Chapter 13 ppt (Meiosis and Sexual Life Cycles)

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1

Genes are the units of __________ which make up our segments of _____

hereditary, DNA

2

Sequences of _______ make up genetic information

nucleotides

3

In plants and animals, gametes (egg or sperm) transmit genes from ______ to ______

parent, offspring

4

DNA is subdivided into ________ in _______

chromosomes, nucleus

5

Living organisms are distinguished by their ability to reproduce their______

own kind

6

cats produce

cats

7

maple trees produce

maple trees

8

Heredity is the _____ of traits from one _____ to the next

transmission, generation

9

generation=

inheritance

10

Variation: shows that _____ differ somewhat in appearance from ______ and _____

offspring, parents, siblings

11

Variation: shows that offspring differ somewhat in appearance from parents and siblings even though they inherit ______

similar traits

12

Genetics: the scientific study of ___ and ___

heredity, hereditary variation

13

Chromosome contains a single long _______ w/ ______

DNA molecule coiled, various proteins

14

One chromosome has ___ of genes each of which has a specific sequence of _____

thousands, nucleotides

15

Each gene in an organism’s DNA has a specific ____ on a certain chromosome

locus

16

Locus: area on the ___ where a specific gene is located

chromosome

17

We inherit one set of chromosomes from our ___and one set from our ___

mother, father

18

In humans: __ chromosomes in somatic cells

46

19

In asexual reproduction, one __ produces ______ offspring by _____

parent, genetically identical, mitosis

20

Clone: group of ______ individuals produced by _____ parents

genetically identical, asexually reproducing

21

In sexual reproduction, two __ give rise to offspring that have _____ of genes inherited from the __parents

parents, unique combinations, 2

22

siblings can be __ but not __

similar, identical

23

Siblings vary ______ from each other and parents

genetically

24

____ and ___is alternate in sexual life cycles

fertilization, meiosis

25

A life cycle is the __________ of stages in the ____ of an organism (in this case humans)

generation-to-generation sequence, reproductive history

26

In humans each somatic cell (body cell) has __ chromosomes, made up of __sets

46, 2

27

_____ pairs of chromosomes

23

28

__ set of chromosomes comes from each parent

1

29

A karyotype is a ________ of the ___ in a __

ordered visual representation, chromosomes , cell

30

a karyotype represents _______ or _____

homologous chromosomes, homologs

31

Homologous chromosomes (aka: homologs) Are the_____ composing a ____

2 chromosomes, pair

32

Homologous chromosomes (aka: homologs) have the same ____ (length, centromere position, and staining pattern)

characteristics

33

Homologous chromosomes (aka: homologs) each pair of chromosomes carry ____, _____, the____ inherited characteristics

genes, controlling same

34

Homologous chromosomes (aka: homologs) may have different __ of those___

variations, characteristics

35

First 22 pairs of homologs are called ____

autosomes

36

Sex chromosomes Are ___ from each other in their characteristics

distinct

37

Sex chromosomes Are represented as ___ and ___

X,Y

38

Sex chromosomes determine the ___ of the individual

sex

39

Number of chromosomes in a single set is represented by ___

n

40

A diploid cell has the ___ set of______ chromosomes

complete, all homologous

41

a human has 46 chromosomes express in diploid equation:

(2n = 46)

42

haploid cell is represent as

n

43

a diploid cell is represented as

2n

44

One set of 23 from____ and one set of 23 from _____

mom, dad

45

Somatic cells are

diploid cells

46

In a cell in which DNA synthesis has occurred all the chromosomes are _____ and thus each consists of ________

duplicated, two identical sister chromatids

47

Gametes, sperm and egg cells, are ___ cells containing only ___ set of chromosomes

haploid, 1

48

22 autosomes and 1 sex chromosome =

23 chromosomes

49

Unfertilized eggs only contain an __ chromosome

X

50

a sperm cell can contain an __ or a ___ chromosome

X, Y

51

When fertilization occurs, a ____ cell is formed and the offspring gets one set of chromosomes from the ___ and one from the ____

diploid, father, mother

52

At sexual maturity, the ovaries and testes (gonads) produce ____ gametes by ____ in special cells called ____ cells

haploid, meiosis, germ

53

Meiosis: cell division that ___ the number of sets of chromosomes from ___ to __ in the gametes

reduces. 2, 1

54

During fertilization these gametes, sperm and ovum (egg), ___, forming a _____

fuse, diploid zygote

55

The zygote develops into an ____ by _____

adult organism, mitosis

56

The three main types of sexual life cycles differ in the timing of ___ and ____ according to the spp.

meiosis, fertilization

57

The three main types of sexual life cycles share one thing in common:

genetic variation

58

In animals ____ occurs during gamete formation

meiosis

59

In animals gametes are the only ____ cells

haploid

60

Plants and some algae exhibit an :

alternation of generations

61

Plants and some algae's life cycle includes both ( ) and ( ) ( ) stages

diploid, haploid, multicellular

62

In Plants and some algae the diploid stage is called the ( ) and haploid called spore and gametophyte

sporophyte

63

In Plants and some algae the haploid stage is called the ( ) and ( )

spore,gametophyte

64

In most fungi and some protists meiosis produces ___ cells that give rise to a haploid _____ adult organism

haploid, multicellular

65

In most fungi and some protists the haploid adult carries out _____, producing cells that will become _____

mitosis, gametes

66

Depending on the type of life cycle, either ____ or ____ cells can divide by _____

haploid, diploid, mitosis

67

However, only ____ can undergo _____

diploid, meisosis

68

In all three life cycles the ____ and _____ of chromosomes contribute to ______ in offspring

halving, doubling, genetic variation

69

Meiosis reduces the number of chromosome sets from _____ to ____

diploid, haploid

70

Even though meiosis reduced the number of chromosomes from diploid to haploid they still have ____ before meiosis

interphase

71

Meiosis takes place in how many numbers of sets of cell division

2

72

What are the names of the 2 sets of cell divisions in meiosis

meiosis 1 and meiosis 2

73

Meiosis results in ____ daughter cells with ___ the number of chromosomes than the ____ cell

4, half, parent

74

Meiosis 1 reduces the number of chromosomes from ____ to _____

diploid, haploid

75

Meiosis 1 contains what stages (4)

prophase 1

metaphase 1

anaphase 1

telophase 1

76

Meiosis 2 produces ___, ___ daughter cells

4, haploid

77

Meiosis 2 contains what stages (4)

prophase 2

metaphase2

anaphase 2

telophase 2

78

In early prophase 1 each chromosome pairs with its __

homolog

79

In early prophase 1 what occurs

crossing over

80

What are x-shaped regions called

chiasmata

81

chiasmata are sites of

crossovers

82

In metaphase 1 pairs of homologs line up at the ______ with ___ chromosome facing each pole

metaphase plate, 1

83

Microtubules from one pole are attached to the ____ of one chromosome of each pair and same goes for the other pole.

kinetochore

84

In anaphase 1 pairs of homologous chromosomes _____

separate

85

In anaphase 1, 1 chromosome of each pair moves toward opposite poles guided by the ______

spindle apparatus

86

In anaphase 1 sister chromatids remain ____ at the ______ and move as 1 unit towards the ____

attached, centromere, pole

87

In the beginning of telophase 1 each half of the cell has a ___ set of chromosomes

haploid

88

Each chromosome consists of _____

2 sister chromatids

89

Cytokinesis usually occurs _____ forming _____

simultaneously, 2 haploid daughter cells

90

In animal cells a __________ forms

cleavage furrow

91

In plant cells a ______ forms

cell plate

92

No chromosomal replication occurs between the end of ____ and the beginning of _____ because the chromosomes are already replicated

meiosis 1 , meiosis 2

93

In prophase 2 , a _____ forms

spindle apparatus

94

In late prophase 2, chromosomes move towards the _____

metaphase plate

95

In metaphase 2 the sister chromatids are arranged at the ____

metaphase plate

96

Because of crossing over in meiosis 1 the 2 sister chromatids of each chromosome are no longer _____

genetically identical

97

In metaphase 2 the kinetochore of sister chromatids attach to _____ extending from _____ poles

microtubules, opposite

98

In anaphase 2, the sister chromatids

separate

99

In anaphase 2 the sister chromatids of each chromosome now move as 2 _____ chromosomes toward ______ poles

newly individual, opposite

100

In telophase 2 , the chromosomes arrive at _____ poles

opposite

101

In telophase 2 _____ forms

nuclei

102

In telophase 2 the chromosomes begin _____

decondensing

103

Cytokinesis separates the

cytoplasm

104

at the end of meiosis, there are __ daughter cells, each with a haploid set of ______ chromosomes

4, unreplicated

105

Each daughter cell is _______ from the others and from the parent cell

genetically different

106

replicated homologs pair up and become connected by a zipper-like protein structure known as the

synaptonemal complex

107

replicated homologs pair up and become connected by a zipper-like protein structure (synaptonemal complex) this process is known as

synapsis

108

Meiosis and mitosis can be distinguished from mitosis by __ events in Meiosis 1

3

109

The process of synapsis dissembles expect for one area called the

chiasma

110

The process of synapsis dissembles expect for one area (the chiasmata) where ____ occurs

crossing over

111

crossing over occurs: genetic rearrangement between _____

nonsister chromatids

112

each tetrad contains a

chiasma

113

a tetrad is ____ chromatids of ______ pair

4, homologous

114

at metaphase 1 of meiosis paired homologous chromosomes (tetrads) are positioned on the _____

metaphase plates

115

at metaphase 1 of meiosis paired homologous chromosomes (tetrads) are positioned on the metaphase plates rather than _________ chromosomes

individual replicated

116

at anaphase 1 of meiosis homologous pairs move toward _____ poles of the cell

opposite

117

At anaphase 1 of meiosis cohesins are ___ along chromosome arms to separate _____

cleaved, homologs

118

In anaphase 2 of meiosis the sister chromatids____

separate

119

In anaphase 2 of meiosis cohesins are ___ at the ___ to separate ____

cleaved, centromere, sister chromatids

120

Genetic variation contributes to

evolution

121

Reshuffling of genetic material in meiosis produces

genetic variation

122

Reshuffling of genetic material in meiosis produces genetic variation because it creates different ______ of genes

versions

123

Originally due to mutations: change in the DNA sequence to cause different versions of genes are called

alleles

124

Is eye color a gene or allele

gene

125

Is blue vs. brown eye color a gene or allele?

allele

126

In species that produce sexually the behavior of chromosomes during ____ and ____ are responsible for most of the variation that arises each generation

meiosis , fertilization

127

How many mechanisms are there that contribute to genetic variation

3

128

What are the 3 mechanisms that contribute to genetic variation

Independent assortment of chromosomes

Crossing over

Random fertilization

129

homologous pairs of chromosomes orient randomly at _____ of _____

metaphase 1, meiosis 1

130

Within homologous pairs of chromosomes each pair may orient with either the ___ or ____ homolog independently of other pairs

maternal, paternal

131

In humans, there are more than ____ million possible combinations of chromosomes

8

132

Crossing over produces _____ chromosomes that carry ____ derived from 2 _____

recombinant, genes, different parents

133

In humans, average of ___-____ crossover events occurs per chromosome

1-3

134

The fusion of gametes will produce a ____ with any of about ____ trillion diploid combinations

zygote, 70

135

With the fusion of gametes you don't know which ___ will fertilize which ___

sperm, ovum

136

Mutations are the _____ source of _______

original, genetic variation

137

Sexual reproduction produces new ___ of ____ genes adding more ____

combinations, variant, genetic diversity