Cell wall is the outer permeable covering in all pants and almost all prokaryotes ! cell wall are mainly made up of cellulose , sometime by chitin!!
A first-hand source such as an experiment is called a primary source.
A primary source is where you can share new information or report on what you have discovered. Some primary sources are research data, interviews, audio recordings, and autobiographies.
A secondary source is where you describe and discuss about the primary sources. They are used to collect and gather primary source information. Some secondary sources are textbooks, review articles, and scholarly books.
A tertiary source is a source about summaries. A tertiary source can be used to look up information or get an overview about what it is you are wanting to know. Some tertiary sources are dictionaries, handbooks, encyclopedias, Wikipedia, and guidebooks.
The first scientific discovery is the epigenetic variation where it describes the deviation in the chemical tags that attach to DNA which affect how genes are read. Theses tags are called epigenetic markings that act as switches that control how genes can be read. Another essential discovery on human variation is the genetic variability, which measures the tendency of individual genotypes in a population to become different from one another. In addition, the variability of a trait is how much that characteristic tends to vary in response to environmental and hereditary influences.
Vestigal organs are organs that, as we evolve, the organs loose their purpose and have no function anymore. The appendix is a vestigal organ
Hope this helps
Answer:
C) extra chromosome; nondisjunction
Explanation:
