Unit 1: Genetics

Question 1

Chromosome

Answer 1

-DNA
-Occurs in pairs
Humans: 23 pairs

Question 2

Autosomal Set

Answer 2

Combination of chromosomes
-One each of Homologous pair
-We are diploid species
Non-sex chromosomes

Question 3

Karyotype

Answer 3

• Genetic study matching chromosome pairs

- Gives your chromosomal patterns: Looks for chromosome abnormalities

Question 4

Genes

Answer 4

Carry traits
-Height, hair type
Located on certain positions of certain chromosomes
-Human Genome study

Question 5

Genotype

Answer 5

Genetic composition

Question 6

Phenotype

Answer 6

Your external appearance

Question 7

Dominant Gene

Answer 7

One gene is expressed over the other

Question 8

Recessive gene

Answer 8

A gene that is usually hidden (unless it is

homozygous recessive

Question 9

Homozygous

Answer 9

Both genes are either dominant or recessive

Question 10

Heterozygous

Answer 10

Each gene is different

Question 11

Patterns of Inheritance

Answer 11

-Important for genetic counseling
-Most severe anomalies do not survive: 90% spontaneously aborted
?? Earlier abortion occurs = more
chromosomal problems

Question 12

Punnett Square

Answer 12

Upper Case letter = Dominant

Lower Case letter = Recessive

Question 13

Both parents are homozygous:

Answer 13

Dominant

Question 14

Both parents are homozygous

Answer 14

Recessive

Question 15

Both parents are heterozygous

Answer 15

.

Question 16

Sex-Linked

Answer 16

.

Question 17

Autosomal Recessive

Answer 17

• Effect of gene is NOT present if only one parent carries the trait
• ONLY present if BOTH parents have the trait: Generations often skipped, Pretty equal between gender
• Problems most common in consanguineous marriages
• BOTH parents have the trait = all children will have trait
• Examples: PKU, glactosemia, homocysturia, Maple-Syrup Disease, SMA, Cystic Fibrosis

Question 18

Autosomal Recessive: Both parents are carriers

Answer 18

1:4 chance that children WILL have trait

Question 19

Autosomal Recessive: Both parents have condition

Answer 19

100% will have trait

Question 20

Autosomal Dominant

Answer 20

• Effect of gene is apparent if 1 parent has the gene
• Should not skip generations
• Affected married to a normal = 50% affected, 50% normal
• Pretty equal between gender
• Ex: Marfan’s Syndrome, Neurofibromotosis, Huntington’s Disease, glaucoma, polydactyly