CHROMOSOMES
species
A dichotomous key is a special document that allows the reader to 'key out' an organism to some level, sometimes species, sometimes a level above species. Basically a key is a series of double statements. Each double statement has only one possible right answer; either the organism has some trait, or it doesn't. Depending on the answer, you are then taken to the next level of statements, each pair of statements whittles down the possible number of species that your organism could possibly be, and eventually lands you on the species, or genus that your organism is in.
The chromosome number is specific for each type of organism. The exact chromosome number must be maintained for the species to continue. This means that as cells reproduce, the new cells must have the same number of chromosomes as did the original cells
If in a given species, every organism survived to adulthood and then had exactly the same number of offspring as every other organism in that species, there would be a few interesting consequences. Given the universal survival and reproductive success, that species would experience a population explosion. Eventually, this would have to produce general starvation, since food supplies cannot expand indefinitely. Also, the process of evolution would come to a stop, for that species. If everybody survives and reproduces to the same extent, then the concept of survival of the fittest does not apply, since everybody survives and everybody is equally fit.
Number of different species
Species
species
The classification of species.
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A karyotype is the number and appearance of chromosomes in a nucleus. The term is also used to refer to the complete set of chromosomes in a species.
Distribution The region where an organism is found Abundance The number of individuals in an area The density
Since a karyotype is a picture of the entire organism's chromosomes and since all species have a different number of chromosomes it makes it easy to figure out what species you are looking at just by looking at the karyotype.
A dichotomous key is a special document that allows the reader to 'key out' an organism to some level, sometimes species, sometimes a level above species. Basically a key is a series of double statements. Each double statement has only one possible right answer; either the organism has some trait, or it doesn't. Depending on the answer, you are then taken to the next level of statements, each pair of statements whittles down the possible number of species that your organism could possibly be, and eventually lands you on the species, or genus that your organism is in.
Genetics
The chromosome number is specific for each type of organism. The exact chromosome number must be maintained for the species to continue. This means that as cells reproduce, the new cells must have the same number of chromosomes as did the original cells
Any large number of some type of living organism is called a specie. They tend to stay together in a group. Examples: humans.
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