Unit 3- Basic Principles of Heredity

Question 1

gene

Answer 1

an inherited factor (encoded in DNA) that determines characterstics

Question 2

allele

Answer 2

1 of 2 or more alternate form of gene

Question 3

locus

Answer 3

specific place on chromosome occupied by allele

Question 4

genotype

Answer 4

set of alleles possessed by indiv

Question 5

heterozygous

Answer 5

indiv with 2 diff alleles at locus

Question 6

homozygous

Answer 6

indiv with same 2 alleles at locus

Question 7

phenotype/trait

Answer 7

appearance of characteristic

Question 8

characteristic/character

Answer 8

attribute or feature possessed by organism

Question 9

monohybrid cross

Answer 9

cross between 2 parents that differ in a single characteristic

Question 10

Mendel conclusions from monohybrid cross

Answer 10

1. a character is encoded by 2 genetic factors
2. 2 genetic factors (alleles) seperate when gametes are formed
3. dom and recessive traits
4. 2 alleles sep with equal probability into gametes

Question 11

Principle of Segregation

Answer 11

each indiv diploid organism possesses 2 alleles for any trait. These 2 alleles separate when gametes form (1 in each gamete)

Question 12

Sutton

Answer 12

chromosomal theory of heredity

Question 13

probability

Answer 13

the likelihood of the occurrence of a particular event

Question 14

Multiplication Rule

Answer 14

aka “AND” rule

Question 15

Addition Rule

Answer 15

aka “OR” rule

Question 16

dihybrid crosses

Answer 16

• examine 2 traits at a time
• principle of Independent Assortment
  (foil out traits so RrYy = RY, Ry, rY, ry and multiply or do two seperate punnett squares and multiply.)
  (*9:3:3:1)

Question 17

Chi-square goodness of fit

Answer 17

the probability that the diff between the observed and expected value is due to chance
sum of (O-E)^2 / E

Question 18

hermaphroditism

Answer 18

both sexes in same organism

Question 19

monoecious

Answer 19

BOTH male and female reproductive structures in same organism

Question 20

diaecious

Answer 20

EITHER male or female reproductive structures in 1 organism

Question 21

XX-XO system

Answer 21

XX: female
XO: male
- ex: grasshoppers

Question 22

XX-XY system

Answer 22

XX: female
XY: male
- ex: mammals

Question 23

ZZ-ZW system

Answer 23

ZZ: male
ZX: female
- ex: birds, snakes, butterflies, some amphibian, and fish

Question 24

Haplodiploidy System

Answer 24

haploid set: male
diploid set: female
- ex: bees, wasps, and ants

Question 25

genic sex-determining system

Answer 25

no sex chromosomes, only the sex-determining genes
- ex: some plants, fungi, protozoans, and fish

Question 26

examples of environmental sex determination

Answer 26

Limper’s position in the stack and temperature in turtles

Question 27

sex determination in fruit fly

Answer 27

• genic balance system
• X:A ratio (x= # of x chromosomes; A= # of haploid sets of autosomes)
  0-0.5: metamale
  0.5: male
  0.5-1: intersex
  1: female
  1-1.5: metamale
  1.5: metafemale

Question 28

what determines maleness?

Answer 28

SRY gene of y chromosome
- y chromosome lost DNA over time

Question 29

Turner Syndrome

Answer 29

XO, 1/3000 females

Question 30

Klinefelter syndrome

Answer 30

XXY or XXXY or XXXXY or XXYY; 1/1000 males

Question 31

poly-x females

Answer 31

1/1000 females

Question 32

dosage compensation

Answer 32

the amount of protein produced by x-linked genes and randomly inactivated in 2 sexes

Question 33

barr body

Answer 33

the inactivated x chromosomes (any after the first one)