Genetics Flashcards Preview

HSCI100 > Genetics > Flashcards

Flashcards in Genetics Deck (20):
1

gene

DNA segment located on a specific chromosome site containing info for specific protein production (polypeptide)

2

allele

alternative form of gene
- pair
- one from each parent

3

genotype

specific alleles related to a particular (set of) trait(s) (phenotypes)

4

polymorphism

used to indicate different versions of genes

5

homozygous

2 copies of same allele

6

heterozygous

different alleles of a given gene

7

dominant allele

expressed, masks recessive gene (TT/Tt)

8

recessive allele

only expressed when there are 2 of this (tt)

9

phenotype

observable traits

10

law of segregation

gamete formation: 2 alleles/chromosome separate as homologous chromosomes move toward opposite ends of cell (meiosis)
- each chromosome inherited independent of other chromosomes

11

gregor mendel

- how single genes inherited from parent to offspring
- first used one-trait crosses
- two-trait (dihybrid) crosses

12

dominant alllele

produces a functional protein that recessive allele does not

13

albinism

ability to produce melanin is lacking
- recessive allele produces nonfunctional tyrosinase

14

codominance

effects of both alleles are apparent in a heterozygote
- eg blood type AB (A+B alleles_

15

incomplete dominance

- trait expression in heterozygous individual is in between of a homozygous dominant/recessive- eg sickle-cell

16

plieotropy

one gene resulting in many problems

eg: sickle cell anemia

17

polygenic inheritance

variation in a trait independent of environmental influences (involves 2(+) genes, often on different chromosomes)

- eg height

18

x/y-linked inheritance

allele carried on the X/Y chromosome

- most sex-linked are x-linked

19

x-linked disorders

most are recessive
- color blindness
- muscular dystrophy
- hemophilia

20

nondisjunction

- both members of a homologous pair go into same daughter cell during meiosis 1
- sister chromatids fails to separate in meiosis 2