Genetics Basic Info

Question 1

Hereditary units of DNA transmitted from one generation to another that code for proteins

Answer 1

genes

Question 2

The specific location of a gene on a chromosome

Answer 2

locus

Question 3

Different versions of a gene; humans have 2 for each autosomal gene

Answer 3

alleles

Question 4

Chromosomes that have the same genes at the same loci, one maternal and one paternal

Answer 4

Homologous chromosomes

Question 5

The genetic information contained in the cells, on the chromosomes, for a particular species

Answer 5

genome

Question 6

Any chromosome that is not a sex chromosome; we have 22 of them

Answer 6

autosome

Question 7

How many pairs of allosome chromosomes do humans have?

Answer 7

1 (sex chromosome pair, XX or XY)

Question 8

The number of chromosomes in sex cells/gametes (n=23)

Answer 8

haploid number (n)

Question 9

The total number of chromosomes in somatic cells (2n=46)

Answer 9

diploid number (2n)

Question 10

Short arm is the _ arm.

Long arm is the _ arm.

Answer 10

short arm = p

long arm = q

Question 11

In what sorting order are chromosomes numbered?

Answer 11

Longest to shortest, except for sex chromosomes

Question 12

All of the alleles of an organism

Answer 12

genotype

Question 13

A measurable trait an organism has

Answer 13

phenotype

Question 14

How many genotypes and phenotypes are listed below for albinism:
AA, Aa, aa
Pigmented, pigmented, albino.

Answer 14

3 genotypes

2 phenotypes

Question 15

When two alleles for a trait are equally expressed

Answer 15

Codominance

ex. AB blood type

Question 16

When heterozygotes have phenotypes that have both alleles visible as a blend (one isn’t expressed over the other)

Answer 16

incomplete dominance 
(ex. wavy hair)

Question 17

The probability that individuals in a population who have a particular gene combination will show the condition

Answer 17

penetrance

ex. if a mutation causing diabetes has a 95% penetrance, 95% of the people with the mutation will develop diabetes

Question 18

The components of the phenotype that are exhibited in an individual

Answer 18

expression

two people with MD showing different symptoms

Question 19

Genetic diseases that increase in severity or have earlier onset with each successive generation

Answer 19

anticipation

ex. Huntington’s dx

Question 20

Two types of chromosomal abnormalities

Answer 20

Numerical

Structural

Question 21

Most common type of chromosomal abnormality

Answer 21

aneuploidy (abnormal number, i.e. 45 or 47)

Question 22

The rupture of a chromosome resulting in the pieces “re-sticking” in the wrong combinations

Answer 22

Balanced translocation

Question 23

When a chromosome piece is lifted out, turned around, and reinserted

Answer 23

Inversion

Question 24

Types of unbalanced chromosomal abnormalities

Answer 24

Deletion

Insertion

Question 25

What translocation tends to arise as an offspring of a balanced carrier?

Answer 25

Unbalanced translocation

Question 26

Robertsonian translocation

Answer 26

- involves any 2 of: chromosomes 13, 14, 15, 21, 22 - Results in formation of a "new" chromosome - Bigger chromosome produces an unbalanced gamete

Question 27

Pedigree symbol: | Male

Answer 27

Square

Question 28

Pedigree symbol: | Female

Answer 28

Circle

Question 29

Pedigree symbol: | Diagonal line through symbol

Answer 29

Deceased

Question 30

Pedigree symbol: | Shaded symbol

Answer 30

Affected with trait

Question 31

Pedigree symbol: | Half-shaded symbol

Answer 31

Carrier of trait

Question 32

Pedigree symbol: | Horizontal line

Answer 32

Siblings

Question 33

Pedigree symbol: | Line of descent

Answer 33

Offspring

Question 34

Pedigree symbol: | Two hash marks

Answer 34

Divorced/Separated

Question 35

Pedigree: | The person seeking genetic advice (represented by an arrow)

Answer 35

Consultand

Question 36

Pedigree: | The affected individual(s)

Answer 36

Proband

Question 37

Pattern of inheritance where a mutation in a single allele can cause disease

Answer 37

Autosomal dominant | ex: Huntington's disease (HH, Hh affected)

Question 38

Pattern of inheritance where 2 copies of the diseased allele are required for expressing the phenotype

Answer 38

Autosomal recessive | ex. Cystic fibrosis

Question 39

Pattern of inheritance where the mutant allele is located on the X chromosome

Answer 39

X-linked | ex. Muscular dystrophy, Fragile X syndrome

Question 40

What is more likely: sporadic or inherited cancer syndrome?

Answer 40

sporadic cancer