruvate is reduced in lactate and NADH serves as the electron donor. Thereby, lactate fermentation regenerates NAD+ to continue the process of glycolysis.
Yes humans do have the obligations of preserving the habitats of chimpanzee as it is considered as an endangered species. Most of the human practices such as tree logging, environment pollution, exploitation of animals and others has led to many species being endangered to extinction.
