Genetics

Question 1

what is a gene?

Answer 1

a sequence of nucleotides that provides a set of instructions for making a protein

Question 2

True or False: each cell contains all genes but not all genes are expressed by each cell

Answer 2

TRUE
(taken from quiz)

Question 3

what is a karyotype?

Answer 3

representation of each person’s unique set of chromosomes

Question 4

what is a phenotype?

Answer 4

physical expression of a person’s genes

Question 5

what is genetics?

Answer 5

the study of inheritance

Question 6

what is an allele?

Answer 6

versions of each gene

Question 7

fill in the blank: If an individual has 2 of the same allele, they are considered _______________ for this gene.

Answer 7

homogeneous (BB or bb)
(from the quiz)

Question 8

fill in the blank: If an individual has 2 different variants of an allele, they are considered _______________ for this gene.

Answer 8

heterogenous (Bb)
(from the quiz)

Question 9

what does it mean to have a dominant allele?

Answer 9

this allele is more powerful

Question 10

what does it mean to have a recessive allele?

Answer 10

this allele is weaker when dominant alleles are present

Question 11

TRUE or FALSE: offspring will express the recessive allele in heterozygous genes?

Answer 11

FALSE: offspring will always express the dominant allele if it present

Question 12

what does congenital mean?

Answer 12

present at birth

Question 13

what are some common congenital alterations?

(just know the names, will go in depth in the next slides)

Answer 13

-autosomal dominant

-autosomal recessive

-sex-linked disorders

-multifactorial disorders

-chromosomal disorders

Question 14

describe autosomal dominant alteration

Answer 14

if one parent carries a single allele, the offspring will have 50% chance of inheriting the disorder

Question 15

what is an example of autosomal dominant? explain what is it and what it looks like

Answer 15

Marfan Syndrome: a degenerative connective tissue disorder

-signs: long extremities, really tall, narrow face
-common examples: Abraham Lincoln

Question 16

describe autosomal recessive:

Answer 16

single gene mutations passed on from 2 affected parents (carriers)

Question 17

TRUE or FALSE: disease of autosomal recessive only occurs in homogenous pairs

Answer 17

TRUE: must be 2 of the same recessive allele

Question 18

what is an example of autosomal recessive disease? explain what is it and what it looks like

Answer 18

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

Question 19

describe sex linked disorders:

Answer 19

mutations in genes located on the sex chromosomes

Question 20

TRUE or FALSE: females (XX) are more likely to be affected but males (XY) are more likely to be carriers

Answer 20

FALSE: females=more likely to be carriers and males=more likely to be affected

Question 21

what is an example of a sex linked disease? explain what is it and what it looks like

Answer 21

-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

Question 22

describe multifactorial disorders:

Answer 22

results from an interaction between environmental and genetic factors

Question 23

what is an example of a multifactorial disease? explain what is it and what it looks like

Answer 23

-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

Question 24

describe chromosomal disorders:

Answer 24

variation in chromosomal duplication (extra copy of a certain chromosome was made during development)

Question 25

what is an example of a multifactorial disease? explain what is it and what it looks like

Answer 25

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