Chapter 2 - Genetics Flashcards
chromosome
threadlike structure of nucleic acids & protein, found in the nucleus of most living cells, carries the genetic information in the form of genes
Gene
unit of heredity that is transferred from parent to offspring & is held to determine some characteristic of the offspring.
deoxyribonucleic acid (DNA)
double helix staircase shape, self replicating material present in almost all living organisms as the main constituent of chromosomes, the carrier of genetic information,
karyotype
number & visual appearance of chromosomes in the cell nuclei of an organism or species
amniocentesis
sampling of amniotic fluid using a hollow needle inserted into the uterus to screen for developmental abnormalities in a fetus
autosomal cell
a chromosome that is not a sex chromosome (1-22)
homologous chromosome
chromosome pairs, one from each parents that are similar in length, Gene position, and centromere location
replicate
make an exact copy of; reproduce
Mitosis
cell division that results in 2 daughter cells each having the same number & kind of chromosomes as the parent nucleus, typical of ordinary tissue growth
diploid cells
a cell that contains 2 sets of chromosomes.
asexual reproduction
reproduction by which offspring arise from a single organism and inherit the genes of that parent only, it does not involve the fusion of gametes and almost never changes the number of chromosomes
Gamete
Sex cell , able to unite with with another from the opposite sex in sexual reproduction to form a zygote
Meiosis
type of cell reproduction resulting in 4 daughter cells with half the number of chromosomes of the parent cell, as the production of gametes and plant spores
crossing over
exchange of genes between homologous chromosomes resulting in a mixture of parental characteristics in offspring
haploid
a cell having a single set of unpaired chromosomes
selective breeding
aka artificial selection
process by which humans use animal breeding and plant breeding to selectively Develop particular phenotypic traits by choosing which typically animal and plant males and females will breed together and have offspring
acquired traits
physical characteristic of an organism that is not passed down to offspring genetically. it is not coded in the organism’s DNA & is a product of the environment’s influence on the organism
inherited traits
trait passed on from parent to offspring
alleles
1 or 2 or more alternative forms of a gene That arise by mutation & are found at the same place on a chromosome
dominant trait
a trait that will appear in the offspring if one of the parents contributes it
recessive trait
trait that can be carried in a person’s genes without appearing in that person.
Genotype
the genetic constitution of an individual organism
phenotype
set of observable characteristics of an individual resulting from the interaction of its genotype with the environment
punter square
diagram used to predict outcome of a particular cross or breeding experiment
Homozygous
when an individual has 2 of the same allele whether dominant or recessive.
RR or rr
Heterozygous
a pair of genes where one is dominant and one is recessive, they’re different
Rr
Sex linked inheritance
pattern of inheritance that may result from a mutant gene located on either the X chromosome or the Y chromosome
Autosomal inheritance
pattern of inheritance where one affected individual has one copy of a mutant gene and one normal gene on a pair of autosomal chromosomes (autosomal diseases require individual must have 2 copies of the mutant gene)
Nucleotide
compound consisting of a nucleoside linked to a phosphate group. nucleotides form basic structural unit of nucleic acids like DNA
base pair
pair of complimentary bases in a double stranded nucleic acid molecule consisting of purine in one strand linked to hydrogen bonds to a pyramidine in the other. cytosine pairs w guanine and adenine paired w thymine in DNA or RNA (uracil)
histone
any group of basic proteins found in chromatin
replication
action of copying or reproducing something.
amino acid
simple organic compound containing both carboxyl and an amino group
DNA triplet code
standard version of a genetic code, in which a sequence of 3 nucleotides on a DNA or RNA molecule codes for a specific amino acid in protein synthesis
Mutation
changin the structure of a gene resulting in variant form that may be transmitted to subsequent generations caused by the alteration of single base units in DNA or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes
point mutation
mutation affecting only 1 or few nucleotides in a gene sequence.
frame shift mutation
genetic mutation caused by insertions or deletions of a number of nucleotides in a DNA sequence that is not divisible by 3.
genetic disease
genetic problem caused by 1 or more abnormalities in the genome especially a condition present from birth (congenital)
carrier
person or organism that has inherited a recessive allele for a genetic trait or mutation but doesn’t display that trait or show symptoms of the disease
mutagen
an agent that causes genetic mutation
carcinogen
a substance capable of causing cancer in living cells
pedigree
recorded ancestry of an animal
transformation
genetic alteration of a cell resulting in different DNA codes
plasmid
a genetic structure in a cell that can replicate independently of the chromosomes
DNA fingerprint
technique used for identification (forensic purposes) by extracting and identifying the base-pair pattern by a person’s DNA
transgenics
an organism that contains genetic material into which DNA from an unrelated organism has been artificially introduced
genetic engineering
deliberate modification the characteristics of an organism by manipulating its genetic material
genetically modified organisms
GMO, an organism whose genetic material has been altered using a genetic engineering technique
bio weapons
living organisms or replicating entities (viruses ) that reproduce or replicate within their host victims
recombinant DNA
DNA that has been formed artificially by combining constituents from different organisms
gene therapy
transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.
