Answer:
Vertebral column.
Explanation:
The main division of the animal phylum includes chordates and non -chordates. Most of the chordates have bilateral symmetry, triploblastic animals with the digestive system, circulatory system and excretory system.
Chordates have some specific features that distinguishes them from the non chordates. Chordates posses notochord, dorsal hollow nerve cord, post ana.l tail and pharyngeal gill slits at the specific or the some stages of their life. The vertebral column is present only in vertebrates and not present in other chordates.
Thus, the correct answer is option (c).
Answer:
D. The cells in group B are prokaryotic because they replicate their DNA in the cytoplasm.
Explanation:
The cells of group A are prokaryotic because it is prokaryotes which do not have a double membranous structure called nucleus for storing their genetic material. The genetic material of prokaryotes is spread in the cytoplasm in the form of a circular DNA which is called as nucleoid. Since they do not have a separate organelle like nucleus for storage of their genetic material, they are bound to replicate their DNA in the cytoplasm. In contrast to prokaryotes, eukaryotes have nucleus for storage of their genetic material and in eukaryotes replication is an exclusively nuclear event.
Answer:
False.
Explanation:
"Antibiotics are drugs that kill harmful microorganisms. It attacks the normal functioning of the disease-causing."
Answer: Aids in preventing polyspermy.
Explanation:
The polyspermy is a condition in which more than one sperm penetrate the nucleus of the mother egg. This process results in the contribution of extra centriole to the egg. The presence of the extra centriole the first division is affected and chromosomal partitioning hampers.
In the given situation, the tiny channel of micropyle can accept only one sperm to fuse with the egg membrane thus this will aid in preventing the polyspermy.
An organelle is a specialized structure inside Eukaryotic cells.