Answer:
activate memory cells is lymphocytes
engulf and digest pathogens is phagocytes
and produce antibodies is lymphocytes
Explanation:
Answer: Option A
Explanation:
A tunicate is marine invertebrate animal which is a part of chordates. They have notochords and dorsal nerve chord. The subphylum of the organism is called as Urochordata.
The adult urochordates lack notochord but the larval stage of the urochordates have notochord. This is because it helps in swimming of the organism which is required only at the larval stage.
The adult stage of the tunicates is sessile and they do not swim so they do not require notochord.
<h2>Koch's Postulates.</h2>
Explanation:
The next step should be isolate the microorganism from the mice and check if it is identical to the original microbe.
According to Koch's postulates, a microbe can be considered as a causative agent of a disease only after all the following are established:
- The microorganism should be present in all the organism suffering from the disease.
- The isolated microorganism should be grown in pure culture.
- The organism grown in the culture should be reintroduced in the susceptible but healthy host.
- Finally the microorganism must be re-isolated from the experimental host an cultured to see whether it is identical to the original specific microorganism.
Answer: true
Explanation: In gel electrophoresis, the smaller the size/molecular weight of DNA the faster it moves across the gel and vise versa. This is as a result of the pore size of the gel which is usually prepared 1g of agarose in 100ml of distilled water. So a DNA fragment with 1000 base pairs will "struggle" its movement across the gel pore making it mive less faster and further. Movement and molecular weight of DNA are inversely proportional.
