Asexual: Offspring arise from single organism
Sexual: Genetic information from two organisms (male and female), where one produces a motile gamete (male) that travels to fuse with a larger stationary gamete produced by other (female).
Internal Fertilization: Union of an egg cell with a sperm during sexual reproduction inside the body of a parent.
External Fertilization: The sperm cell reunites with the egg cell in the open, rather than inside the body of a parent.
:) I'm sure you can figure it out from the information I stated above
Answer:
The correct answer is option B ( ligand gated channels opened by neurotransmitter molecules).
Explanation:
Input region or postsynaptic region or dendrite is the site of neuron cell which receives the impulse from the pre-synaptic neuron at the synaptic junction.
The cell membrane of the dendrite is embedded with ligand-gated channels which opens up in response to the ligand (neurotransmitters) produced by the neurotransmitter vesicle of axon or output region of neuron.
The neuromuscular junction is such a case where acetylcholine receptors present in the dendrite opens in the presence of acetylcholine.
Thus, option B ( ligand-gated channels opened by neurotransmitter molecules) is the correct option.
Answer:
The nucleic acid is a macromolecule present in living systems in the form of either DNA or RNA, whose molecule consists of many nucleotides which are linked with each other to form long chains. The presence of DNA or RNA in an individual promotes continuity of life. The variability and complexity of nucleic acid are dependent on its constituent molecules as, sugar, a phosphate group, and a nitrogenous base. However, two monocyclic nitrogenous bases were classified purines (adenine:A, guanine:G) and pyrimidines (thymine:T, cytosine:C, and uracil:U).
In addition, RNA is a single-stranded structure which differs from DNA in two aspects, the sugar content of RNA is ribose, and pyrimidine base uracil replaces the thymine base of DNA. A ratio between two strands of DNA can be calculated by using Chargrff's rule which states that "DNA from any cell of all organisms possess a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases'.
The purine to pyrimidine ratio in RNA with different bases is given below in the following table:
Presence of single strand in RNA does not follow chargaff's rule and alters the purine: pyrimidine ratio. The above ratio of each base in the given information is not equal, due to which the ratio of purines to pyrimidines is different. The ratio of DNA and RNA is not equal because DNA has its complementary DNA strand. However, bases in RNA might vary due to its single-strandedness property, but its ratio is dependent on the species.
Therefore, it can be concluded that the ratio of purines to pyrimidines is dependent on the species due to its genetic makeup. Hence, option (c) is correct.
The choice that best fits and answers the question is;
D: absorption
I hope this answer is sufficient and has aided you.
Cheers.