Chapter 3 - Genetics Flashcards
Adenine
One of the nitrogen bases that make up DNA and RNA; pairs with Thymine in DNA and uracil in RNA
amino acids
Organic molecules combined in a specific sequence by the ribosomes form a protein
antibodies
Molecules that form as part of the primary immune response to the presence of foreign substances; they attach to the foreign antigens
antigens
specific proteins, on the surface of cells, that stimulate the immune system’s antibody production
autosomes
All chromosomes, except the sex chromosomes, that occur in pairs in all somatic cells
coding DNA
Sequences of a gene’s DNAthat are coded to produce a specific protein and are transcribed and translated during protein synthesis
codominance
Refers to two different alleles that are equally dominant; both are fully expressed in a heterozygote’s phenotype
codons
The sequences of three nitrogen bases carried by mRNA that are coded to produce specific amino acids in protein synthesis
complementary bases
The predictable pairing of nitrogen bases in the structure of DNA and RNA, such that adenine and thymine always pair together and cytosine and guanine pair together
crossing-over
The process by which homologous chromosomes partially wrap around each other and exchange genetic information during meiosis
cytoplasm
The jellylike substance inside the cell membrane that surrounds the nucleus and in which the organelles are suspended
cytosine
One of the nitrogen bases that make up DNA and RNA; it pairs with guanine
diploid
A cell that has a full complement of paired chromosomes
epigenetic
Refers to chemical changes in the genome affecting how the underlying DNA is used in production of proteins, but without altering the DNA sequences
essential amino acids
Those amino acids that cannot be synthesized in the body; they must be supplied by the diet
gametes
Sexual reproductive cells, ova, and sperm, that have a haploid number of chromosomes and that can unite with a gamete of the opposite type to form a new organism
genome
The complete set of genetic information for an organism or species that represents all the inheritable traits
genomics
The branch of genetics that studies species’ genomes
guanine
One of the nitrogen bases that make up DNA and RNA; it pairs with cytosine
haplogroups
A large set of haplotypes, such as the y chromosome or mitochondrial DNA, that may be used to define a population
haploid
A cell that has a single set of unpaired chromosomes; half of the number of chromosomes as a diploid cell
haplotypes
A group of alleles that tend to be inherited as a unit due to their closely spaced loci on a single chromosome
heterozygous
Refers to the condition in which the two alleles of a pair of alleles at a single locus on homologous chromosomes are different
homeotic genes (Hox)
Also known as homeobox genes, they are responsible for differentiating the specific segments of the body, such as the head, tail, and limbs, during the embryological development
homologous
Refers to each set of paired chromosomes in the genome
homozygous
Refers to the condition in which the two alleles of a pair of alleles at a single locus on homologous chromosomes are the same
law of segregation
Mendel’s first law which asserts that the two alleles for any given gene are inherited, one from each parent; during gamete production, only one of the two alleles will be present in each ovum or sperm
locus
The location on a chromosome of a specific gene
meiosis
The production of gametes through one DNA replication and two cell divisions, creating four haploid gametic cells
mitochondria
Energy-producing (ATP) organelles in eukaryotic cells; they possess their own independent DNA.
mitosis
The process of cellular and nuclear division that creates two identical diploid daughter cells
noncoding DNA
Sequences of a gene’s DNA (also known as introns) that are not coded to produce specific proteins and are excised before protein synthesis
nucleotide
The building block of DNA and RNA, composed of a sugar, a phosphate group, and one of four nitrogen bases
nucleus
A membrane-bound structure in eukaryotic cells that contains the genetic material
pleiotropy
A single gene can have multiple effects
polygenic
Refers to one phenotypic trait that is affected by two or more genes
polymorphism
Refers to the presence of two or more alleles at a locus and where the frequency of the alleles is greater than 1% in the population
recombination
The exchange of genetic material between homologous chromosomes, resulting from a crossover event
regulatory genes
Those genes that determine when structural genes and other regulatory genes are turned on and off for protein synthesis
replication
The process of copying nuclear DNA prior to cell division, so that each new daughter cell receives a complete complement of DNA
ribonucleic acid
A single-stranded molecule involved in protein synthesis consisting of a phosphate, ribose sugar, and one of four nitrogen bases
ribosomes
The organelles attached to the surface of the endoplasmic reticulum located in the cytoplasm of a cell; they are the site of protein synthesis
sex chromosomes
The pair of chromosomes that determine an organism’s biological sex
single nucleotide polymorphisms
Variations in the DNA sequence due to the change of a single nitrogen base
somatic cells
Diploid cells that form the organs, tissues, and other parts of an organism’s body
structural genes
Genes coded to produce particular products, such as an enzyme or hormone, rather than regulatory proteins
thymine
One of four nitrogen bases that make up DNA; it pairs with adenine
transcription
The first step of protein synthesis, involving the creation of mRNA based on the DNA template
translation
The second step of protein synthesis, involving the transfer of amino acids by tRNA to the ribosomes, which are then added to the protein chain
translocations
Rearrangements of chromosomes due to the insertion of genetic material from one chromosome to another
uracil
One of four nitrogen bases that make up RNA; it pairs with adenine
zygote
The cell that results from a sperm’s fertilization of an ovum
