Hello there.
<span>The crossing over is a process where the chromatids pair and exchange sections of DNA, which lead to exchange genes (this result is call genetic recombination). So, the crossing over between nonsister chromatids during meiosis is significant in heredity because it leads to an increase of genetic variation (answer d.)</span>
The limb buds appears in the in the fourth week of gestation and the
upper limb is visible on day 24. Initial elongation of the bud forms around 33
days and continues to elongate until seven weeks.
Answer:
Three primary components of axial skeleton are skull, vertebral column and ribs.
Explanation:
Axial skeleton forms the central axis f the body. Three primary component of axial skeleton are:
Skull: Skull protects the brain and supports the face structure. Twenty two bones are present in the skull. Two main categories of skull bone are cranial bone and facial bone.
Vertebral column: Vertebral columns support and protects the spinal cord. The vertebral column serves as the attachment site for the muscles and neck.
Ribs cage: Ribs cage is also known as thoracic cage and includes the structure of sternum, ribs, coastal cartilage and thoracic cartilage. Ribs consists of twelve bones.
