Answer:
The beginning of Cambrian period was about 541 million years ago and ends about 484.5 million years ago.
Explanation:
Cambrian period is a geographical period that appears in Paleozoic Era and lasts at Phanerozoic Eon to the beginning of Ordovician Period and the name was given as most of the sedimentary deposits were found at that period The majority of living organism includes unicellular or some multi cellular complex life forms.
Most live forms were aquatic and arthropods were the most dominant animals in the water that are known by studying the fossil records.The species adapt themselves to change with the environmental variations.
Animals like <em>Protichnites</em> and <em>Climactichnites</em> were found during this period.
The fossil records also suggested the presence of euthycarcinoides that are the extinct arthropod species.
Answer:
I believe the answer is A
Explanation:
I think it is A because the original function of the spinal cord is to complex organization of nerve cells responsible for movement and sensation. It carries signals between the brain and the rest of the body.
What is Mitosis?
"Mitosis is the cycle that eukaryotic cells go through in order to divide. During mitosis, a cell duplicates its DNA and divides into two genetically identical cells.
Mitosis and cytokinesis are part of the mitotic phase of the cell cycle, which make up about 20 percent of the entire lifecycle of a cell. The end result of mitosis is two completely separate cells with equal and similar cellular components. "
"Meiosis is the special cell division cycle for gamete cells, or sex cells. Chromosomes carry the genetic code for an organism, and come in pairs. In asexual reproduction, a cell will just divide itself to create two new cells. In sexual reproduction, the parent provides one set of each chromosome, or half the genetic code for an organism. When the two parent donor gametes – typically an egg and sperm – meet in fertilization, they provide the offspring with the full set of necessary chromosomes. For example, humans require 46 chromosomes, or 23 pairs. An egg or sperm will have just 23 chromosomes, or one half of the pair. This makes gamete cell division more complex than ordinary cell division. Within this cycle, the number of chromosomes is halved, typically going from a diploid (two sets) to haploid (one set) cell. It also includes a step where the chromosomes cross, allowing for more genetic diversity in reproduction."
- https://blog.udemy.com/meiosis-vs-mitosis/ = This info was from this site
Hopefully that helped, have a wonderful day :)
Yes, short answer, I can not give you the specifics (consult your biology textbook)
Honestly this subject is really really hard .. I wish I could help sorry
