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