Biology Flashcards
Complementary base pair
A pair of bases that can join to make the rungs of the DNA ladder-
(A-T) (G-C)
DNA
(Deoxyribose nucleic acid) a nucleic acid with deoxyribose sugar and phosphate as the back bone
Gene
A section of DNA that carries the genetic code for a particular characteristic
Nitrogen-rich base
Part of a nucleotide; the four types are adenine (A), guanine (G), cytosine (C), and thymine (T)
Nucleotides
The building blocks of DNA
Phosphate group
One of the parts that make up a nucleotide
Autosomes
All the chromosomes in body cells
Centromere
where the two chromatids are joined together in a chromosome
Chromatid
One of the strands of a chromosome following replication
Diploid number
The number of chromosomes in the body cells; two sets or 2N
Haploid number
The number of chromosomes in gametes(sex cells); one set or N
Meiosis
The type of cell division that produces gametes with half the number of chromosomes of the parent cell
Mitosis
The type of cell division that produces two daughter cells identical to the parent cell
Replication
The process of making copies of DNA
Sex chromosomes
The chromosomes that determine the sex of an individual; in humans they are X and Y chromosomes.
XX- female
XY- male
Homologous chromosomes
Chromosomes with genes for particular characteristics at the same location
Alleles
Different forms of the same gene
Dominant
The characteristic that is expressed in the homozygous condition
Recessive
The characteristic that remains hidden in the homozygous condition
Genotype
Genetic information carried on by an individual
Heterozygous/hybrid
Having two different alleles on homologous chromosomes
Homozygous/pure breeding
Having two identical alleles on homologous chromosomes
Phenotype
Observable characteristics of the individual; the way the genotype is expressed
Pure breeding
he same genetic information for a characteristic is passed down generation after generation
Chromosomes
Thread-like structures in the nucleus. Composed of DNA and proteins; contains the genetic information in the form of genes
DNA determines what
A Molecule that determines genetic characteristics of most living things
