genetics Flashcards
how many chromosomes are in humans?
46
how many pair of autosomes?
22
which chemical compound contains the genetic instructions needed to develop and direct the action of every organism?
DNA- deoxyribonucleic acid
how many twisting strands make up the DNA?
two
the twisting strands of the DNA are made up of which three chemicals?
phosphoric acid (P)
deoxyribose (S)
paired nucleotide bases
-adenine to thymine
- guanine to cytosine
which chemicals are the backbone of the DNA twisting strands?
deoxyribose and the paired nucleotide bases
what do the backbone of the DNA strands do?
provide structural support
what do you call the compound that directs the synthesis of protein?
RNA-ribonucleic acid
where is DNA located?
nucleus
where does protein synthesis occur?
cytoplasm
what does mRNA do
-carries genetic code from nucleus to cytoplasm
-directs the formation of protein
what does tRNA do
-transports specific amino acids to ribosomes for protein synthesis on the ribosomes
what does rRNA do
-actually makes the protein
the process where the genetic code is transferred to messenger RNA
transcription
the process where protein is formed under the direction of mRNA
translation
two corresponding genes, and can be either dominant or recessive,
allele
actual DNA genetic make up
genotype
ex: gene for red hair
outward physical representation of gene
phenotype
normal genes that control cell growth
proto-oncogenes
abnormal genes that control cell growth and cell mitosis
oncogenes
genetic variant (defect)
mutation
proportion of individuals carrying a particular variant of a gene that express an associated trait
aka portion of people with the mutation who show the disease
penetrance
ex: 95% penetrance with mutation will develop disease, 5% will not
genetic variant with population frequency > 1%
polymorphism
ex: CYP450 enzymes in liver
-in charge for most of the phase 1 drug metabolism in liver
-polymorphisms can cause changes in drug metabolism (poor metabolizers to ultra rapid metabolizers)
-drug metabolism changes fat solubles to water soluble (hydrophillic)
most common type of genetic variation in humans that primarily effects gene quality
single nucleotide polymorphism (SNPs or snips)
ex: sickle cell
an organism’s complete set of DNA that lies within the 23 pairs of chromosomes within the nucleus of all cells
genome
how the exact order of the base pairs in DNA are made
genomic sequencing
dominant alleles are heterozygous or homozygous?
heterozygous
recessive alleles are heterozygous or homozygous?
homozygous
the single-gene diseases?
autosomal dominant
autosomal recessive
x-linked dominant
x-linked recessive
disease where an abnormal gene from one parent can cause the disease, even though the matching gene from the other parent is normal because the abnormal gene dominates
autosomal dominant
-each child has a 50% risk of inheriting the disorder
-half of the children will be heterozygous and express the disease
neurofibromatosis
marfan’s syndrome
malignant hyperthermia
huntington’s disease
achondroplasia
are all types of what genetic inheritance
autosomal dominant
when a parent carries one recessive gene but is not affected by the condition?
carriers/heterozygotes
the child who inherits both abnormal gene copies from parents
homozygote
when child receives two copies of defective gene
autosomal recessive inheritance
sickle cell disease
cystic fibrosis
phenylketonuria
are all examples of what type of inheritance
autosomal recessive disorders
gene causing the trait located on the X chromosome
x-linked recessive
red-green colorblindness
hemophilia A
Hemophilia B or Christmas Disease
Duschenne and Becker’s muscular dystrophy
Glucose-6-phosphate dehllydrogenase deficiency
are all examples of which type of disorder
x-linked recessive
process where protein is formed under the direction of mRNA
translation
