Chapter 1 Homework
Pioneering work in the field of genetics began prior to the 20th century. However, much of the early work relied only upon simple observation. Select the genetics concepts that were discovered before the year 1900.
- Theory of natural selection - Theory of principles of heredity
Most scientists consider the Human Genome Project (HGP) to be the most significant scientific project of the 21st century. Choose the statements that describe the key findings of the Human Genome Project.
-There are approximately three billion base pairs in the human genome. - The human genome contains approximately 25000 genes.
Which of the statements are reasons why rhinoceroses would be a poor choice as model organisms for studying uterine cancer?
1. They produce very few offspring at a time and thus require a lot of time to collect meaningful data. 2. They are inappropriate for experimental manipulation because they are an endangered species. 3. They are needlessly large when smaller, more easily handled organisms, such as mice, are available.
Cell theory began to develop in 1839, following the research of Matthias Schleiden and Theodor Schwann into plant and animal tissues. Both the botanist Schleiden and the physiologist Schwann noticed that every organism they viewed under a microscope, whether plant or animal, was composed of cells. Their observations that all living species are made up of one or more cells led to the early formation of cell theory. Which tenet of cell theory is described by the paragraph about the historical observations of cells?
All organisms are composed of one or more cells
germ-plasm theory
August Weismann cells in the reproductive organs carry a complete set of genetic information that is passed to the egg and sperm
Which statement describes the central dogma of biology?
DNA is transcribed into RNA. RNA is translated into an amino acid sequence.
Match each description to the term it defines.
Gene: - a functional unit of heredity - a chromosomal region that codes for a functional transcript. Allele: -an alternative form of a particular gene Chromosome: - long DNA molecules visible during mitosis - large genetic elements that carries genes essential to cellular function.
Classify each statement as describing a gene, chromosome, or genome.
Gene: - determine a particular characteristic of an organism -codes for a specific protein or RNA Acts as the basic unit of heredity Chromosome: - is a contiguous piece of DNA - is a unit of DNA carrying genetic information encoded in genes - functions to package, organize, and regulate access to DNA -is the largest molecule in the cell -is a linear or circular molecule Genome: - may include plasmids -describes the collection of all of the replicable genetic material of a cell or organism. -each organism has one -encodes all the heritable traits of an organism
Classify each action as belonging to genetics, genomics, or both.
Genetics: -study individual gene function -generate mutants Genomics: -study many genes -assemble a map of all chromosomes - use whole-organism approach Both: -study DNA
Rules of inheritance
Gregor Mendel Alleles of the same gene separate during gamete formation Alleles of different genes are inherited independently
Match the current applications to the appropriate branch of genetics. Not all applications will be placed.
Hereditary Genetics: - observing phenotypes in offspring to understand gene inheritance - tracing pedigrees to determine patterns of gene transmission within a family Population genetics: - calculating allele frequencies to determine changes within gene pools Molecular genetics: - generating plasmids from recombinant DNA - identifying gene mutations associated with a genetic disease
Classify the traits as inherited or acquired.
Inherited: -blonde hair -detached earlobes -Cystic fibrosis -Face shape Acquired: -ability to read -muscle mass gained from strength training -small stature due to malnourishment - fetal alcohol syndrome
Theoretical three-dimensional DNA structure
James Watson and Francis Crick
Polymerase chain reaction
Kary Mullis A method of producing thousands of copies of DNA segment using the enzyme DNA polymerase
Cell theory
Matthias Schleiden and Theodor Schwann idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
Classify descriptions as pertaining to prokaryotic cells, eukaryotic cells, or both.
Prokaryotes: - lack a nucleus - localize DNA in the cytoplasm Eukaryotes: - include algae -contain chloroplasts Both: -contain enzymes
Place each of the molecules in the correct order based on the general flow of genetic information given by the central dogma of molecular biology.
Replication
The blending inheritance theory differs from the concept of preformationism. What does the blending inheritance theory state and how is this different from preformationism?
The egg and sperm contain genetic material that mixes upon conception to produce an intermediate phenotype in the offspring.
How does the structure of DNA encode genetic information?
The sequence of bases
Place each of the molecules in the correct order based on the general flow of genetic information given by the central dogma of molecular biology.
Transcription
Place each of the molecules in the correct order based on the general flow of genetic information given by the central dogma of molecular biology.
Translation
What is the most inclusive definition of a model organism?
an organism with a biological system that is representative of the same system in other organisms
What are the structures in a cell that group genes together, are composed of chromatin (DNA and protein), and become visible under a light microscope during mitosis?
chromosomes
What is the definition of population genetics?
study of collective genes present in a group of the same species
Which of these describes a genome?
the collection of genetic material in a cell or organism
Which term defines the most common form of a naturally occurring trait or allele in a species?
wild type