Flashcards in Lecture--Chapter 1 Deck (45):
unit of heredity
all the DNA contained within the chromosomes
Approximately how many genes code for proteins that perform most life functions?
20 000 - 25 000
Approximately how many DNA base pairs per set of chromosomes?
The four major groups of cellular macromolecules are:
4. nucleic acids
What are lipids?
Molecules that form fats, phospholipids, waxes, steroids; function in energy metabolism and components of membranes.
What are carbohydrates?
Molecules composed of hydrocarbon-rings, which form monosaccharides and polysaccharides; function in energy metabolism and storage polymer formation.
What is an example of a monosaccharide?
What is an example of a polysaccharide?
What are proteins?
polymers of amino acids (polypeptides); function in cell structures, immune defense, as enzymes; proteome
What is a proteome?
All of the proteins that an organism can make.
What are nucleic acids?
DNA or RNA; polymers of nucleotides; hereditary information, direct protein synthesis.
Each nucleotide of DNA contains one:
What are the nitrogenous bases?
What is a nucleotide?
a molecule containing a sugar, a phosphate, and a nitrogenous base
What is a triplet code?
genetic information stored in the linear sequence of bases
ATG (codes for methionine)
What are the three different traits?
1. morphological traits
2. physiological traits
3. behavioural traits
affect the appearance, form, and/or structure of an organism
affect how an organism functions
affect the ways an organism responds to the environment
Traits are affected by:
the gene allele that is expressed
Traits are expressed:
at different levels of biological organisation
Traits are governed:
both by genes and by the environment
What is a morph?
A contrasting form within a single species (2 or more phenotypes of the same species that occupy the same habitat at the same time, within a population with random mating).
Genetic variation is a result of different types of changes at the DNA molecular level:
1. gene mutations
2. chromosomal mutations
What are gene mutations?
any change in the local DNA sequence as simple as a single nucleotide change; create new alleles
What are chromosomal mutations?
any change in the structure of the chromosome; deletions, inversion, translocations, or duplications
What is aneuploidy?
chromosomes lost or gained
Define biological evolution:
The genetic makeup of a population can change over many generations.
Define natural selection:
The gradual, non-random process by which biological traits become either more or less common in a population as a function of differential reproduction of their bearers; beneficial alleles have a higher probability of being passed onto subsequent generations.
Random DNA mutations lead to:
1. neutral alleles
2. beneficial alleles
3. deleterious alleles
no advantage or disadvantage to the individual
are advantageous to individuals since they make them better able to compete for resources and reproduce
make individuals less able to compete for resources and reproduce
What are the 2 different experimental approaches that genetics research uses?
1. hypothesis testing
2. discovery-based science
What are the three fields of genetics research?
1. transmission genetics
2. molecular genetics
3. population genetics
examines how traits are passed from one generation to the next
deals with the molecular features of DNA and how these underlie gene expression
deals with the genetic composition of populations and how it changes over time and space
What does transmission genetics entail?
1. looks at patterns of inheritance (Mendelian and non-Mendelian)
2. the basic experimental approach in transmission genetics is the genetic cross
What is the genetic cross?
the mating of 2 individuals and analysis of the traits of their offspring over several generations
What does molecular genetics entail?
1. goal is to describe the molecular features of gene structure and function, scaling from DNA molecules to whole genomes
2. molecular technologies allow the introduction of genes into animals and plants--treatment for genetic diseases; agriculture modification of animals and plants in various ways