TERMS + DEFINITIONS Flashcards
What is a karyogram?
shows the chromosomes of an organism in homologous pairs of decreasing length
What is a locus?
the positions of genes on a chromosome
What is a genotype
the genetic constitution of an organism?
What is an allele?
one of the possible alternatives of a gene, occupying a specific position on a chromosome, that controls the same trait
the physical and phsyiological traits of an organism
phenotype
What does it mean to be sex-linked?
traits controlled by genes located on one sex chromosome but not the other
What is a diploid?
have nuclei containing two sets of chromosomes, one set from each parent
What is “crossing over”?
exchange of genetic material between non-sister chromatids during meiosis I
What is a genome?
the total genetic material of an organism
What is amniosynthesis?
a procedure used to diagnose genetic defects in the early stages of pregnancy; it involves collecting amniotic fluid using a needle and syringe
What is non-disjunction?
an error during mitosis or meiosis in which both members of a pair of homologous chromosomes or both sister chromatids fail to move apart
What is a haploid?
have one chromosome of each pair (have one full set of chromosomes that are found in its species)
What is cystic fibrosis?
A mutation in a gene that changes a protein that regulates the movement of salt in and out of cells; characterized by the production of thick and sticky mucus.
What is an autosome?
chromosomes that DO NOT determine sex
What is DNA ligase?
A linking enzyme essential for DNA replication
What are homologous chromosomes?
chromosome pairs with genes for the same characteristics at corresponding loci
What is a zygote?
the diploid product of the fusion of haploid gametes (a fertilized egg)
What is a mutation?
a change of the DNA sequence within a gene or chromosome of an organism that results in the creation of a new character or trait not found in the parental type
What are restriction enzymes?
an enzyme that cuts Dna at specific sites, producing small fragments used in genetic engineering
What is chorionic villus sampling?
technique for diagnosing genetic defects while a fetus is in the uterus – a small samples of the placenta is removed and analyzed
What is a gene?
a hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism
What are sematic cells?
all body cells except sex cells (cells producing gametes)
What is a gamete?
one of two haploid reproductive cells, egg or sperm, whose union is necessary in sexual reproduction to produce a diploid zygote
What is PCR?
polymerase chain reaction - a technique for amplifying DNA in vitro by incubating it with primers, DNA polymerase, and nucleotides
