A fertilized egg is called a zygote until it divides into 16 cells, forming a ball-shaped structure called a morula. ... In humans, it takes about four days for a zygote to become a morula and another three days until the embryo attaches itself to the mother's uterine wall.
Answer:
Domain
Explanation:
It is common to find in textbooks the classification of living organisms into five kingdoms: Kingdom Monera, Kingdom Protista, Kingdom Fungi, Kingdom Plantae and Kingdom Animalia. It is now known that this classification has some serious flaws and that some kingdoms are no longer considered.
A widely accepted classification today is one that comprises one category above the kingdoms: domains. This classification was proposed by Carl Woese in 1977 and is based on molecular phylogeny data. According to Woese, there are three domains: Archaea Domain, Bacteria Domain, and Eukarya Domain.
1) They provide ecologically and economically indispensable goods.
2) They provide nesting and feeding habitats for aquatic plants and animals.
3) They maintain healthy ocean environments
4) They remove pollutants from rivers and streams
Answer:
fixation
Nitrogen is converted from atmospheric nitrogen (N2) into usable forms, such as NO2-, in a process known as fixation. The majority of nitrogen is fixed by bacteria, most of which are symbiotic with plants. Recently fixed ammonia is then converted to biologically useful forms by specialized bacteria
Explanation:
