Genetics

Question 1

Gene

Answer 1

Segments of DNA on a chromosome

Question 2

Chromatid

Answer 2

One of two identical copies of a chromosome

Question 3

Sister chromatids

Answer 3

two identical chromosomes

Question 4

Centromere

Answer 4

Connects sister chromatids (at center)

Question 5

Telomere

Answer 5

ends of chromosome, important for stability

Question 6

Genotype

Answer 6

An organism’s genetic makeup

Question 7

Phenotype

Answer 7

The physical appearance of the genotype

Question 8

Non-Mendelian Inheritence

Answer 8

Inheritance pattern that does not follow Mendelian genetics (Codominance, incomplete dominance)

Question 9

Human somatic cells

Answer 9

• Diploid

- 200 different types

Question 10

Germline cells

Answer 10

reproductive cells

Question 11

Haploid cells

Answer 11

Cell with a single set of chromosomes

Question 12

Diploid cells

Answer 12

Cell with two sets of chromosomes

Question 13

Allele

Answer 13

A variant form of a given gene

Question 14

Autosome

Answer 14

Chromosome common in both genders

i.e. one from each parent

Question 15

Karyotype

Answer 15

• The entire set of a person’s chromosomes

- In a picture, shown ad single condensed, or as a duplicated chromosome

Question 16

Lyonization

Answer 16

• aka X-inactivation

- When an X chromosome in females is inactivated — gene “turned off”

Question 17

Mosaicism

Answer 17

Two or more types of cells with different genotypes in one individual (i.e. Down syndrome, Klinefelter syndrome, Turner syndrome) — more than one genotype from same fertilized egg

Question 18

Embryonic stem cells

Answer 18

• Cells with the potential to grow into many types of specialized cells
• Pluripotent

Question 19

Adult Stem Cells

Answer 19

-Can only generate cells types in accordance with the tissues they reside

Question 20

Modes of Inheritance

Answer 20

1) Autosomal Dominant
2) Autosomal Recessive
3) X-Linked Recessive
4) Y-Linked Recessive

Question 21

Autosomal Dominant

Answer 21

• 1 gene needed for expression
• Affected offspring has one affected parent
• Trait in every generation
• Each individual has a 50% chance of inheriting the trait

Question 22

Autosomal Recessive

Answer 22

• 2 copies of gene need to influence phenotype
• 1 allele present = carrier
• Two carries reproduce — 25% of being unaffected, 25% being affected, 50% unaffected carrier

Question 23

Mitochondrial DNA (mtDNA)

Answer 23

• Encodes a variety of proteins for OxPhos
• No introns present
• Maternal inheritance
• Mutation rate = 10x higher than nDNA
  - Lack of repair mechanisms

Question 24

Somatic cell mitosis (products)

Answer 24

Two genetically identical daughter cells

Question 25

Meiosis

Answer 25

• Division of germ cell twice with one round of DNA replication for the purposes of sexual reproduction
• Each daughter cell is haploid (reduces chromosomes by half) and genetically dissimilar
• Males: sperm
• Females: one egg and three polar bodies

Question 26

Homologous recombination

Answer 26

DNA crossover event between homologous chromosomes during meiosis, resulting in genetic variation in the daughter cells —- NEW COMBINATIONS OF GENES

Question 27

Ways to create genetic diversity in Meiosis

Answer 27

1) Homologous recombination

2) Random homolog segregation

Question 28

Errors of Meiosis

Answer 28

1) Polyploidy – cells contain extra set of chromosomes

2) Aneuploidy – cells contain and missing of additional individual chromosome (i.e trisomy 21)

Question 29

Nondisjunction

Answer 29

Failure of sister chromatids to separate normally during division, resulting in uneven chromosome distribution amongst daughter cells