GENETICS Flashcards
GENETICS
the study of heredity and variation in living organisms
HOW HEREDITARY CHARACTERISTICS ARE TRANSFERRED
by gametes through the fusion of the male and female gametes
GENOME
the complete set of genes of a particular organism / it is a copy of all the essential DNA coding required to synthesize all the proteins the organism needs
MENDEL’S LAW OF DOMINANCE
if two alleles are different, only the dominant one will be expressed
GENOTYPE
the composition of the gene pair for a specific trait
PHENOTYPE
the observable physical characteristic
HOMOZYGOUS
when the two alleles are the same (TT, tt)
HETEROZYGOUS
when the two alleles are diff (Tt)
MENDEL’S LAW OF SEGREGATION
during meiosis, homologous chromsomes pairs seperate. thus each gamete that is produced receives only one allele of a gene pair.
MONOHYBRID CROSSES
a cross where only one hereditary characteristic is investigated at a time
P1 GENERATION
the two parents that are originally crossed
WHEN DO THE TWO CHROMOSOMES OF THE HOM PAIR SEPERATE
during Anaphse I
F1 GENERATION
the first gen offspring
COMPLETE DOMINANCE
when only the dominant allele is observed
INCOMPLETE DOMINANCE
when two homo individuals are crossed and the offspring’s phenotype expresses an intermediate form of the two rents’ characteristics (neither allele is dominant)
(diff letters are used for each charact)
CO-DOMINANCE
when both characteristics are visible when both alleles of the gene pair are equally dominant
BLOOD GROUPS
A - IᴬIᴬ or Iᴬi
B - IᴮIᴮ or Iᴮi
AB - IᴬIᴮ
O - ii
DIHYBRID CROSSES
where two pairs of contrasting characteristics, carried on diff homologous pairs, are crossed
MENDEL’S LAW OF INDEPENDENT ASSORTMENT
The alleles of different genes get sorted into gametes independently of one another.
AUTOSOMES
the 22 chromosome pairs with similar shape of the 23 that humans have
GONOSOMES
aka sex chromosomes
are the 23rd pair which is responsible for sex determination
SEX CHROMOSOMES
XX - female
XY - male
SEX-LINKED GENES
X chromosome, which is larger and can carry many other genes
MUTATIONS
a change in the genetic composition of an organism
GENE MUTATIONS
this occurs as a result in a change in the nucleotide sequence in the DNA molecule
WHEN DO GENE MUT OCCUR
- DNA replication
- transcription of DNA to mRNA
- crossing over during Metaphase I
TYPES OF GENE MUTATIONS
- substitution
- inversion
- deletion
- insertion
SUBSTITUTION
a gene mutation where one nit base is replaced by another (only one amino acid is altered)
INVERSION
a gene mutation where one or more base triplets are inverted
DELETION
a gene mutation where one or more nit bases are lost and may result in a frame shift. after this all the base triplets are altered
INSERTION
a gene mutation where one or more nit bases are inserted as a result of a frame shift
HARMLESS GENE MUTATIONS
mutations in the non-coding DNA and do not affect the synthesis of proteins; may be passed on to future generations
HARMFUL GENE MUTATIONS
cause genetic disorders and are autosomal recessive
eg.) albinism, sickle cell anaemia
GENETIC PEDIGREES/LINEAGES
the inheritance of characteristics in families over several gens
HAEMOPHILIA
blood does not clot
Sufferers can bleed to death if injured
COLOR BLINDLESS
Sufferers cannot distinguish colours properly
E.g. red from green, blue from yellow
DNA TESTING
the process whereby medical tests are used to identify changes in chromo and genes / trace changes associated w hereditary disorders
GENETIC COUNSELLING
takes place after genetic testing has confirmed the occurrence or risk of a genetic disorder
mtDNA
- occurs in the mitochondria and is circle
- much shorter than chromosomal DNA
GENETIC ENGINEERING
- the direct manipulation of genes in an organism to obtain a desired characteristic
- can also replace faulty or missing genes that cause issues
TRANSGENIC ORGANISM
the organism receiving the gene
GMOs
- genetically modified organisms
- utilized in a variety of human activities to improve quality of life or productivity
IMPORTANCE OF GMOs and GEN ENG
plays a role in:
- synthesis of medical drugs
- cloning
- stem cell research
- insulin production in medicine
- vaccine production
ADV OF GMOS
- larger better yields and stronger crops
- cheaper for farmers
- inc shelf life
DISADV OF GMOS
- can cause allergies in humans
- decreases biodiversity
- can become unaffordably expensive
BIOTECHNOLOGY
a field of study that uses living organisms and their biological processes to develop technology
eg.) producing vaccines, biofuels, antibiotics, improving crop productivity
CLONING
the process in which a genetically identical replica of something is created
REPRODUCTIVE CLONING
the technique used to produce an animal w the same DNA as another animal
STEM CELL RESEARCH
studies which help to find a better quality of life to people with brain or spinal injuries
STEM CELLS
- simple, undifferentiated somatic cells
- not specialized
- come from inner cell mass of embryo, foetus from terminated pregnancy
USE OF STEM CELLS
treating spinal injuries
replacing damaged tissues
ADULT STEM CELLS
differentiate to replace and repaired damaged or diseased tissue of the same type
HOW ADULT STEM CELLS ARE OBTAINED
obtained from bone marrow, brain, blood
MULTIPOTENT CELLS
differentiate into a limited number of related tissues
THREE TYPES OF CLONING
DNA, reprodcutive, therapeutic
DNA CLONING
transfer of a DNA segment fromone organism to a self-replicating structure
THERAPEUTIC CLOTHING
embryo cloning
produced for research purposes
viewpoints against cloning
unnatural
decreases genetic variation
harmful genes may be transferred to other gens
viewpoints for cloning
- may provide hope for couples who can’t have children
- may eliminate diseases
- imp food prod
VECTOR
an organism that transfers something
RECOMBINANT DNA
the formation of a new DNA sequence in the recipient cell
ALLELES
alternative forms of the same gene
multiple alleles
when a gene has more than two possible alleles to control a hereditary characteristic
polygenic characteristics
a hereditary characteristic controlled by more than one gene pair at different loci
