CH 11. vocab

Genetics:

The scientific study of heredity.

True-breeding:

Term used to describe organisms that produce offspring identical to themselves if alowed to self-pollinate.

Trait:

A specific characteristic that varies from one individual to another.

Hybrd:

The offspring of crosses between parents with different traits.

Gene:

Sequence of DNA that codes for a protein and thus determines trait.

Allele:

One of a number of different forms 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:

Term used to refer to an organism that has two identical alleles for a particular trait.

Heterozygous:

Term used to refer to an organism that has two different alleles for the same trait.

Phenotype:

Physical characteristics of an organism.

Genotype:

Genetic makeup of an organism.

Independant Assortment:

Indpendant segregation of genes during the formation of gametes.

Incomplete Dominance:

Situation in which one allele is not completely dominant over another.

Codominance:

Situation in which both alleles of a gene contribute to the phenotype of the organism.

Multiple Alleles:

Three or more alleles of the same gene.

Polygenic Traits:

Trait controlled by two or more genes.

Homologous:

Term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent.

Diploid:
Term used to refer to a cell that contains both sets of homologous chromosomes.

Haploid:

Term used to refer to a cell that contains only a single set of chromosomes and therefore only a single set of genes.

Meiosis:

Process by which 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:

Process in which homologous chomosomes exchange portions of their chromatids during meiosis.

Gene Map:

Diagram showing the relative locations of each known gene on a particular chromosome.

Ch. 10 Questions

p. 243 10-1.

1. Cells divide because the larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell has moving enough nutrients and wastes across the cell membrane.

2. A cells DNA is like the books in a library because they have to make great demands on its available books/genetic information as the town/cell grows.

3. The solution to the problems caused by cell growth is that DNA replication solves the problem of information storage because each daughter cell gets one complete set of genetic information. Cell division also solves the problem of increasing size by reducing cell volume.

4. Each daughter cell has an increased ratio of surface area to volume, so surface area increases more rapidly.

5. Surface Area: 4cm x 4cm x 6= 96cm squared.
Volume: 4cm x 4cm x 4cm= 64cm cubed.
Ratio of surface are to volume: 96/64= 3:2

p. 249 10-2.

1. The main events of the cell cycle are G1, S, and G2.

2. In Prophase, the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus. In Metaphase, the chromosomes line up across the center of the cell. In Anaphase, the chromosome pairs separate and move toward opposite poles. In Telophase, the chromosomes begin to disperse into a tangle of dense material.

3. Interphase in the "in between" period that separate divisions. During which, the cell grows and replicates its DNA and centrioles.

4. Chromosomes are made of DNA and chromatids.

5. It copies the DNA and then separates the contents of the cell into two parts.

6. Cytokinesis in plant cells is similar to cytokinesis in animals cells is that they both separate the cytoplasm and that each part of the divided cytoplasm contains its own nucleus and cytoplasmic organelles. They are different in the way that they separate. In plant cells, a cell plate forms in the middle and separates the cytoplasm. In animal cells, the cytoplasm is pinched into two nearly equal parts.

p. 252 10-3.

1. The chemicals that regulate the cell cycle are proteins called cyclins. When cytoplasm from a cell in mitosis is injected into another cell, the second cell enters mitosis. The reason for this effect is a protein called cyclin, which triggers cell division.

2. When cells do not respond to the signals that normally regulate their growth cancer multiplies and causes tumors.

3. When cells come into contact with other cells, they respond by not growing.

4. Cancer is considered a disease of the cell cycle because cancer cells do not respond to the signals that regulate the growth of most cells.

5. If cyclin was injected into a cell that was in mitosis, then it would counteract the cyclin already in the cell and cause all growth to stop and the cell would be left incomplete in its division process, according to what stage mitosis was in at the time.

p. 257 Ch 10 review.

1. The rate at which materials enter and leave through the cell membrabe depends on the cells:
d) Surface area.

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

3. Pairs of identical chromatids are attached to each other at an area called the:
a) Centriole.

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

5. At the beginning of cell division, a chromosome consists of two:
c) Chromatids.

6. The phase of mitosis during which chromosomes become visible and centrioles separate from one another is:
a) Prophase.

7. Metaphase is best illustrated by:
b)

8. The timing of the cell cycle in eukaryotic cells is controlled by a group of closely related proteins known as:
b) Cyclins.

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

10. Uncontrolled cell division occurs in:
a) Cancer.

Cell Growth and Division

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. http://dictionary.reference.com/browse/cell%20division

Cell Division Video:

Chromatid.

Either of the two strands formed when a chromosome duplicates itself as part of the early stages of cell division. The chromatids are joined together by a single centromere and later separate to become individual chromosomes. ttp://dictionary.reference.com/browse/chromatid

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. http://dictionary.reference.com/browse/centromere

Interphase.

The stage in the development of a cell following mitosis or meiosis, during which the nucleus is not dividing. In cells that will undergo further division, the DNA in the nucleus is duplicated in preparation for the next division. http://dictionary.reference.com/browse/interphase

Cell Cycle.

The series of events involving the growth, replication, and division of a eukaryotic cell. http://dictionary.reference.com/browse/cell%20cycle

Mitosis.

The process in cell division by which the nucleus divides, typically consisting of four stages, and normally resulting in two new nuclei, each of which contains a complete copy of the parental chromosomes. http://dictionary.reference.com/browse/mitosis

Prophase.

The first stage of mitosis, during which the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell. http://dictionary.reference.com/browse/prophase

Centriole.

One of a pair of small cylindrical cell organelles near the nucleus in animal cells; composed of nine triplet microtubules and form the asters during mitosis http://dictionary.reference.com/browse/centriole

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. http://dictionary.reference.com/browse/spindle

Metaphase.

The stage of mitosis and meiosis, following prophase and preceding anaphase, during which the chromosomes are aligned along the metaphase plate. http://dictionary.reference.com/browse/metaphase

Anaphase.

The stage of cell division in mitosis or meiosis in which the doubled set of chromosomes separates into two identical groups that move to opposite ends of the cell. http://dictionary.reference.com/browse/anaphase

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. http://dictionary.reference.com/browse/telophase

Cytokinesis.

The division of the cytoplasm of a cell following the division of the nucleus. http://dictionary.reference.com/browse/cytokinesis

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. http://dictionary.reference.com/browse/cyclin

Cancer.

a malignant and invasive growth or tumor, esp. one originating in epithelium, tending to recur after excision and to metastasize to other sites. http://dictionary.reference.com/browse/cancer

Nikola Tesla

Nikola Tesla is a sophomore, and has been in the Color Guard for two years now. Which is considered a part of the Marching Band. I was born on August 28th, 1992, in Manitoba, Canada. I lived in Canada for eight years of my life. Spent two years living in Tulsa, Oklahoma, and around five years here in Colorado. I have an older sister, who is in her first at Metropolitan State College. I have three pets, one dog and two cats. My favorite animal is a zebra, and my favorite colors are navy, light blue, and brown. I don't really like watching scary movies, and I mainly listen to alternative/screamo/rock music. My favorite band is A Skylit Drive. :)

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