Alexander Grahm Bell 5

2008-02-20T07:25:00.000-08:00

True Breeding- organisms that produce offspring identical to themselves if allowed to self pollinate.

Trait- specific characteristic that varies from one individual to another.

Hybrid- offspring of crosses between parents with different traits.

Genetics- scientific study of heredity.

Gene- sequence of DNA that codes for a protein and thus determines a trait.

Allele- one of a number of different kinds of a gene.

Segregation- separation of alleles during gamete formation.

Gamete- specialized cell involved in sexual reproduction.

Probability- likelihood that a particular event will occur.

Punnett square- diagram showing the gene combinations that might result from a genetic cross.

Homozygous- organism that has two identical alleles for a particular trait.

Heterozygous- organism that has two different alleles for the same trait.

Phenotype- physical characteristics of an organism.

Genotype- genetic makeup of an organism.

Homologous- chromosomes that each have a corresponding chromosome from the opposite sex parent.

Diploid- cell that contains both sets of homologous chromosomes.

Haploid- cell that contains only a single set of chromosomes.

Meiosis- process where the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.

Tetrad- structure containing 4 chromatids that forms during meiosis.

Crossing-over- homologous chromosomes exchange portions of their chromatids during meiosis.

Gene Map- diagram showing the relative locations of each known gene on a chromosome

2008-01-10T10:57:00.000-08:00

P. 257

1. The rate at which marierals enter and leave the cell through the cell membrane depends on the:
- Volume

2. The process of cell division results in:
- Two daughter cells

3. Pairs of identical chromatids are attached to each other at an area called the:
- Centromere

4. If a cell has 12 chromosomes, how many chromosomes will each of its daughter cells have after mitosis?
- 6

5. At the beginning of cell division, a chromosome constists of two:
- Chromatids

6. The phase of mitosis during which chromosomes become visible and the centrioles seperate is:
- Prophase

7. Metaphase is best illustrated in which figure?
- Image B

8. The timing of the cell cylce in eukaryotic cells is controlled by a group of closly related proteins known as:
- Cyclins

9. In the cell, the external regulators direct cells to:
- Speed up or slow down

10. Uncontrolled cell division occurs in:
- Cancer

10-3 Questions

2008-01-09T07:28:00.000-08:00

P. 252

1. What chemicals regulate the cell cycle? How do they work?
- Cyclins regulate the timimg of the cell cycle.

2. What happens when cells do not respond to the signals that normally regulate their growth?
- Cancer cells do not respond and they form masses of tumors that can damage the surrounding tissues.

3. How do cells respond to contact with other cells?
- The could disrupt normal activities if cancer cells mix in.

4. Why can cancer be considered a disease of the cell cycle?
- The control over the cell cycle is broken down, they don't respond to external regulators, and some stop producing internal regulators.

5. Write a hypothesis about what you would think if cyclin were injected nto a cell that was in mitosis.
- If cyclin were to be injected into a cell already in mitosis, then the cell will be caused to over regulate and cause a disruption to mitosis.

10-2 Questions

2008-01-09T07:12:00.000-08:00

P. 249

1. Name the main events of the cell cycle
- The main events are, a cell grows, prepares for division, divides to form two daughter cells, then begins all over again.

2. Describe what happens in each of the four phases of the cell cycle
- Prophase: Chromosomes become visible and centrioles move to oppsite sides of the nucleus.
- metaphase: Chromosomes line up across centerof the cell and microtubles connect the and centromere of each chromsome to the spindle.
- Anaphase: Centromeres separate and the sister chromatids separate and become individual chromosomes.
- Telophase: Chromosomes diperse into a tangle of material and a nuclear envelope re-forms around each cluster of chromosomes.

3. Describe what happens during interphase.
- The life of a cell as one cell division after another seperated by and in between period of growth.

4. What are chromosomes made of?
- They are made of two sister pair chromatids attached to an area called the centromere.

5. How do prokaryote cells divide?
- Just a simple dividing the cell into two parts.

6. How is cytokinesis in plant cells similar to cytokinesis in animal cells? How is it different?
- In an animal, the cell membrane moves inward until it pinches the cytoplasm off and in animal cells a cell plate is formed in the middle.

10-1 Questions

2008-01-09T06:51:00.000-08:00

P. 243

1. Give two reasons why cells divide.
- Cells divide because of cell growth and DNA overload in the cell

2. How is a cells DNA like the books in a library?
- Once more cells are made, they will have to wait longer to get increasing needs for a growing cell.

3. What is the solution to the problems if cell growth?
- The solution is cell division.

4. As a cell increases in size, which icreases more rapidly, its surface area or volume?
- The cell's volume

5. Calculate the surface area, volume, and ratio of surface area volume of an imaginary cubic cell with a length of 4 cm.
- Surface area: 4 x 4 x 6 = 92, Volume: 4 x 4 x 4 = 64, Ratio: 92/64 or 23/16

2008-01-07T20:40:00.000-08:00

Cell division- The process by which a cell divides to form two daughter cells. Upon completion of the process, each daughter cell contains the same genetic material as the original cell and roughly half of its cytoplasm.

chromatid- Either of the two daughter strands of a replicated chromosome that are joined by a single centromere and separate during cell division to become individual chromosomes.

centromere- a specialized structure on the chromosome, appearing during cell division as the constricted central region where the two chromatids are held together and form an X shape.

Interphase- the period of the cell cycle during which the nucleus is not undergoing division, typically occurring between mitotic or meiotic divisions. Also called Interkinesis.

Cell cycle- the cycle of growth and asexual reproduction of a cell, consisting of interphase followed in actively dividing cells by prophase, metaphase, anaphase, and telophase.

Mitosis- the usual method of cell division, characterized typically by the resolving of the chromatin of the nucleus into a threadlike form, which condenses into chromosomes, each of which separates longitudinally into two parts, one part of each chromosome being retained in each of two new cells resulting from the original cell.

Prophase- the first stage of mitosis or meiosis in eukaryotic cell division, during which the nuclear envelope breaks down and strands of chromatin form into chromosomes.

Centriole- a small, cylindrical cell organelle, seen near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis, the new pair of centrioles moving ahead of the spindle to opposite poles of the cell as the cell divides: identical in internal structure to a basal body.

Spindle- a spindle-shaped structure, composed of microtubules, that forms near the cell nucleus during mitosis or meiosis and, as it divides, draws the chromosomes to opposite poles of the cell.

Metaphase- the stage in mitosis or meiosis in which the duplicated chromosomes line up along the equatorial plate of the spindle.

Anaphase- the stage in mitosis or meiosis following metaphase in which the daughter chromosomes move away from each other to opposite ends of the cell.

Telophase- the final stage of meiosis or mitosis, in which the separated chromosomes reach the opposite poles of the dividing cell and the nuclei of the daughter cells form around the two sets of chromosomes

Cytokinesis- The division of the cell cytoplasm that usually follows mitotic or meiotic division of the nucleus.

Cyclin- A class of proteins that fluctuate in concentration at specific points during the cell cycle and that regulate the cycle by binding to a kinase.

Cancer- Any of various malignant neoplasms characterized by the proliferation of anaplastic cells that tend to invade surrounding tissue and metastasize to new body sites.

2008-01-03T10:58:00.000-08:00

I am Alexander Bell, I live in Parker. I am 5 foot 2, take a guess at who i am now... Dirt biking, baseball, and paintball is what i do most.