non-disjunction is a pathological event that occurs during the second anaphase in meiosis when sister chromatids are not separated. As a result one of the resulting cells will have 1 extra chromosome and the other will be 1 short. An example of a non-disjunction that can occur in humans is Down syndrome that has a frequency of about 1/1000 people. It is caused by the non-disjunction of the 21st pair of chromosomes.
Answer: Because it can change size based on the needs.
Explanation:
<u>The term niche defines an organism´s role in an ecosystem </u>and it also encompass what the organism eat or how it interacts with nonliving elements of the environent.
The realized niche could be regarded as flexible because it is able to change its size based on what it needs. For example, it could increases or decreases its size in competition between resources with other species since they are part of the same ecosystem.
Answer:
Eukaryotes:
-Organisms with a well defined nucleus are known as eukaryotes. such cells are called as eukaryotic cells.
- Their nucleus is enclosed within the nuclear membrane.
- They do not posses a mitochondria.
- The cell wall is the outer most layer of a eukaryotic cell (only plant cells have a cell wall)
- The cells are divided by a process called mitosis.
Eg: Plants, Animals.
Prokaryotes:
- Organisms without a well defined nucleus are known as prokaryotes. Such cells are called as Prokaryotic cells.
- They lack nuclear membrane.
- Mitochondria, Golgi bodies, chloroplast and lysosomes are absent.
- The genetic material (DNA) is present on the chromosome.
Eg: Every organism coming under the kingdom monera.
Explanation:
