Chapter 3

Question 1

Gene

Answer 1

inherited factor (encoded in the DNA) that helps determine a characteristic

Question 2

Allele

Answer 2

1 of 2 or more alternative forms of a gene

Question 3

Locus

Answer 3

Specific place on a chromosome occupied by an allele

Question 4

Genotype

Answer 4

set of alleles possessed by an individual organism

Question 5

Heterozygote

Answer 5

An individual organism possessing two different alleles at a locus (homozygous is the same)

Question 6

Phenotype or trait

Answer 6

appearance of a characteristics (ex: brown/blue)

Question 7

Characteristic

Answer 7

Feature possessed by organism (ex: an eye color)

Question 8

monohybrid cross

Answer 8

parents differ only in one way

Question 9

First generation of cross

Answer 9

P generation

Question 10

offspring of parents

Answer 10

F1

Question 11

Reciprocal Crosses

Answer 11

in one cross, pollen (the male gamete) was taken from a plant with round seeds, and in its reciprocal cross, pollen was taken from a plant with wrinkled seeds. Reciprocal crosses gave the same result: all F1 seeds were round.

Question 12

Principle of segregation and independent assortment occur during

Answer 12

anaphase 1

Question 13

Principle of segregation

Answer 13

Each individual diploid organism possesses two alleles for any particular characteristic. Alleles separate when games form and separate in equal portions.

Question 14

Independent Assortment

Answer 14

alleles at different loci separate independently

Question 15

hermaphroditism/monecious

Answer 15

have both reproductive systems

Question 16

dioecious

Answer 16

female and male female reproductive systems in different people

Question 17

XX-XO system

Answer 17

XX female
XO male

Depends on type of male gamete. Sperm will either have X or not.

Question 18

How do X & Y chromosomes match up?

Answer 18

Pseudoautosomal regions at the end of chromosomes

Question 19

ZZ-ZW

Answer 19

Female is Heterogametic (ZW)

Male is ZZ

Question 20

Genic Sex determination

Answer 20

no distinct sex chromosomes. Sex determined by genes on undifferentiated chromosomes.

Question 21

Environmental sex determination

Ex: Sequential Hermaphroditism

Answer 21

Sex Determined by environmental factors
no heterogametic sex

Sequential Hermaphroditism: female and male pile on system

Question 22

Sex Determination in Drosophilia

Answer 22

X to autosomes

1. 3-1.5 Metafemale
2. 0 female
3. 67 intersex
4. 5 male
5. 33 metamale

Question 23

Turner Syndrome

Answer 23

1/3,000

Sterile

Question 24

Klinefelter

Answer 24

1/1,000
XXY, XXXY, XXXXY, XXYY
Taller, sterile, small testes, reduced facial/pubic hair

Question 25

Poly-X females

Answer 25

triple x syndrome

Question 26

XYY

Answer 26

males with extra Y. 1/1,000.

Question 27

Sex determining region Y (SRY)

Answer 27

Makes people males.

Question 28

Androgen insensitivity

Answer 28

no menstration