Chapter Nine: The Patterns of Inheritance

1. What causes most human genetic disorders?

  A: Most human genetic disorders are recessive.  They range in severity from relatively mild, such as albinism (lack of pigmentation), to life-threatening, such as cystic fibrosis.  Most people who have recessive disorders are born to normal parents who are both heterozygotes.  That is, they are carriers of the recessive allele for the disorder but are phenotypically normal.

2. What are two dominant disorders?

   A: One serious dominant disorder is achondroplasia, a form of dwarfism.  In people with this disorder, the head and torso of the body develop normally, but the arms and legs are short.  Another is Huntington's Disease, a degenerative disorder of the nervous system that usually does not appear until 35 to 45 years of age.

3. What is the chromosome theory of inheritance?

   A: The chromosome theory of inheritance states that genes occupy specific loci on chromosomes and it is the chromosomes that undergo segregation and independent assortment during meiosis.  Thus, it is the behavior of chromosomes during meiosis and fertilization that accounts for inheritance patterns.


Five Main Facts From The Reading:

1. The rule of addition is the probability that an event can occur in two or more alternative ways is the sum of the separate probabilities of the different ways. 
2. An organism's appearance does not always reveal its genetic composition.  An organism's physical traits are called its physical traits.  It's genetic makeup is its genotype.
3. The law of independent assortment states that each pair of alleles segregates independently of other pairs of alleles during gamete formation.
4. Pleiotropy is the property that most genes influence multiple characters.
5. Polygenic inheritance are the additive effects of two or more genes on a single phenotypic character.

this is a punnet square, where the genes of the parents are combined to determine the traits of the potential offspring.

Mendelian Genetics Video: http://www.youtube.com/watch?v=oVl8OH_7QSc

10 Key Terms:

Hybrids- the offspring of two different varieties.
P Generation- the true-breeding parental plants.
F1 Generation- P generation's hybrid offspring.
F2 Generation- offspring when F1 plants self-fertilize or fertilize each other.
Alleles- the alternative versions of a gene.
Homozygous- when an organism has two identical alleles for a gene, it is homozygous for that gene.
Heterozygous- when an organism has two different alleles for a gene, it is heterozygous for that gene.
Dominant allele- allele that determines the organism's appearance.
Recessive allele- allele that has no noticeable affect on the organism's appearance.
Law of Segregation-  A sperm or egg carries only one allele for each inherited character because allele pairs separate from each other during the production of gametes.

Summary: This chapter deals with genetics and the patterns of inheritance that are portrayed when an offspring is produced from two parents. It also deals with sex-linked genes, Mendelian genetics, and the chromosomal basis of inheritance. 

Chapter Eight: The Cellular Basis of Reproduction and Inheritance

Questions:

1. Why is binary fission classified as asexual reproduction?

  A: Because the genetically identical offspring inherit their DNA from a single parent.

2. Contrast cytokinesis in animals with cytokinesis in plants?

  A: In animals, cytokinesis involves a cleavage furrow in which contracting microfilaments pinch the cell in two. In plants, it involves formation of a cell plate, a fusion of vesicles that forms new membrane and walls between the cells.

3.  What is metastasis?

  A: Metastasis is the spread of cancer cells via the circulatory system from their original site of formation to sites in the body.


Five Main Facts From The Reading:

1. Cells arise only from preexisting cells.
2. Prokaryotes reproduce by binary fission.
3. Chromosomes of eukaryotes duplicate with each cell division.
4. Anchorage, cell density, and chemical growth factors affect cell division.
5. Cancer is caused by non-regulation growth in the cells.

This image shows the cell in the final stage of reproduction: cytokinesis, or seperation.





What is Leukemia? http://www.youtube.com/watch?v=JNh1u7P7Ql8


Ten Key Terms:

Asexual Reproduction - the creation of genetically identical offspring by a single parent without the use of sperm or egg.
Chromosomes - the structures that contain most of the organism's DNA.
Sexual Reproduction - offspring that generally resemble their parents more closely than they resemble unrelated individuals of the same species, produced by two parents with the use of sperm and egg.
Chromatin - chromosomes existing as a diffuse mass of long, thing fibers.
Sister Chromatids - identical copies of the DNA molecule.
Centromere - a small "ball" that joins the two chromatids together.
Cell Cycle - an ordered sequence of events that extends from the time a cell is first formed until it's own division into two cells.
Mitotic spindle - a football shaped structure of microtubules that guides the seperation of the two sets of daughter chromosomes.
Centrosomes - clouds of cytoplasmic material that in animal cells contain centrioles.
Anchorage Dependence - most animal cells exhibit this, they must be in contact with a solid surface to divide.


This chapter took us through two cell cycles, Mitosis and Meiosis.. both related to cell division. It explored the steps that lead to cell division: Interphase, Prophase, (Prometaphase) Metaphase, Anaphase, Telophase and Cytokinesis. It explained the differences between Meiosis and Mitosis and well as the differences of cell division in plant and animal cells.

Chapter Seven: Using LIght to Make Food

Questions:

1. How do the reactant molecules of photosynthesis reach the chloroplasts in leaves?

  A: CO2 enters leaves through stromata, and H2O enters the roots and is carried to leaves through veins.

2. What do chloroplasts need to produce sugar from carbon dioxide in the dark?

  A: ATP and NADPH.

3. What is the advantage of the light reactions producing NADPH and ATP on the stroma side of the thylakoid membrane?

  A: The Calvin Cycle, which consumes the NADPH and ATP, occurs in the stromata.


Five Main Facts From The Reading:

1. Photosynthesis occurs in chloroplasts in plant cells.
2. Photosynthesis is a redox process, as is cellular respiration.
3. The two stages of photosynthesis are linked by ATP and NADPH.
4. Visible radiation drives the light reactions.
5. Photosynthesis moderates global warming.

A rudimentary overview of photosynthesis in a sunflower (I hate sunflowers.)

Photosynthesis Light Reactions: http://www.youtube.com/watch?v=hj_WKgnL6MI

Ten Key Terms:

Autotroph - make their own foods and thus sutain themselves without consuming organic molecules derived from any other organisms.

Producers - produce food supply to the biosphere. 

Mesophyll - the green tissue in the interior of the leaf.

Stomata - tiny pores in the leaf through which carbon dioxide enters and oxygen exits.

Stroma - thick fluid in the inner compartment of the chloroplast. 

Thylakoids - a system of interconnected membranous sacs.

Electromagnetic Spectrum - the full range of electromagnetic wavelengths from the very short gamma rays to the very long radio waves.

Wavelength - the distance between the crests of two adjacent waves. 

Photon - a fixed quantity of light energy.

Photosystem - a number of light harvesting complexes surrounding a reaction center complex.

This chapter went over Cellular Respiration's "sister," photosynthesis. Photosynthesis in the plant cells ability to take in water, light, NADP+, ADP,  and phosphorous and convent it into sugar molecules to be stored as a source of food. It took us through Light Reactions II and I and into the Calvin cycle, showing us the reactants and products of all three. 

It also discussed the benefits of photosynthetic organisms to the biosphere, and how it is even being studied as a way to slowly repair the Ozone.

Chapter Six: How Cells Harvest Chemical Energy

Questions:

1. How is breathing related to your cellular respiration?

  A: In breathing, CO2 and O2 are exchanged between your lungs and the air. In cellular respiration, cells use O2 to break down fuel, releasing CO2 as a waste product.

2.  What Cehmical Characteristic of the element oxygen accounts for its function in cellular respiration?

   A: Oxygen is very electronegative, meaning that it is very powerful in pulling electrons from other elements.

3.  What is eh total number of NADH molecules generated during? the complete breakdown of one glucose molecule to six carbon dioxide molecules?

   A: 10 NADH. Two from glycolysis. Two from the grooming of pyruvate. Six from the citric acid cycle.


Five Main Facts From The Reading:

1. Cells tap energy from electrons "falling" from organic fuels to oxygen.
2. The human body uses energy from ATP for all its activities.
3. Glycolysis harvest chemical energy by oxidizing glucose to pyruvate.
4. Most ATP production occurs by oxidative phosphorylation.
5. Fermentation enables cells to produce ATP without oxygen.

                                                   ^Cellular respiration and its cycles. ^

 http://www.youtube.com/watch?v=vlZZUtpyCgQ Cellular Respiration Rap.



Ten Key Terms:

Kilocalories - the quantity of heat required to raise the temperature of one ilogram of water by 1 degree C.
Redox Reaction - the movement of electrons from one molecule to another.
Oxidation - the loss of electrons from one substance in a redox reaction.
Reduction - the addition of electrons to another substance.
Dehydrogenase - enzyme in the process of oxidizing gluclose.
Glycolysis - step one in cellular respiration.
The citric acid (krebs) cycle - step two in cellular respiration.
Oxidative Phosphorylation - the final step in cellular respiration.
ATP Synthase - the enzyme that generates most of the ATP in cellular respiration.
Pyruvate - a three carbon sugar from glucose that enters the citric acid cycle.



This chapter was an in dept look at cellular respiration, the cycle that keeps the cells in our body function. It walked us through the three levels, Glycolysis, the citric acid cycle, and oxidative phosphorylation while showing us how each step works and what the reactants and products where.