DNA STRUCTURE
When do cells duplicate their DNA?
interphase
what is a punnet square?
a table in which all of the possible outcomes for a genetic cross between two individuals with known genotypes are given
what is an mutation?
Any change in the DNA sequence of a cell
What is meiosis?
a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells
what does ligase mean?
by hydrogen bonds between pairs of bases: adenine pairs with thymine, and cytosine pairs with guanine.
what goes on a punnet square? (What is being compared/used)
parents for an offspring
what is an example of a mutation?
down syndrome, sickle cell Anemia, albinism, etc.
what are the 4 stages of meiosis?
prophase, metaphase, anaphase, and telophase.
what does haploid mean?
a single set of chromosomes
How do cells make accurate copies of DNA?
through a process called DNA replication
What is an allele?
one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
Explain difference between gene mutation and chromosomal mutation
Gene mutations involve a change in nucleotide sequence of DNA. Chromosomal mutations are generally more extensive and involve changes to chromosomal structure or chromosome number.
What is the order of the 4 phases in meiosis?
prophase I, metaphase I, anaphase I, and telophase I
what does diploid mean?
the presence of two complete sets of chromosomes in an organism's cells, with each parent contributing a chromosome to each pair
What is a "strand" of DNA?
two linked strands that wind around each other to resemble a twisted ladder — a shape known as a double helix.
The allele for blue eyes is "t" while the allele for brown eyes is "T". What percentage of offspring produced by two parents with blue eyes would also have blue eyes?
100%
Define frameshift mutation
A genetic mutation caused by indels (insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three. Due to the triplet nature of gene expression by codons, the insertion or deletion can change the reading frame (the grouping of the codons), resulting in a completely different translation from the original.
In what two ways does meiosis produce genetic variation?
independent assortment and crossing over (recombination).
what does offspring mean?
a child
What information is coded into DNA?
Genetic Code
What are the phenotypes of the cross between two homozygous parents, one with a long neck and one with a short neck
100% long necks
A type of point mutation in which a single nucleotide change results in a codon that codes for a different amino acid. It is a type of nonsynonymous substitution.
missense mutation
What is the end result of meiosis?
there are four haploid daughter cells that go on to develop into either sperm or egg cells.
what is the name of where DNA is stored?
cell nucleus