First of all, let us remember that "fitness" is defined as living enough to reproduce. If an organism has survived long enough to reproduce, it has done its part as far as survival is concerned, and id deemed "fit".
1) There is a struggle to survive. LIFE IS HARD. Survival is affected by limited resources, predators, and environmental factors. Organisms must compete with other organisms to obtain the necessary resources to survive. Organisms must evade predators and find successful ways to survive in challenging environments. Many more offspring are produced than those who stay alive long enough to reproduce themselves. Some offspring survive to adulthood and reproduce, many do not.
2) Traits in offspring are inherited from their parents.
3) There is variation in these inherited traits in the offspring. Most individuals among the offspring will not be identical to each other or their parents, but at the same time will carry the traits of their parents.
4) As conditions change, variations in traits may become more favorable than others for survival. Individuals who have the traits that enable them to survive and reproduce will pass these traits down to the next generation. Go back to step #1.
The phylum Echinodermata , which contains about 6000 species, gets its name from the Greek, literally meaning "spiny skin." Many echinoderms actually do have "spiny" skin, but others do not. This phylum exists exclusively in the sea, and cannot be found on land or in fresh water. All echinoderms have one thing in common: radial symmetry. This means that the creatures have appendages (or body construction) which point outward from the center of the body like the spokes on a bicycle wheel. Furthermore, these appendages usually occur in multiples of five, although there are a few exceptions. There are several well known members of this group, like sea stars and sea urchins. The radial symmetry is obvious in these creatures.
Answer:
e. Red segregated from brown in meiosis I, and straight segregated from curled in meiosis I.
Explanation:
A cross between two flies heterozygous for both genes produced an offspring with the phenotypic ratio of 9:3:3:1. This ratio is expected according to Mendel's law of independent assortment, which states that alleles of the same gene assort independently during gamete formation.
Before meiosis starts in flies, a single diploid cell duplicates its DNA, so each chromosome has 2 sister chromatids that contain the same information.
- During meiosis I, <u>the homologous chromosomes separate</u> into two daughter cells. The chromosome number is reduced by half, but each chromosome has two sister chromatids.
- During meiosis II, <u>the sister chromatids separate</u> and each daughter cell from meiosis I divides into two new daughter cells (to get the total of 4 haploid cells).
In a heterozygous fly, each homologous chromosome contains a different allele, and the sister chromatids are copies that carry the same allele. For that reason, both traits were segregated during meiosis I.
Hair and nails are part<span> of the integumentary </span>system<span>.</span>
Answer:
Transgenic organism are the genetically modified organisms on their molecular level by altering their gene to improve the particular quality that is related to the particular gene in the organisms. It can be perform in bacteria, plants and animals, the produced organisms called transgenic organisms. The beneficial applications of such organism are given as follows:
Transgenic bacteria: these bacteria are first organisms to be genetically modified and used for several functions such as human proteins, producing material plastics and many more.
Transgenic plants: such genetically modified plants can be used to enhance food quality and quantity, to make pest resistant breed and increase the extreme condition tolerance and many more.
Transgenic animals: they are used to improve the quality of food supply, improve medicines and research purposes and many more applications.
