Chapter Nine

Key Terms:
Character- a heritable feature that varies among individuals.
Trait- Each variatn for a character
Self-Fertilize- sperm- carrying pollen grains released from the stamens land on the egg containing carpel of the same flower.
Cross fertilization-fertilizaition of one plant by pollen from a different plant.
true-breeding- varieties for which self fertilizaiton produced offspring all identical to the parent.
hybrids- usually come from cross-fertilization.
alleles- alternative versions of a gene.
homozygous- an organism that has two identical alleles for a gene.
heterozygous- an organism that has two different alleles for a gene.
Law of segregation- When sperma nd egg unite at fertilizaiton, each conributes an allele restoring the paired condition in the offspring.

Reading Journal:
1) why did Mendel use pea? Short life span, bisexual, many traits known and cross- and self-pollinating.
2) how did Mendel work on peas? he controled other characters but make one variable, by cross-pollination, then record the data.
3) why did Mendel record so many data? for the sake of geting accurate datas

Five Facts:
1) Mendel used the scientific approach to identify two laws of inheritance.
2)The laws of probability govern Mendelian inheritance.
3)Inheritance patterns are often more complex than predicted by simple Mendelian genetics.
4)Many human traits follow Mendelian patterns of inheritance.
5)Inheritance is pretty random but follow laws.

In the 1860s, Gregor Mendel formulated a theory of inheritance based on experiments with garden peas, introduced that parents pass on to their offspring discrete genes that retain their identity through generations. In a diploid organism, the two allels of a gene separates during gamete formation. Each sperm or egg carries only one allele of each pair with a ratio of F2 3:1. In heterozgotes, the two alleles are different , and the dominant allel phenotypic effect of the recessive allele. Homozygotes have identical alleles of a given gene and are true-breeding. Each pair of alleles segregates into gametes independently of the pair of allels for any other gene. in a cross between dihybrids, the offspring have four phenotypes in a 9:3:3:1 ratio.
The expresion of a genotype can be affected by environmental influences. The phenotypic range of a particular genotype is called its norm of reaction. Polygenic characters that are also influenced by the environment are called multifactorial character.

Here is an example of genetics. Taco tongue, or tongue rolling, is a recessive gene that can be carried on from parent to child.












Video Link Mendel:
http://www.youtube.com/watch?v=EvR_Sdm1orU

Chapter Eight

Key Terms:
Haploid cells- half the number of chromosomes (23 for humans)
Control mechanisms- cells divide rapidly, often in the absence of growth factors
Polyploid- many chromosomes
Nondisjunction- An accident of meiosis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fail to separate at anaphase.
Diploid- In an organism that reproduces sexually, containing two homologous sets of chromosomes, one from each parent.
Karyotype- shows stained and magnified versions of chromosomes
Chiasma- The ricroscopically visible site where crossing over has occured between chromatids of homologous chromosomes during prophase I of meiosis.
Getnetic recombination- the production of gene combinations different from those carried by the original chromosomes.
Sex Chromosomes- the X and Y chromosomes that determines a chromosomes sex (XX female and XY male)
Autosomes- other 22 pairs of chromosomes
deletion-loss of a chromosomal segment
duplication- a copy of a chromosomal segment
inversion- reversal of chromosomes
translocation-can be reciprocal;switched

Reading Journal:
1) What 'accidents' can occur during meiosis and what is a possible result?
You can have more chromosomes than you needed. this would result in a slight mutation and variation.
2) How are Karyotypes produced? Karyotypes are produced from dividing white blood cells, stoppped at metaphase.
3) How does cancer form? Growth is not inhibited by other cells, and tumors form and eventually spread through the blood system if it is not caught early.

Five Facts:
1)Carcinomas arise in external or internal body coverings.
2)Trisomy 21 involves in the inheritance of three copies of chromosome 21
3)Altered chromosomes carried by gametes cause birth defects
4)Chromosomal alterations in somatic cells can lead to cancer
5)Locacalized tumors can be treated with surgery or radiation, while Chemotherapy is used for metastic tumors.

Cell Division is important to the reproduction of cells and organisms, because new cells can only come from already existing cells.
Mitosis distributes duplicated chromosomes into two daughter cells. After chromosomes form, the spindle fiber appears and the microtubles move to the middle of cell. The spindle fiber then separates the sister chromatids apart and two nuclei form. A cleavage furrow will appear in animal cells, a cell plate in plant cells. Cytokinesis takes place, and fully separates the cytoplasm apart. Some important functions for mitosis include for growth, replacement, asexual reprodution, and occurs in somatic cells.
Meiosis occurs for sex cells. All of what takes place during mitosis occurs during meiosis, but with an extra process after. Also happening during meiosis I, is a process called crossing over. in crossing over, homologous chromosomes exchange the same segements. Meiosis II just separateseach homologous pair and produces two daughter cells. Separation of homologous chromosomes(crossing over) during meiosis leads to genetic differences between gametes.
In down syndrome, or trisomy 21, the incidence increases with the age of the mother. Trisomy 21 is caused by having an extra copy of chromosome 21. Down syndrome is characterized by
characteristic facial features, susceptibility to disease, shortened life span, mental retardation, and variation in characteristics.
Cancer cells are characterized by dividing excessively, where growth is not inhibited by other cells. These form masses of tissue called tumors. There are two types of tumors, malignant, which can invade other cells, and benign, which are less harmful. Radiation and chemotherapy are the most effective ways of treating cancer because they are able to interfere with cell division, thus stopping the cancer cells from growing.

Here is a karyotype of Trisomy 21, Aka Down syndrome. Here, there is one extra copy of chromosome 21. Other types of syndromes can occur if there is an extra copy of any chromosome, such as trisomy 13, trisomy 18, etc.
A karyotype is formed by dividing a white blood cell and stopping it during metaphase, so that it is easier to read.





Video Link Meiosis:
dividing white blood cells, stoppped at metaphase

Chapter Seven

Key Terms:
Autorophs- 'self feeders' they make their own food and sustain themselves without consuming organic molecules derived from any other organisms.
Photoautotrophs- organisms that produce organic molecules from inorganic molecules using the energy of light.
Producers- organisms that produce its food supply.
Stroma- a thick fluid that is filled in an envelope of two membranes.
Wavelength- the distance between the crests of two adjacent waves. The shorter the wavelength, the greater the energy. the longer the wavelength, the lesser the energy.
Photon- is a fixed quanity of light energy.
Photosystem- consists of a number of light-harvesting complexes surrounding a reaction center complex.
Photorespiration- the breakdown of a two carbon compound produced by the Calvin cycle. photorespiration produces no sugar molecules or ATP.
Electromagnetic spectrum- the full of range of electromagnetic wavelengths from the very short gamma rays to very long wavelength radio waves.
Carbon fixation-the incorporation of carbon from CO2 into organic compounds.

Reading Journal: 1) Where does photosynthesis occur? Photosynthesis occurs in the leaves, within chloroplasts, which contain stroma and grana.
2) What are the two stages of Photosynthesis? Light reactions, which convert light energy to ochemical energy, and the Calvin Cycle, which occur in the stroma.
3) How are the mitrochondria and photosynthesis similar? Both have an electron transport chain, ATP synthase, thylakoid space, ATP, and stroma. They also have a double membrane and contain their own ribosomes.

Five Facts: 1) Photosynthesis consumes water and produces oxygen.
2) Water is oxidized and carbon dioxide is reduced in photosynthesis. 3) The role of NADP in photosynthesis is to accept electrons and carry them to the Calvin Cycle. 4) Plants use the sugar they break downby using it as energy in cellular respiration, store excess sugar as starch, and use it as raw material for making other molecules. 5) Chemiosmosis is used in both Photosynthesis and cellualar respiration.

Photosynthesis contains two cycles, the light reaction and the calvin cycle. There are two photosystems as well, which absorb photons and transfer energy to the chlorophyll. The electrons are excited and passsed from electron acceptors to the electron transport chain, which is shuttled form photosystem II to I. As it is traveling the electron transport chain, it provides energy to make ATP. NADP is now reduced to NADPH, and photosystem II regains electrons by splitting water. During the Light reaction stage, ATP is synthesized during chemiosmosis.
The calvin cycle,occurs in the stroma. It consists of carbon fixation, reduction, release sugar(G3P), and regeneration of RuBP. these electrons are used to build glucose and other organic molecules.
There are also different kind of plants: C3, C4, CAM plants. C3 plants include soybeans, oats, wheat, and rice. these plants produce the three carbon 3-PGA. Stomata closes to reduce the water loss and O2 builds up in the leaf. C4 Plants are able to consume CO2 and go through the calvin cycle during all time of day. CAM plants only consume CO2 at night and go through the calvin cycle during the day.

Here is the basic overview of photosynthesis: the carbon dioxide enters the leaf through the stomata. the chloroplasts capture the light energy and the water enters the leaf. The products of photosynthesis include chemical energy and sugar.















Video Link Photosynthesis:
http://www.youtube.com/watch?v=C1_uez5WX1o