Ch 13 Meiosis Exam 3

Question 1

Homologous Chromosomes

Answer 1

-chromosomes that are the same size and shape

Question 2

Autosomes

Answer 2

-not associated with sex determination

Question 3

Sex Chromosomes

Answer 3

-determine an organism’s sex

Question 4

Allele

Answer 4

-differences in genes
-example: eye color

Question 5

Diploids

Answer 5

-two homologs of each chromosome
-example: the 2 in 2n

Question 6

Haploids

Answer 6

-one of each type of chromosome
-equals n

Question 7

Meiosis

Answer 7

-one round of DNA replication followed by two rounds of cellular division
-the back-to-back divisions are Meiosis I & Meiosis II

Question 8

Meiosis I

Answer 8

-reduces the number of chromosomes

Question 9

Meiosis II

Answer 9

-division is the same as in Mitosis

Question 10

Interphase in Meiosis

Answer 10

-pre-meiotic S-phase
-chromosomes replicate

Question 11

Prophase I in Meiosis

Answer 11

-homologs come together
-involves breaking and connecting together DNA

Question 12

Metaphase I in Meiosis

Answer 12

-kinetochore microtubules move bivalent pairs to metaphase plate
-each bivalent straddles the metaphase plate with one homolog on each side
-the alignment of each bivalent is independent of other bivalents

Question 13

Anaphase I & Telaphase I in Meiosis

Answer 13

-sister chromatids remain together
-cytokinesis results in reduction of chromosome numbers

Question 14

Meiosis I Description

Answer 14

-results in daughter cells that have one chromosome of each homologous pair
-daughter cells are haploid
-chromosomes in each cell randomly assorted due to crossing over and random distribution of maternal and paternal

Question 15

Mitosis v. Meiosis Differences

Answer 15

-homolog pairing in meiosis
-crossing over

Question 16

Meiosis Increases Diversity

Answer 16

-chromosomes in gamete differ from the parent cell

Question 17

Asexual Reproduction

Answer 17

-any mechanism of producing offspring that doesn’t involve gametes
-resulting daughter are genetically identical to mothers

Question 18

Sexual Reproduction

Answer 18

-production of offspring by mating and fusion of gametes
-offspring are genetically distinct from parent cells

Question 19

Chromosomes & Heredity

Answer 19

-in the body 23 homologous pairs of chromosomes
-46 chromosomes in total
-half from mom & half from dad
-each chromosome contains genes

Question 20

Law of Independent Assortment

Answer 20

-each gene will sort independently

Question 21

Genetic Recombination

Answer 21

-new combinations of alleles

Question 22

Crossing Over

Answer 22

-produces new combinations of alleles within a chromosome
-combined with independent assortment
-incredible amount of genetic diversity

Question 23

Self-Fertilization

Answer 23

-the offspring are genetically distinct from the parents

Question 24

Outcrossing

Answer 24

-when gametes from one individual combine with another

Question 25

Down Syndrome

Answer 25

-caused by trisomy of chromosome 21

Question 26

Nondisjunction

Answer 26

-when the sister chromatids do not separate
-results in aneuploidy

Question 27

Aneuploidy

Answer 27

-one cell has the incorrect number of chromosomes after meiosis and fertilization

Question 28

Paradox of Sexual Reproduction

Answer 28

-need one member of each sex to produce progeny
-only females can produce progeny
-results in less individuals over time