Chapter 3 Flashcards
Genetics
The study of the basic structure and processes of DNA
Genomics
The study of DNA including all associated molecules, chemicals and evolutionary patterns
Human Genome
All the DNA in the human species
Heredity
The passing of biological information from generation to generation (through reproduction)
Deoxyribonucleic Acid (DNA)
The chemical compound found in most living organisms, that contains basic information for the structure of life
Nucleotide Bases
The four chemical bases that make up the core portion of DNA (adenine, cytosine, guanine, and thymine)
Chromosomes
Complex structures that house the supercoiled DNA in the nucleus
Diploid
Having 46 chromosomes, arranged in 23 pairs
Three Main Function of DNA
Replication (Making copies of itself), protein synthesis (helping in the creation of the molecules that make up organisms), and regulation (in the first two functions)
Replication
The process by which DNA copies itself
Mitosis
The process of cell division and replication
- Replaces body cells as they die or are otherwise lost
- Creates two diploid cells from one mother cell
Meiosis
The production of gametes (haploid cells) [Sex cells]
-Creates four haploid cells w/23 chromosomes each
Haploid
Having 23 single chromosomes half the genetic complement; found in gametes
Recombination
Shuffling of maternal and paternal chromosomes during meiosis
-Different combinations of the chromosomes from the parents
Crossing Over
Genetic material on a chromosome from one parent is exchanged with the same section of the matching chromosome from the other parent
Proteins
Building blocks of organic life
-Composed of a string of amino acids
Protein Synthesis
The process by which the nucleotide “message” is taken from a gene, transcribed, and translated into a protein
Amino Acids
Building blocks of proteins
Polypeptide
A string of amino acids that folds in on itself and becomes a protein
Triplet
- Three-nucleotide sequence
- A sequence for an amino acid
- Each triplet is a specific amino acid
Transcription
Copying the DNA message to RNA
Ribonucleic Acid (RNA)
A molecule similiar to DNA that is responsible for taking the message from the DNA in the nucleus of a cell to the ribosome in the cytoplasm and facilitating translation into a protein
Messenger RNA (mRNA)
The form of RNA that takes the transcribed DNA message to the ribosome
Codon
A three-nucleotide sequence in which the DNA’s triplet code is written onto the mRNA
Translation
Converting the mRNA message into a protein
Ribosome
site of protein synthesis
Transfer RNA (tRNA)
Form of RNA that brings amino acids to the ribosome
Anticodon
Three-nucleotide sequence on a tRNA molecule that helps match the appropriate amino acid with a specific mRNA codon
Gene
Segement of DNA that contains the sequence for a protein
Allele
A variant sequence of nucleotides in a gene; a form of gene
Genotype
The alleles in an organism’s DNA
Phenotype
An organism’s observable, measurable traits
Homozygous
having the same allele at both loci for the same gene
Heterozygous
having different alleles at both loci for the same gene
Locus
The place on a chromosome where a specific gene occurs
Polygenic
The situation wherein many genes combine to have one effect
Pleiotropic
The situation wherein one gene has many effects
Inactive DNA
- has a regulatory purpose
- serves as a reserve for genetic variation
Enzyme
molecules that help to start, regulate, maintain, and stop the processes (of DNA)
Translocation
Parts of different chromosomes are exchanged
Epigenetics
Examines how genes are turned on and off during gene expression (non-genetic influences)
- different genes are active in different types of cells
- environmental factors can affect the activation of genes
Mendel’s Law of Segregation
- Gametes only have one pair of each gene
- When sexual reproduction occurs, the alleles from each parent are paired
Mendel’s Law of Independent Assortment
Genes are inherited independently of one another
Co-Dominant Alleles
Both alleles are expressed
Polygenic Traits
Traits resulting from the interaction of several alleles to produce different genotypes and phenotypes
-Complex trait
Pleiotropy
One gene has an effect on multiple traits
