Answer:
In humans, both sperms and ova contain 23 chromosomes.
Explanation:
During fertilization, the diploid chromosome number 46 is regenerated in the zygote. After 24 hours of fusion, human zygote starts to divide by mitosis, commencing the embryonic period. The zygote is divided into 2-cells, 4-cells, 8- cells and then 16-cells
Answer:
The problems that can be caused by Expansion or Contraction a;long with the solutions are:
Explanation:
- The railway tracks made of steel expand during the summer and contract during the winter. This can cause them to become curved during the summer thereby causing rail derailment.In order to prevent this, an air gap is kept in between the railway lines so that they get the space to expand without getting curved.
- The electric wires linking the telegraph posts are made up of metals and so they expand in the summer and contract in the winter, which can cause them to tear. This is why the wires are loosely fixed so that they can expand and sag in the summer and contract and tighten in the winter.
- Bridges are constructed with joints where some space is maintained to allow the easy expansion and contraction in summer and winter respectively.
Pediatrician would test the child with a simple cough
Pain is more defined as a symptom
