Chapter 9: Meiosis

Front 1

Image of chromosomes arranged by pair according to their size, shape and banding patterns

Back 1

Karyotype

Hint 1

Imaging

Front 2

Cell condition where two of each type of chromosomes are present

Back 2

Diploid

Front 3

Cell condition where only one of each type of chromosome is present

Back 3

Haploid

Front 4

What we call any chromosome other than the sex chromosomes

Back 4

Autosome

Front 5

Males have and x and y and females have double x of this

Back 5

Sex chromosomes

Front 6

Member of a pair of chromosomes that are alike and come together in synapsis during prophase of the first mioetic division

Back 6

Homologous chromosome

Front 7

Alternative form of a gene. Occurs at same locus on homologous chromosomes

Back 7

Alleles

Hint 7

Gene

Front 8

Recurring pattern of genetically programmed events in which individuals grow, develop, maintain themselves and reproduce

Back 8

Life cycle

Hint 8

Grow, develop, maintain themselves

Front 9

Production of sperm in males by process of mieosis and maturation

Back 9

Spermatogenesis

Front 10

Production of eggs in females by process of meiosis and maturation

Back 10

Oogenesis

Front 11

Diploid cell formed by the union of two gametes

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Zygote

Hint 11

Sperm and egg merge

Front 12

Pairing of homologous chromosomes during meiosis I

Back 12

Synapsis

Hint 12

During meiosis I

Front 13

The chromatids that are not physically connected but homologous pairs

Back 13

Nonsister chromatids

Hint 13

Non touch chromatids when the homologous pairs line up during synapsis

Front 14

Exchange of information by nonsister chromatids

Back 14

Crossing-over

Front 15

Why do organisms use meiosis rather than mitosis?

Back 15

They use it for reproduction because it reduces the number of chromosomes by half. Creates genetic diversity

Front 16

Summary of mitosis and meiosis in the human life cycle

Back 16

Gametes are produced by meiosis.

Haploid Sperm fertilizes haploid egg to form diploid zygote

Zygote divides by mitosis to grow

Front 17

Explain relationship between sister chromatids and homologous chromosomes

Back 17

Homologous chromosomes are the same chromosomes from each parent

During cell cycle each homologous chromosome duplicates to form two identical sister chromatids

Front 18

Describe two ways in which meiosis produces two genetically different gametes. Why is this important?

Back 18

Crossing over

Shuffling of homologous chromosomes during meiosis I

Basis of evolution

Front 19

What happens during meiosis I prophase I?

Back 19

Nuclear envelope breaks

Nucleolus disappeaes

Spindle appears

Chromosomes condense

Homologous chromosomes undergo synapsis

Crossing over happens between nonsister chromatids

Front 20

What happens during meiosis I metaphase I?

Back 20

Homologous chromosomes align at spindle equator

Each homologous chromosome faces a different spindle pole

Front 21

What happens during meiosis I anaphase I?

Back 21

Homologous chromosomes separate

Reformation of nuclear envelope

Daughter nuclei are haploid, contain only 23 chromosomes

No DNA replication occurs

Front 22

A phase between meiosis I and II where no DNA replication occurs

Back 22

Interkinesis

Front 23

What happens in meiosis II prophase II?

Back 23

Nuclear envelope breaks

Nucleolus disappears

Spindle appears

Chromosomes attach to spindle

Front 24

What happens during meiosis II metaphase II?

Back 24

Chromosomes line up at spindle equator

Sister chromatids face opposite spindle poles

Front 25

What happens in meiosis II anaphase II?

Back 25

Sister chromatids separate

Sister chromatids move toward opposite spindle poles

Both poles receive same number of chromatids

Front 26

What happens during meiosis II telophase II?

Back 26

Spindle disappears

Nuclear envelope forms

Front 27

The failure of homologous chromosomes to separate during metaphase I or sister chromatids during metaphase II during meiosis

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Nondisjunction

Front 28

One type of chromosome being present in 3 copies

Back 28

Trisomy

Front 29

Only one copy of a type of chromosome being present

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Monosomy

Hint 29

22 chromosomes instead of 23

Front 30

Another name for trisomy 21

Back 30

Down syndrome

Front 31

specialized process of cell division that produces four genetically-different daughter nuclei with half the number of chromosomes as the parent cell

Back 31

meiosis

Front 32

forming of a cell after meiosis by splitting apart the cytoplasm

Back 32

cytokinesis

Front 33

Genetic material is replicated only once during meiosis

Back 33

true

Front 34

Chromosome segregation and cytokinesis happens twice during meiosis

Back 34

true

Front 35

meiosis results in one nucleus dividing to produce four daughter nuclei with half the number of chromosomes

Back 35

true

Front 36

These two process generate genetic variability during meiosis

Back 36

crossing over

independent assortment

Front 37

What are the 4 phases of meiosis I?

Back 37

prophase I

metaphase I

anaphase I

telophase I

Front 38

What is the travel path for oocytes?

Back 38

small primary follicles

larger secondary follicles

Graafian follicle - large fluid-filled atrium

mature into egg cell

Front 39

What is the travel path for spermacytes?

Back 39

outer wall of seminiferous tubules

inner lumen of the tubules

mature int sperm call

Front 40

Why are fruit flies used?

Back 40

fast life cycle

small number of chromosomes

distinctive phenotypes

Front 41

Fruit Flies can be anesthetized with this before working with them

Back 41

SmartNap Fly anesthetic