Meiosis And Sexual Life Cycles Ch.13

Front 1

Genes

Back 1

Coded information in DNA that can be used to build an Organism

Front 2

Gametes

Back 2

Reprocutive Cells that transmit genes from one generation to the next

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Locus

Back 3

A Gene's specific location along the lengh of a chromosome

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Asexual Reproduction

Back 4

-One sole individual passes copies of all it'sgenes to It's offspring
-Mitosis
-exact copies of parent (clones)

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Sexual Reproduction

Back 5

-Two parents give they genes to their offspring, and each offspring has different combinations of genes inhereted by the two parents
-Meiosis
-genetically different

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Somatic Cell

Back 6

any other cell besides a gamete

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Karyotype

Back 7

The order in which chromosomes are put in, longest to smallest and are all in pairs

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Homologous Chromosomes (homologues)

Back 8

two chromosomes with the same lengh, centromere position, and staining pattern

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Sex Chromosomes and Autosomes

Back 9

-X and Y Chromosomes: determine an individuals sex

-all other Chromosomes

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Diploid Cell

Back 10

A cell containing two chromosome sets
(single set represented by n, diploid is 2n)

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Haploid Cells

Back 11

gamete cell that just has one chromosome set
(single set represented by n, haploid cell is n)

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Fertiliation (Human life cycle)

Back 12

the union of two gametes (egg and sperm) causes the fusion of their nuclei

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Zygote

Back 13

A fertilized egg, it contains a diploid set of chromosomes

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Meiosis

Back 14

A type of cell division that reduces the number of chromsomes into a haploid set so that a diploid set doesn't double

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alternation of generations

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A life cycle that includes both diploid and haploid multicellular stages.
(first generation produces a sporophyte, then the next generation is a gametophyte, and then switches between the two every generation)

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Sporophyte

Back 16

the multicellular diploid stage in alternation of generations
-meiosis in this stage creates haploid cells called spores

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Spore

Back 17

a Haploid cell created in the sporophyte stage of meiosis, and they can give rise to multicellular individuals without fusing with another cell

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Gametophyte

Back 18

a multicellular haploid stage created by a spore dividing mitotically

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Meiosis I

Back 19

first division of meiosis

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Meiosis II

Back 20

second division of Meiosis

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Interphase (Meiosis)

Back 21

-Chromosomes are replicated but remained uncondensed
-the Centrosome replicates

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Prophase I

Back 22

-longest phase of meiosis
-Chromosomes begin to condense homologues loosley pair along their lenghs, ligned by gene
-Crossing over and synapsis occurs along the chromosomes

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Metaphase I

Back 23

-Homologues align on the metaphse plate
-Chthromatids are connected to kinetochore microtubules from each poles

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Anaphase I

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-homologues move towards opposite poles
-sister chromotids stay attached at the centromere

Front 25

Telophase II and cytokinesis

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-two daughter cells form and the cytoplasm is divided simultaneously
-in some species the chromosomes decondense and the nuclear envelope and nucleoli re-form

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Prophase II

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-Spindle forms
-chromosomes still composed of two sister chromatids

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Metaphase II

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-Chromosomes on Metaphase plate
-chromosomes not genetically identical
-Kinetichores of spindle attach to the chromosomes

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Anaphase II

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-Centromeres of each chromosome finally seperate, and sister chromatides come a part
-sister chromosomes move towards opposite poles

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Telophase II and Cytokinesis

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-Nuclei and nuclear envelope forms
-four daughter cells are formed
-each daughter cell genetically distinct

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Synapsis

Back 30

when chromosomes become physically connectedby a zipper like structure called a synaptonemal complex

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Crossing over

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genetic rearrangement between nonsister chromotides

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Tetrad

Back 32

the four chromatids in a homologous pair

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Chiasma (chiasmata, plural)

Back 33

The X-shaped regions in tetrads

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Three Major differences from Mitosis and Meiosis

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1. Synapsis and Crossing over
2. Tetrads on the Metaphase plate
3. Speration of Homologues

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Independent assortment

Back 35

when all paternal and maternal homologous are seperated from each other in Meiosis I

Front 36

Recombinant Chromosomes

Back 36

Indidvidual chromosomes that carry genes (DNA) derived from two different parents