Big Idea #3

Big Idea 3

2. Diploid

This feather of a bird comes from an animal that has a diploid set of chromosomes in somatic cells. This means that the bird has 2 of each chromosome because its somatic cells go through mitosis rather than meiosis . Mitosis is cell division in which the daughter cells are diploid, rather than haploid, as in meiosis.

4. Eukaryote

This deer near at the Folsom zoo is an example of a eukaryote. A eukaryote is any organism whose cells contain membrane-bound organelles and a nucleus. These organisms are much more complex than prokaryotes, who lack a nucleus. Eukaryotes go through meiosis and mitosis for cell division.

6. Gamete

This magnificent peacock is a result of gametes. A gamete is a sex cell. The male gametes are called sperm, and the female gamete are eggs. Sperm fertilize eggs in order to sexually reproduce. Gametes are haploid, meaning they only have one set of chromosomes.

7. Haploid

This plant's cells are haploid: they only have one set of chromosomes. This is a result of alternation of generations, which is a cycle used by plants to increase genetic diversity. One generation of the plant will be a sporophyte (diploid), while the next will be a gametophyte (haploid).

9. Flock

This group of seagulls on the American River are called a flock. A flock is a group of birds that flies and forages together. The flock pictured is resting on the river and hunting for fish. It is very similar to a herd of mammals. Advantages to living in a flock include safety through numbers and a better chance of finding food. A major disadvantage is the reduced feeding efficiency caused by greater numbers.

10. Behavior
An animal's behavior is defined as its reaction to outside stimuli. This ostrich is investigating something on the ground. That something is the stimuli in this case.

16. Mitosis

This sleeping black bear's somatic cells undergo use mitosis for cell division. Mitosis is the process of cell division that results in two diploid daughter cells. In mitosis, the cell divides only once, during the stages of prophase, metaphase, anaphase, and telophase. It breaks apart sister chromatids. Mitosis enables the growth of multicellular organisms, and also produces cells for tissue repair.

17. Meiosis

These plants undergo meiosis as part of their alternation of generations. Meisois is a form of cell division that results in four haploid daughter cells.There are two cell divisions, the first of which divides homologous chromosomes, and the second divides sister chromatids. Meiosis is used to produce gametes and to increase genetic variability.

18. Phenotype

This red fox from the Folsom Zoo is an example of a species with multiple phenotypes. A phenotype is an observable trait of an organism. In this case, the phenotype is the color of the fox's fur. The fox is able to have different shades of red, gray, and silver as the color of its fur. Phenotypes are a result of the dominant allele of the organism's genotype. For example, the organism does not have to be homozygous dominant for the dominant phenotype to appear. It can also be heterozygous.

22.Tropism

Tropism is whenever a biological organism (usually a plant) moves because it is affected by outside stimuli in the environment. An example is this tree, which is shown growing out of an area shaded by a larger tree and towards the available light. This is called heliotropism. It is also reasonable to guess that it is affected by hydrotropism (affected by water) as it is moving towards the lake. Other examples of tropism include thermotropism (affected by temperature), geotropism (affected by gravity), and chemotropism (affected by chemicals)