Chapter 4 - The Cell's Genetic Material Inherited Characteristics Flashcards
Chromatin
A method of storing DNA as nucleosomes (bead shaped structures) where DNA is wrapped around Histone proteins; exists this way for most of cells life to increase surface area of access to genes
Structure of DNA
Double helix
Subunits of DNA
Nucleotides
Components of nucleotides
A ring shaped sugar (deoxyribose), a phosphate group, a nitrogenous base
Pyrimidines
Single ring structures (cytosine and thymine)
Purines
Double ring structures (adenine and guanine)
Translocation
A fragment of one chromosome attaches to a non homologous chromosome
Deletion
A fragment of a chromosome is lost
Duplication
A fragment of a chromosome is repeated
Inversion
Two fragments of a chromosome are switched
Allele
Alternative version of a gene
Anaphase
Third stage of mitosis, when sister chromatids separate to become individual chromosomes
Autosomes
Chromosomes other than the sex chromosomes
Carrier testing
Genetic testing to determine if an individual carries a copy of a mutation that his/her children could inherit
Chromosome
One long, condensed DNA molecule consisting of DNA and protein
Diploid
Having two sets of chromosomes, one set from each parent (2n)
Gametes
Sex cells; eggs and sperm
Gene
Unit of inherited information that carries a code for a specific trait or function
Genotype
Genetic makeup or combination of alleles for an individual
Centromere
Region where two chromatids are joined tightly together
Telomeres
Protective end caps on chromosomes that wear away with each replication, does not contain information for making proteins
Somatic cells
Cells of the body
Prophase
The first stage of mitosis, the sister chromatids become visible, the centrioles move to opposite sides of the nucleus
Metaphase
The second stage of mitosis, the sister chromatids attach to spindle fibres and line up in the middle
Telophase
The fourth stage of mitosis, the chromosomes begin to uncoil, the spindle fibres disappear, and the nuclear envelope begins to re form
Karyotype
A display of all the chromosomes in a cell/individual
Homologous chromosomes
The two chromosomes of each matching pair
Zygote
The fertilized egg that results from the fusion of the nuclei with the cytoplasm from the gametes
Synopsis
The close association between homologous chromosomes in early meiosis
Trisomy
A genetic condition where an individual has 3 copies of a particular chromosome
Non-disjunction
When homologous chromosomes don’t separate during anaphase 1 or 2 of meiosis
