The correct answer is a dichotomous key. Basically, you use the key to decide what species an organism is by looking at what traits it has, and if it doesn't have some traits you can instantly rule out a large number of species which brings you closer to your answer of what the species is that you're looking at.
Cell division is the process by which a parent cell divides into two or more daughter cells.[1]Cell division usually occurs as part of a larger cell cycle. In eukaryotes, there are two distinct types of cell division: a vegetative division, whereby each daughter cell is genetically identical to the parent cell (mitosis),[2] and a reproductive cell division, whereby the number of chromosomes in the daughter cells is reduced by half to produce haploid gametes(meiosis). Meiosis results in four haploid daughter cells by undergoing one round of DNA replication followed by two divisions. Homologous chromosomes are separated in the first division, and sister chromatids are separated in the second division. Both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle. Both are believed to be present in the last eukaryotic common ancestor.
Prokaryotes (bacteria) undergo a vegetative cell division known as binary fission, where their genetic material is segregated equally into two daughter cells. All cell divisions, regardless of organism, are preceded by a single round of DNA replication.
For simple unicellular microorganisms such as the amoeba, one cell division is equivalent to reproduction – an entire new organism is created. On a larger scale, mitotic cell division can create progeny from multicellular organisms, such as plants that grow from cuttings. Mitotic cell division enables sexually reproducing organisms to develop from the one-celled zygote, which itself was produced by meiotic cell division from gametes. After growth, cell division by mitosis allows for continual construction and repair of the organism.[3] The human body experiences about 10 quadrillion cell divisions in a lifetime.[4]
The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information that is stored in chromosomes must be replicated, and the duplicated genome must be separated cleanly between cells.[5] A great deal of cellular infrastructure is involved in keeping genomic information consistent between generations.
Answer:
Mutations are permanent changes in the DNA due to changes in nucleotide sequences. Mutations that cause addition of extra nucleotides in a nucleotide sequences are known as frameshift mutations
Answer:
This shows the interaction between the earth and sun.
Explanation:
- There is a variation in the amount of heat that reaches the different latitudes as the interaction between the sun and earth which firms different angles of incidence on the surface.
- The rays of the sun are more concentrated in mid latitudes that is the tropics and are slanting towards the poles this due the tilt in axis of earth.
- This variation lads the warm air to rise and reach the poles and similar the cold polar air reaches the tropics and develops a cycle of convective cells. This leads to a latitudinal balance in temperatures.
If there was not a constant Input of energy into the ecosystem then nothing would have the power to do anything and nothing would be alive. the energy starts with the sun, then goes to plants, then animals that eat the plants, and then the animals that eat those animals, Ect. if this chain reaction did not happen then the plants wouldn't have to power to go through photosynthesis and then we would get no energy. the amount of energy lessen with every chain that it goes through, this is why we get more energy eating plants and why they are healthier.
