Answer:
algae
Explanation:
thousands of microbes including bacteria and phytoplankton are interacting to form the base of the food web of the entire ocean. algae are phytoplankton that takes in sunlight, nutrients, carbon dioxide, and water to produce oxygen and food for other organisms.
Answer:
Prions causes abnormal folding of the prion proteins in the brain.
Explanation:
Prions are the abnormal infectious agents composed only of the proteins and no nucleic acids. The prions cause several neurodegenerative diseases in the humans as well as the mammals.
The prions cause the cow mad disease in the cows by affecting the brain of the cow as the prions act on the prion proteins present in the brain only and change their conformation. This leads to the degeneration of the neurons and causes tiny pores in the brain giving sponge-like appearance.
This slows down the mental activity and thus ultimately leads to the death of the cow.
Answer:
The correct answer is A. The larynx moves up against epiglottis when food is swallowed to prevent passage of food into it.
Explanation:
The epiglottis is a moist, cartilaginous structure that is part of the cartilaginous skeleton of the larynx. It also marks the boundary between the oropharynx and the laryngopharynx. The epiglottis obstructs the passage of the bolus at the time of swallowing preventing it from going to the respiratory system.
Larynx closure occurs when the vestibular and vocal folds approach the midline during swallowing. Occasionally, when you eat very fast, solid foods or liquids can enter the larynx.
A) DNA fulfils all three conditions:
<span>(1) copy itself precisely - in the process of replication, DNA copies itself and two molecules of DNA are formed. This process is very precise thanks to the great number of proteins involved in these process that prevents error occurring and proteins that can fix the error if it occurs.
(2) be stable but able to be changed - DNA is very stable molecule otherwise, it cannot be a genetic material. However, its chains can separate in a short length so the translational machinery can attach to it and the process of transcription can occur. Also, in crossing over, during meiosis, </span>the exchange of genetic material occurs and chromosomes change a bit.<span>
(3) be complex enough to determine the organism’s phenotype - it contains a number of genes responsible for different traits. All of this results in the </span>organism’s phenotype.
B) DNA copies itself. <span>Meselson and Stahl conducted the experiments on DNA replication in which they used </span>E. coli<span> bacteria as a model system. After they labelled all bacteria's DNA with heavy 15N by using medium with heavy 15N, they switched bacteria to medium with light 14N. After several generations, all bacteria's DNA was labelled with light 14N. This experiment evidenced that the self-replication of DNA is semi-conservative process.</span>
Answer:
The correct answer is - true.
Explanation:
In the meiosis cell division, there are four cells present with n number of chromosomes which means these cells generated from by the meiosis have a half number of the chromosome as their parents. This is the reason this type of cell division is known as a reduction division.
These cells that are produced are sex cells or reproductive cell sperm in male and egg in female all have n number of chromosome number as they have to fuse to form a zygote.
