Step 1: Overview of the Sperm Structure. - The human sperm is a microscopic, motile cell with three main parts: head, middle piece, and tail.
Step 2: Describe Each Part. - Head: Contains the nucleus with the genetic material (haploid DNA). It is covered by a cap-like structure called the acrosome, which contains enzymes to penetrate the egg during fertilization. - Middle Piece: Contains mitochondria that provide energy for the sperm's movement. - Tail (Flagellum): A long whip-like structure that enables the sperm to swim towards the egg.
Final Answer: The human sperm consists of a head (with genetic material and acrosome), middle piece (with mitochondria), and a tail (for motility).
Mention the events related to the following historical dates:
\[\begin{array}{rl} \bullet & 321 \,\text{B.C.} \\ \bullet & 1829 \,\text{A.D.} \\ \bullet & 973 \,\text{A.D.} \\ \bullet & 1336 \,\text{A.D.} \\ \bullet & 1605 \,\text{A.D.} \\ \bullet & 1875 \,\text{A.D.} \\ \bullet & 1885 \,\text{A.D.} \\ \bullet & 1907 \,\text{A.D.} \\ \bullet & 1942 \,\text{A.D.} \\ \bullet & 1935 \,\text{A.D.} \end{array}\]