Abac Biol 1107 Campbell Chapter 13 Meiosis

Front 1

___ is the scientific study of heredity and variation

Back 1

Genetics

Front 2

____ is the transmission of traits from one generation to the next

Back 2

Heredity

Front 3

_____ is the inherited differences among individuals of the same species

Back 3

Variation

Front 4

____ are the units of heredity, and are made up of segments of DNA

Back 4

Genes

Front 5

Genes are passed to the next generation via reproductive cells called _______

Back 5

gametes

Front 6

____ are cells that function in sexual reproduction; an egg or a sperm whose union, in sexual reproduction

Back 6

Gametes

Front 7

Each gene has a specific location called a ____ on a certain chromosome

Back 7

locus

Front 8

A ______is a group of genetically identical individuals from the same parent

Back 8

clone

Front 9

In __________ (sexual/asexual) reproduction, two parents give rise to offspring that have unique combinations of genes inherited from the two parents

Back 9

sexual

Front 10

______ is the generation-to-generation sequence of stages in the reproductive history of an organism

Back 10

Life cycle

Front 11

Human somatic cells have ____ pairs of chromosomes

Back 11

23

Front 12

____is any cell other than a gamete

Back 12

Somatic cell

Front 13

A _______ is an ordered display of the pairs of chromosomes from a cell

Back 13

karyotype

Front 14

The two chromosomes in each pair are called ______

Back 14

homologous chromosomes, or homologs

Front 15

Chromosomes in _______ are the same length and shape and carry genes controlling the same inherited characters

Back 15

homologous pair

Front 16

Pairs of chromosomes where the members of the pairs are dissimilar and are involved in sex determination.

Back 16

Sex chromosomes

Front 17

The sex chromosomes of human females have ______

Back 17

XX

Front 18

The sex chromosomes of human males have ______

Back 18

one X and one Y chromosome

Front 19

In humans, 22 pairs of chromosomes are called _____

Back 19

autosomes

Front 20

A ___________ has two sets of chromosomes

Back 20

diploid cell (2n)

Front 21

Each replicated chromosome consists of two identical ______

Back 21

sister chromatids

Front 22

One of two halves of a replicated chromosome attached by a centromere

Back 22

Chromatid

Front 23

A gamete (sperm or egg) contains a single set of chromosomes, and is ______

Back 23

haploid (n)

Front 24

In an unfertilized egg (ovum), the sex chromosome is ______

Back 24

X

Front 25

In a sperm cell, the sex chromosome may be ____

Back 25

either X or Y

Front 26

_____is the union of gametes (the sperm and the egg)

Back 26

Fertilization

Front 27

The fertilized egg is called a ______ and has one set of chromosomes from each parent

Back 27

zygote

Front 28

a cell that results from the union of two gametes

Back 28

Zygote

Front 29

The zygote produces somatic cells by _____and develops into an adult

Back 29

mitosis

Front 30

_____are the only types of human cells produced by meiosis, rather than mitosis

Back 30

Gametes

Front 31

______ reestablishes the diploid state in humans.

Back 31

Fertilization

Front 32

______ are the only haploid cells in animals

Back 32

Gametes

Front 33

_______(Gametes/Somatic) cells fuse to form a _____ (haploid/diploid) zygote that divides by ______ (mitosis/meiosis) to develop into a multicellular organism

Back 33

Gametes
diploid
mitosis

Front 34

Meiosis takes place in two sets of cell divisions, called ____ and _____

Back 34

meiosis I
meiosis II

Front 35

The two cell divisions result in ____ daughter cells, rather than the _____ daughter cells in mitosis

Back 35

four
two

Front 36

Each daughter cell at the end of meiosis has only ______ as many chromosomes as the parent cell

Back 36

half

Front 37

In _________ (meiosis I/meiosis II) homologs pair up and separate, resulting in two haploid daughter cells with replicated chromosomes

Back 37

Meiosis I

Front 38

In _________ (meiosis I/meiosis II) sister chromatids separate

Back 38

meiosis II

Front 39

The sister chromatids are genetically identical and joined at the ____

Back 39

centromere

Front 40

______ is when homologous chromosomes loosely pair up, aligned gene by gene

Back 40

Synapsis

Front 41

the exchange of corresponding chromatid segments between homologous chromosomes.

Back 41

Crossing over

Front 42

During synapsos, each pair of chromosomes forms a _____, a group of four chromatids

Back 42

tetrad

Front 43

X-shaped regions where crossing over occurred

Back 43

Chiasmata

Front 44

Stage of cell division when homologous chromosomes line-up at the equator

Back 44

Metaphase I of meiosis only

Front 45

Microtubules from one pole are attached to the kinetochore of one chromosome of each homologous pair

Back 45

Metaphase I of meiosis only

Front 46

Stage of cell division when microtubules from the other pole are attached to the kinetochore of the other chromosome

Back 46

Metaphase I of meiosis only

Front 47

Stage of cell division when pairs of homologous chromosomes separate

Back 47

Anaphase I of meiosis only

Front 48

Stage of cell division when sister chromatids remain attached at the centromere and move as one unit toward the pole

Back 48

Anaphase I of meiosis only

Front 49

In the beginning of _____ , each half of the cell has a haploid set of chromosomes; each chromosome still consists of two sister chromatids

Back 49

telophase I

Front 50

During meiosis II, because of _____, the two sister chromatids of each chromosome are no longer genetically identical.

Back 50

crossing over in meiosis I

Front 51

At the end of meiosis, there are ____ daughter cells, each with a ____set of unreplicated chromosomes

Back 51

four
haploid

Front 52

Meiosis reduces the number of chromosomes sets from _____ to ______, producing cells that differ genetically from each other and from the parent cell

Back 52

diploid
haploid

Front 53

Synapsis and crossing over in _____

Back 53

prophase I

Front 54

At the equator in_____, there are paired homologous chromosomes (tetrads)

Back 54

metaphase I

Front 55

At_______, it is homologous chromosomes, instead of sister chromatids, that separate

Back 55

anaphase I

Front 56

Sister chromatid ______ allows sister chromatids of a single chromosome to stay together through meiosis I

Back 56

cohesion

Front 57

Protein complexes called _____are responsible for this cohesion.

Back 57

cohesins

Front 58

______ are the original source of genetic diversity

Back 58

Mutations

Front 59

Reshuffling of alleles during sexual reproduction produces __________

Back 59

genetic variation

Front 60

What are three mechanisms contribute to genetic variation?

Back 60

Independent assortment
Crossing over
Random fertilization

Front 61

Homologous pairs of chromosomes orient randomly at metaphase I of meiosis this is called _______

Back 61

Independent assortment

Front 62

_______ contributes to genetic variation by combining DNA from two parents into a single chromosome

Back 62

Crossing over

Front 63

______ adds to genetic variation because any sperm can fuse with any ovum (unfertilized egg)

Back 63

Random fertilization

Front 64

The fusion of two gametes produces a ________

Back 64

zygote

Front 65

Stage of cell division when crossing-over occurs

Back 65

Prophase I of meiosis only

Front 66

Any chromosome other than the sex chromosomes.

Back 66

Autosomes

Front 67

Maternal and paternal copies of the same chromosome

Back 67

Homologous chromosomes

Front 68

Body cells are called _____

Back 68

Somatic cells