Answer:
Oxygen
Explanation:
Oxygen is the by product of photolysis during photosynthesis whereby water molecules are split to form protons (H+ ions), electrons and oxygen (by product).
Oxygen is not needed during any of the reactions in photosynthesis and Calvin cycle and will not affect the rate of photosynthesis or possibility of photosynthesis occurring. However, it will affect the process of aerobic respiration instead.
Carbon dioxide is needed in carbon fixation during the Calvin cycle. Without it, 6 carbon sugars cannot be formed.
Water is needed for photolysis to produce protons (maintain the electrochemical gradient) and electrons (to replenish lost electrons)
Chlorophyll are pigments that harvest light energy to excite electrons produced from photolysis of water to be passed down the electron transport chain.
Light is needed as a source of energy to energise the electrons
Pancreas is an endocrine gland . It secretes lipase as well. lipase breaks down fats into glycerol by the process of emulsification. it secretes hormones insulin and glucagon
The correct answer is A.
The use of antibacterial drugs can cause modifications in the genetic material of the concerned bacteria. If the genetic material of the bacteria are modify, that means they have undergone mutation. Because the base sequence of the normal and that of the mutated gene is different, antibiotic will not be able to recognize the bacteria again and thus will not be able to attack it.
Answer:
The correct answer is D) short-lived plasma cells that secrete antibodies for the antigen
Explanation:
Each B lymphocyte has an antigen receptor (BCR: B cell receptor), a surface immunoglobulin (IgM or IgD), that binds to specific domains of the antigen called antigenic determinants or epitopes. Only B lymphocytes with a high antibody affinity for the antigen, and which are capable of processing and presenting it, will be positively selected. In this contact between the two cells, an exchange of chemical signals takes place that leads to the activation, clonal proliferation and differentiation of B cells into two sister subclones: one of antibody-secreting plasma cells, and the other of memory primed B cells. Therefore, only these last positively selected B lymphocytes will survive, proliferate and differentiate into plasma cells, synthesizing and secreting antibodies of a single isotypic class, with a unique specificity and high affinity, improving the ability to adhere to the antigen and, thus , neutralize and destroy pathogens.
