Chapter 1 Flashcards
This project aimed to decode all of the DNA found in all human chromosomes
Human Genome Project
What year did the Human Genome Project start?
1990
What two bodies coordinated the Human Genome Project?
National Institutes of Health (NIH) and Department of Energy (DOE)
How many chromosomes do humans have?
46 (23 pairs)
What length is human DNA?
2 meters
Approximately how many genes do humans have?
22,000
Approximately how many DNA base pairs are in each set of human chromosomes?
3 billion
When was the complete sequence of the human genome published?
2003
What was the accuracy of the Human Genome Project?
99.99%
This project was launched to catalog human genetic variation
1000 Genomes Project
In what year was the sequencing of 2,500 genomes described in Nature?
2015
What are three examples of fundamental molecular details that the study of the human genome provides?
- How many genes humans have; 2. How cells develop into complex tissue; 3. How defective genes cause disease
This genetic technology is often considered controversial
Mammalian cloning
In what year was the first mammal cloned?
1997
Which scientist, along with his colleagues, was the first to clone a mammal?
Ian Wilmut
Fear that cloning technology could be applied to humans led to these
Legislative bans on human cloning
Mice can be genetically modified with genes from this animal to emit a green fluorescent glow upon exposure to blue or ultraviolet light
Jellyfish
This is the study of heredity and variation
Genetics
Along with this concept, genetics is the unifying discipline in biology
Evolution
Genetics is centered on the study of these
Genes
This is classically defined as the “unit” of heredity
Gene
What is the modern definition of a gene?
Segment of DNA that produces a functional product such as polypeptide
Genes provide the blueprint that determines these of an organism
Traits
These are the observable characteristics of an organism
Traits
All cells are constructed from these
Small organic molecules
Small organic molecules are linked together by these to form larger molecules
Chemical bonds
What are the four main types of large molecules contained in cells?
Nucleic acids, proteins, carbohydrates, lipids
Nucleic acids, proteins and carbohydrates are considered this type of molecule
Macromolecule
These are smaller molecules that construct polymers
Monomers
These form as a result of the interaction of molecules and macromolecules
Cellular structures
These are used to make long strands of DNA
Nucleotide building blocks
DNA strands associate with proteins to form these
Chromosomes
In what part of the cell are chromosomes contained?
Nucleus
This is composed of a linear sequence of amino acids
Polypeptide
Each of these is composed of one or more polypeptides
Protein
The characteristics of a cell largely depend on these
The proteins it produces
This is all of the proteins that a cell makes at a given time
Proteome
What are three functions of proteins?
Structure, transport, enzyme
Tubulin is an example of this type of protein
Structural protein
Tubulin aggregates to form these
Microtubules
Tubulin/microtubules play a part in these two roles in the cell
Shape and movement
Where in the cell are transport proteins found?
Cell membrane
What role do transport proteins play in the cell?
Aid in transport of ions/small molecules across cell membrane
These are biological catalysts
Enzymes
Enzymes/catalysts accelerate these
Chemical reactions
What are the two types of enzyme?
Catabolic and anabolic
This category of enzymes is involved in the breakdown of large molecules into smaller ones
Catabolic enzymes
Catabolic enzyme reactions provide this for cell activities
Energy
This category of enzymes is involved in the synthesis of large molecules from smaller ones
Anabolic enzymes
Anabolic enzyme reactions provide components for this
Construction of the cell
This is the genetic material in all living organisms
Deoxyribonucleic acid (DNA)
Some viruses use this molecule as their genetic material, as a DNA alternative
RNA
DNA encodes the information required to synthesize these
Cellular proteins
What aspect of DNA allows it to encode information?
Molecular structure
A DNA strand is a polymer of these monomers
Nucleotides
What are the four nitrogenous bases that make up nucleotides?
Adenine, thymine, cytosine, guanine
Genetic information is stored in this along the DNA molecule
Lineaer sequence of ATCG bases
This directs the order of amino acids
Genetic code
How many bases are in each amino acid code?
3
DNA in living cells is contained within these large structures
Chromosomes
How many chromosomes do human cells have?
46
Each chromosome is a complex of these two components
DNA and proteins
How many nucleotides per DNA strand does an average human chromosome contain?
> 100 million nucleotides
How many different genes are contained in the average human chromosome?
~1000
DNA information is accessed during this process
Gene expression
What are the two steps of gene expression?
Transcription and translation
In this gene expression step, the genetic information in DNA is copied into a nucleotide sequence of RNA
Transcription
In this step of gene expression, the nucleotide sequence in RNA provides information to make the amino acid sequence of a protein
Translation
This is any characteristic that an organism displays
Trait
What are three types of traits that can be identified in an organism?
Morphological, physiological, behavioral
These traits affect the appearance of an organism
Morphological traits
These traits affect the function of an organism
Physiological traits
These traits affect the way an organism responds to the environment
Behavioral traits
This process within cells leads to an organism’s traits
Molecular expression of genes
What are the four levels of biological organization spanned by the relationship between genes and traits?
Molecular, cellular, organism, population
These are expressed at the molecular level
Genes
These function at the cellular level
Proteins
These are often observed at the organism level
Traits
These can be studied at the population level
Genes/traits within a particular species
This refers to the differences in inherited traits among individuals within a population
Genetic variation
These are contrasting forms within a single species
Morphs
Genetic variation is a result of this
Changes to DNA at molecular level
What are three different types of changes DNA can undergo at the molecular level?
- Gene mutations; 2. Chromosome structure changes; 3. Chromosome number changes
This type of DNA change leads to a difference in gene sequences
Gene mutation
These are the result of genetic mutation leading to two or more expression forms of the same gene
Alleles
In this type of DNA change, large segments of a chromosome may be lost, duplicated or reattached to another chromosome
Chromosome structure change
In this type of DNA change, single chromosomes may be lost or gained
Chromosome number change
How many chromosomes does a person with Down syndrome have?
47
Can entire extra sets of chromosomes be inherited?
Yes
How many sets of chromosomes does cultivated wheat have?
6
Do an individual’s traits result from its genes alone?
No
Traits are an interaction between these two factors
Genes and environment
Can an individual’s environment dictate whether or not a disease is manifested?
Yes
This is a human genetic disease involving genes and the environment that involves a gene encoding the enzyme phenylalanine
Phenylketonuria (PKU)
The enzyme phenylalanine hydroxylase converts phenylalanine to this
Tyrosine
If a human has one functional copy of the gene that encodes phenylalanine hydroxylase, can they metabolize phenylalanine?
Yes
If a human has two functional copies of the gene that encodes phenylalanine hydroxylase, can they metabolize phenylalanine?
Yes
If a human has two copies of a rare inactive allele of the gene that encodes phenylalanine hydroxylase, can they metabolize phenylalanine?
No
In humans with phenylketonuria (PKU), these accumulate in the absence of the enzyme phenylalanine hydroxylase
Phenylketones
What is the treatment for phenylketonuria?
Strict dietary restriction (phenylalanine-free diet)
This scientist provided the foundation for the science of genetics in the mid-19th century
Gregor Mendel
Sexually reproducing species are commonly this, meaning they have two copies of each chromosome
Diploid
What is the term for chromosome copies?
Homologs
Do homologs contain the same genes?
Yes
Do homologs always contain the same alleles?
No
Gametes are usually this, meaning they have one copy of each chromosome
Haploid
This process in sexual reproduction restores the diploid number of chromosomes
Fertilization of egg by sperm
Sexual reproduction enhances this in offspring
Genetic variation
Can sexual reproduction result in combinations of traits not found in either parent?
Yes
What is a common exception to the rule that all human chromosomes form 23 homologous pairs?
X and Y chromosomes of human males
Are sperm and egg cells haploid or diploid?
Haploid
This is the change of the genetic makeup of a population over many generations
Biological evolution
This is the process in which individuals with greater reproductive success are more likely to pass their genes to future generations
Natural selection
Can random mutations lead to beneficial alleles in some individuals in a population?
Yes
Passing of beneficial alleles to subsequent generations can lead to this
Accumulation of genetic changes
Researchers often study these so they can compare their research results
Model organisms
What are the three traditional fields of genetics?
- Transmission genetics; 2. Molecular genetics; 3. Population genetics
This field of genetics explores the inheritance patterns of traits as they are passed from parents to offspring
Transmission genetics
What is the oldest field of genetics?
Transmission genetics
When was the conceptual framework for transmission genetics provided by Gregor Mendel
1860s
Genetic determinants pass from parent to offspring as these, that are now termed genes
Discrete units
The basic experiment approach in transmission genetics is this, in which two selected individuals are bred to each other
Genetic cross
Are traits analyzed over only one generation in transmission genetics?
No
Is analysis in transmission genetics often qualitative or quantitative in nature?
Quantitative
This field of genetics focuses on a biochemical understanding of the hereditary material
Molecular genetics
What are two major areas of study in molecular genetics?
- Gene organization/function; 2. Detailed analysis of DNA/RNA/proteins
Molecular geneticists typically employ this approach to research
Genetic approach
These genes have abnormal function
Mutant genes
Can mutations reveal the role of a gene in creating a trait?
Yes
This field of genetics is concerned with genetic variation and its role in evolution
Population genetics
Population genetics deals with the genetic variation of populations and how that variation is related to this
The environment
Population geneticists develop these to explain the prevalence of certain alleles within populations
Mathematical theories
