Lecture 13/14- Genetics Flashcards Preview

HESP 632 - Medical Audiology > Lecture 13/14- Genetics > Flashcards

Flashcards in Lecture 13/14- Genetics Deck (84)
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1

What is Konigsmark's Classification of genetic hearing loss?

• No associated abnormalities
• External ear abnormalities
• Eye disease
• Musculoskeletal disease
• Integumentary system disease (Skin, hair, and nails)
• Renal disease (Kidney)
• Nervous system disease
• Metabolic and other abnormalities

2

What are the 2 universal principles of human genetics?

• Virtually all diseases (except some cases of trauma) have a genetic component
• There are no perfect human specimens – all of us carry a significant number of DNA glitches

3

What is a genome?

Complete set of genetic information
o Contains all of the biological information needed to build and maintain the organism
o Comprised of all of the organisms’ DNA
o Nuclear DNA
o Mitochondrial DNA (mtDNA)

4

What is an exome?

Protein coding portion of DNA
 Proteins are the output of the DNA

o Corresponds to mature RNA
o ~1% of total genome
o Composed of ~180,000 exons
o Mutations in exome harbor ~85% disease causing mutations

5

What is non-coding DNA?

o Intron- non-coding sections of a gene
o Important biologic functions

6

What are nucleotides?

Nitrogen containing base
 A and G are purines
 T and C are prymidines

Bound together through sugars and phosphate

7

How is DNA structured?

- Nucleotides
- DNA bases form pairs (A and T, C and G)
- Nucleotides strand forms a spiral (double helix)
- Sequence AACGTAATTTC

8

What are amino acids?

Building blocks of proteins
o Amino acids are sequenced- linked to form proteins
o Order of amino acids dictates protein shape and function
o Proteins- critical roles in the body

9

What are antibodies?

Bind to foreign particles- protective function

10

What are enzymes?

Carry out almost all of the chemical reactions in cells

11

What are messengers?

Transmit signals to coordinate biological processes between cells, tissues, organs

12

What are structural components?

Provide structure and support for cells, allow movement

13

What are transport and storage?

Bind and carry atoms and small molecules within cells and throughout the body

14

What is a mutation?

Change in a gene’s biochemical makeup, change at the DNA level

15

What is a mutagen?

A substance that causes a mutation
o Examples: radiation, aflatoxin B (fungus on peanuts), cola, tea, coffee, food additives, cigarette smoke, etc.

16

What is a mutant?

An allele that differs from the wild type allele, altering the phenotype
o Wild type: normal variant of a gene

17

What is a spontaneous mutation?

A genetic change resulting from the mispairing of bases during replications

18

What is a mutational hot spot?

Most likely to happen when the nearby DNA is repetitive

19

What is a point mutation?

Involving a single nucleotide in the DNA molecule

20

What is a missense mutation?

Change in a codon so that it codes for a different amino acid

21

What is a nonsense mutation?

Changes a codon specifying an amino acid into a “stop” codon (UAA, UAG, UGA)- results in a shortened protein produce

22

What is a deletion and insertion?

Involving >1 nucleotide
o Codon deletions and inserts involving bases which are a multiple of 3 resulting in a “frame” mutation
o Expansion of a tri-nucleotide repeat

23

What is a frameshift mutation?

Additional or deletion of bases that are not a multiple of 3 with disruption of the reading frame of the protein

24

What are structural chromosomal abnormalities?

Telomeres: protects chromosome
• Will shorten with aging process
• Dysfunction is associated with some diseases

Centromere: involved in cell division and replication of cells

P arm (short arm)

Q arm (long arm)

Bands: specific address of a gene

25

What are the number of chromosomes?

46 chromosomes, 23 homologous pairs
• 22 pairs are autosomes (the same regardless of sex)
• 1 pair of sex chromosomes

Biologically female: XX

Biologically male: XY

26

What is aneuploidy?

One or more extra or missing chromosomes

27

What is a translocation?

Change of location.

- In genetics this typically refers to transfer of a segment of a chromosome to a new position, most often on another chromosome

28

What is a deletion?

Loss of genetic material, ranging from a single nucleotide to an entire pice of chromosome

29

What is an inversion?

Same genetic material, but it is flipped

30

What are characteristics of autosomal dominant traits?

• Only one copy of gene to product phenotype
• Chance of recurrence is ½
• Vertical family pattern
• Persons with the trait have a parent with the trait, unless they represent a new mutation
• If line broken, stays broken
• Male: female= 1:1