Chapter Fourteen: The Origin of Species

1. What are the two main types of reproductive barriers?

  A: Prezygotic and postzygotic.

2. Who wrote the Origin of Species?

  A: Charles Darwin.

3. What is taxonomy?

  A: Taxonomy is the branch of biology that names and classifies species and groups them into broader categories.


Five Main Facts From The Reading:

1.The origin of species is the source of biological diversity.
2.There are several ways to define a species.
3.Reproductive barriers keep species separate.
4.In allopatric speciation, geographic isolation leads to speciation.
5.Most plant species trace their origin to polyploid speciation.

 

The taxonomy for the common leopard (Panthera Pardus.)

 The Origin of Species Video: http://www.youtube.com/watch?v=vfmOaAz371M


Ten Key Terms:

1.Species - a group of organisms whose members can breed and produce fertile offspring, but who do not produce fertile offspring with members of other groups.
2.Speciation - the emergence of new species.
3.Taxonomy - the branch of biology that names and classifies species and groups them into broader categories.
4.Biological species concept - defines a species as a group of populations whose members have the potential to interbreed in nature and produce fertile offspring.
5.Reproductive isolation - prevents genetic exchange and maintains the hap between species.
6.Reproductive barrier - a biological feature of the organism itself to prevent individuals of closely related species from interbreeding when their ranges overlap.
7.Prezygotic barriers - prevent mating or fertilization between species.
8.Postzygotic barriers - operate after hybrid zygotes are formed.
9.Adaptive radiation - the evolution of many diverse species from a common ancestor
10.Hybrid zones - regions in which members of different species meet and mate, producing at least some hybrid offspring.

Summary:
   This chapter talked about different species and how they gained certain unique traits, as well as traits they share in common. It talks about how certain events can have positive or negative affects on a species, as well as what defines a species. It mentions certain things like the Bottleneck Affect... where a large population is drastically reduced, limiting the gene pool and making it much more distinct from other populations of the same species.

Chapter Thirteen: How Populations Evolve

1. What famous islands housed many of Darwin's most known experiments?

  A: The Galapagos Islands.

2. What is one string of evidence that supports the theory of Evolution?

  A: Similarities in homologous structures between different species.

3. What is the Fossil Record?

  A: It is the sequence in which fossils appear within layers of sedimentary rocks.

Five Main Facts From The Reading: 

1.Charles Darwin proposed natural selection as the mechanism of evolution.
2.Scientists can observe natural selection in action.
3.The study of fossils provides strong evidence for evolution.
4.Homologies indicate patterns of descent that can be shown of an evolutionary tree.
5.Populations are the units of evolution.

The Fossil Record.


Carbon Dating Video: http://www.youtube.com/watch?v=31-P9pcPStg


Ten Key Terms:

1. Evolution - the core theme of biology.
2.Artificial selection - the process by which humans have modified other species by selecting and breeding individuals that possess desired trait.
3.Fossil record - the sequence in which fossils appear within layers of sedimentary rocks-provides some of the strongest evidence of evolution.
4.Biogeography - the geographic distribution of species.
5.Vestigial organs - structures that are of marginal or perhaps no importance to the organism.
6.Population - a group of individuals of the same species living in the same place at the same time.
7.Mutation - a change in the nucleotide sequence of DNA.
8.Genetic drift - a change in the gene pool of a population due to chance.
9.Founder effect - differences in a gene pool of a small colony compared with the original population.
10.Sexual dimorphism - the distinction in appearance.

Summary:
   This chapter is all about the theory of evolution: all life on earth is descended from primitive, single-cell life forms. It also covers natural selection, the process in which the organisms most fit for survival in a certain climate are more likely to pass on their genes, while the less-suitable organisms die along with their traits.

Chapter Twelve: DNA Technology

1. What year was the first crime solved using DNA evidence?

  A: 1986

2. What is the purpose of an enzyme in DNA process?

  A: To "cut and paste" DNA.

3. Has a human ever been clone?

  A: No. Many plants and animals have been cloned in the past, but ethical issues keep the science from being tested on humans.


Five Main Facts From The Reading:

1.Genes can be cloned in recombinant plasmids.
2.Cloned genes can be stored in genomic libraries.
3.Reverse transcriptase can help make genes for cloning.
4.Nucleic acid probes identify clones carrying specific genes.
5.Recombinant cells and organisms can mass-produce gene products. 

A forensic biologist comparing two DNA samples.

 Gene Cloning Video: http://www.youtube.com/watch?v=RrFVdDRX8kU

Ten Key Terms:

1. Biotechnology - the manipulation of organisms or their components to make useful products.
2. DNA technology - methods for studying and manipulating genetic material.
3. Plasmids - small, circular DNA molecules that replicate separately from the much larger bacterial chromosome.
4. Gene cloning - the production of multiple identical copies of a gene-carrying piece of DNA.
5. Genetic engineering - the branch of biotechnology that involves the direct manipulation of genes for practical purposes.
6. Restriction site - the DNA sequence recognized by a particular restriction enzyme.
7. Genomic library - the entire collection og all the cloned DNA fragments from a genome.
8. Vaccine - a harmless variant or derivative of a pathogen that is used to stimulate the immune system to mount a defense against the pathogen.
9. Gene therapy - alteration of an afflicted individual's genes.
10. DNA profiling - the analysis of DNA fragments to determine whether they come from a particular individual.  

Summary: 

  This chapter was all about how genetic information is put to practical use in every day life, and in many different careers. It showed that the ability to understand DNA and it's role in organisms has improved life for many people, and that on some occasions it has even saved lives.  

Chapter Eleven: How Genes are Controlled

1. What are histones?

  A: Histones are small proteins that help DNA packing by keeping the shape of the DNA.

2. What is gene expression?

  A: It is the overall process in which genetic information is transcribed from genes into proteins.

3. What do small RNAs do?

  A: Micro RNAs can bond to complementary sequences on RNA molecules as well as degrade mRNA or block its translation, giving them a part in gene expression.

Five Main Facts From The Reading:

1.Proteins interacting with DNA turn prokaryotic genes on or off in response to environmental changes.
2.DNA packing in eukaryotic chromosomes helps regulate gene expression.  
3.In female mammals, one X chromosome is inactive in each somatic cell.
4.Cascades of gene expression direct the development of an animal.
5.DNA micro-arrays test for the transcription of many genes at once. 

DNA Splicing. 

Gene Regulation Video: The Lac Operon: http://www.youtube.com/watch?v=oBwtxdI1zvk

Ten Key Terms:

 
1. Clone - an individual created by asexual reproduction.
2. Operon - a cluster of genes with related functions, along with a promoter and an operator.
3. Differentiation - an individual's cells become specialized in structure and function.
4. Homeotic gene - a master control gene that regulates batteries of other genes that actually determine the anatomy of parts of the body.
5. DNA microarray - a glass slide with thousands of different kinds of single-stranded DNA fragments fixed to it in a tightly spaced array, or a grid.
6. Nuclear transplantation - the technique used to achieve animal cloning.
7. Reproductive cloning - a type of cloning, which results in birth of a new individual.
8. Therapeutic cloning - when the major aim is to produce embryonic stem cells for therapeutic treatments.
9. Adult stem cells - cells that are able to give rise to many but not all cell types in the organism.
10. Oncogene - a gene, which can cause cancer when present in a single copy in the cell.

Summary: 

  This chapter talked about gene regulation and how the body manages to keep everything under control. It talked about specific enzymes that help regulate reproduction of certain proteins, such as the one that allows the digestion of dairy products.

Chapter Ten: Molecular Biology of the Gene

1. How many nucleotides are found in DNA? What are they called? 

  A: Four: Guanine, cytosine, thymine, and adenine. 

2. Are the nucleotides different in RNA? 

  A: Yes. Uracil replaces thymine in RNA. 

3. Where is DNA (genetic material) located in Eukaryotic organisms? 

  A: In the nucleus of a cell.

Five Main Facts From The Reading: 

  1. tRNA molecules serve as interpreters during translation. 

  2. Genetic information written in codons are translated into amino acid sequences.

  3. DNA replication relies on specific base pairings. 

  4. DNA is a double-stranded helix. 

  5. Transcription produces genetic "messages" in the form of RNA.

Amino Acid Chart. 

Amino Acid Video: http://www.youtube.com/watch?v=tfwdqvqW6n4&feature=related

Ten Key Terms:

 
1. Virus - simply nucleic acid wrapped in a coat of protein.
2. Molecular biology - the study of DNA and how it serves as the chemical basis of heredity.
3.  Nucleotides - long chains of chemical units.
4. DNA Polymerases - the enzyme that links DNA nucleotides to a growing daughter strand.
5. DNA Ligase - the enzyme that links the pieces together into a single DNA strand.
6. Transcription - the transfer of genetic information from DNA into an RNA molecule.
7. Translation - the transfer of the information in the RNA into a protein.
8. Genetic code - the set of the rules giving the correspondence between codons in RNA and amino acids in proteins.
9. RNA splicing - the process of cutting-and-pasting introns and exons.
10. Mutation - any change in the nucleotide sequence of DNA. 

Summary: 

  This chapter deals with molecular biology of a gene and how certain traits are passed from parent to offspring in sexual reproduction, or how the DNA sends a message to its own host body. It covers the central dogma of biology, in other words how DNA from a parent cell is transcribed and translated into a protein that the body needs.

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.