unit 3 dna Flashcards
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.
centromere
the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.
chromatid
each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.
chromosome
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
codon (chart)
A codon is a DNA or RNA sequence of three nucleotides (a trinucleotide) that forms a unit of genomic information encoding a particular amino acid or signaling the termination of protein synthesis (stop signals).
crossing over
one thing crossing over the other
daughter cell
Either of the two cells formed when a cell undergoes cell division by mitosis
deletion
In genetics, a deletion is a mutation in which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome. Wikipedia
diploid
Diploid is a term that refers to the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair. Humans are diploid, and most of the body’s cells contain 23 chromosomes pairs.
DNA
a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
fertilization
the action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote.
frameshift
A frameshift mutation is a genetic mutation caused by indels 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, resulting in a completely different translation from the original. Wikipedia
gamete
A gamete is a reproductive cell of an animal or plant. In animals, female gametes are called ova or egg cells, and male gametes are called sperm. Ova and sperm are haploid cells, with each cell carrying only one copy of each chromosome.
gene
(in informal use) a unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
gene mutation
a change in one or more genes
genetic code
Genetic code refers to the instructions contained in a gene that tell a cell how to make a specific protein
genetic variation
Genetic variation is a term used to describe the variation in the DNA sequence in each of our genomes. Genetic variation is what makes us all unique, whether in terms of hair colour, skin colour or even the shape of our faces.
haploid
Haploid describes a cell that contains a single set of chromosomes. The term haploid can also refer to the number of chromosomes in egg or sperm cells, which are also called gametes.
homologous chromosome
Homologous chromosomes are pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical
independent assortment
The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop.
insertion
the action of inserting a extra thing
meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
meiosis I
During meiosis I, homologous chromosomes first pair with one another and then segregate to different daughter cells
meiosis II
Meiosis I is followed by meiosis II, which resembles mitosis in that the sister chromatids separate and segregate to different daughter cells