Genetics Flashcards
what is a gene?
a sequence of nucleotides that provides a set of instructions for making a protein
True or False: each cell contains all genes but not all genes are expressed by each cell
TRUE
(taken from quiz)
what is a karyotype?
representation of each person’s unique set of chromosomes
what is a phenotype?
physical expression of a person’s genes
what is genetics?
the study of inheritance
what is an allele?
versions of each gene
fill in the blank: If an individual has 2 of the same allele, they are considered _______________ for this gene.
homogeneous (BB or bb)
(from the quiz)
fill in the blank: If an individual has 2 different variants of an allele, they are considered _______________ for this gene.
heterogenous (Bb)
(from the quiz)
what does it mean to have a dominant allele?
this allele is more powerful
what does it mean to have a recessive allele?
this allele is weaker when dominant alleles are present
TRUE or FALSE: offspring will express the recessive allele in heterozygous genes?
FALSE: offspring will always express the dominant allele if it present
what does congenital mean?
present at birth
what are some common congenital alterations?
(just know the names, will go in depth in the next slides)
-autosomal dominant
-autosomal recessive
-sex-linked disorders
-multifactorial disorders
-chromosomal disorders
describe autosomal dominant alteration
if one parent carries a single allele, the offspring will have 50% chance of inheriting the disorder
what is an example of autosomal dominant? explain what is it and what it looks like
Marfan Syndrome: a degenerative connective tissue disorder
-signs: long extremities, really tall, narrow face
-common examples: Abraham Lincoln
describe autosomal recessive:
single gene mutations passed on from 2 affected parents (carriers)
TRUE or FALSE: disease of autosomal recessive only occurs in homogenous pairs
TRUE: must be 2 of the same recessive allele
what is an example of autosomal recessive disease? explain what is it and what it looks like
Tay-Sachs Disease: mutation in gene that codes for lysosomal enzyme that breaks down certain lipids…can accumulate in nerve cells and eventually causes demyelination
describe sex linked disorders:
mutations in genes located on the sex chromosomes
TRUE or FALSE: females (XX) are more likely to be affected but males (XY) are more likely to be carriers
FALSE: females=more likely to be carriers and males=more likely to be affected
what is an example of a sex linked disease? explain what is it and what it looks like
-Fragile X syndrome: gene on X chromosome that plays a role in neuronal synapse development
signs and symptoms: Intellectual, behavioral and learning disabilities, hyperactivity and inattentiveness, seizures, and long narrow face w large ears, jax and forehead
describe multifactorial disorders:
results from an interaction between environmental and genetic factors
what is an example of a multifactorial disease? explain what is it and what it looks like
-cleft lip/palate: tissue of the roof of the mouth does not join together…is left open
-clubfoot: deformity of foot when it’s turned inward
-congenital heart defects
-urinary tract malfunctions
-psychiatric disorders
describe chromosomal disorders:
variation in chromosomal duplication (extra copy of a certain chromosome was made during development)
what is an example of a multifactorial disease? explain what is it and what it looks like
Trisomy 21 (Down Syndrome): spontanteous mutation of extra copy of Chromosome 21
signs and symptoms: Hypotonia, distinctive facial features, congenital heart defects, single hand crease, developmental delays, behavior and learning changes
