Answer:
<u><em>The correct option is C) Prions</em></u>
Explanation:
Bovine spongiform encephalopathy (BSE) or Mad Cow Disease is a disease which occurs due to transmissible particles known as prions. Prions cannot be considered as living organisms as they do not acquire many of the living characteristics. They are just considered as a protein which gest converted into an activated, toxic form as soon as they encounter a host cell. This toxic protein harms the central nervous system (CNS) of the cow host and is transmissible.
Well, when chromosomes cross over during prophase 1 of meiosis, the homologous pair of chromosomes exchange segments of DNA which happen to be the genes. So the significance of crossing-over during prophase 1 is that it adds genetic variation to sexually reproducing organisms.
Answer:
The correct answer would be calcium ion and cAMP.
Secondary messengers refers to the intracellular signaling molecules which pass the signals from the receptors located on the surface of the cell to the target molecule present within the cell.
The secondary messengers can be classified into three major class:
- Cyclic nucleotide for example cAMP (cyclic adenosine monophosphate), cGMP (cyclic guanosine monophosphate)
- DAG (diacylglycerol) and IP₃ (inositol triphosphate)
- Calcium ions (Ca⁺⁺)
Hence, from the given options, calcium ion and cAMP would make the correct choice.
Prokaryotes have no cell nucleus and no membrane enclosed organelles. Prokaryotic DNA can be found in a coiled loop floating in the cytoplasm in a region called the nucleoid (meaning nucleus-like). In other words, the nucleoid is the area in a prokaryotic cell where DNA is located.
In eukaryotic cells, DNA is located in the nucleus, the mitochondria and the chloroplasts (occuring only in plants and some protists). The nucleus contains most DNA. It is present in this compartment in the form of linear chromosomes that together constitute the genome.
Answer:
Is to supply energy for their metabolic activities
Explanation:
