Chapter 2 - Reproduction Flashcards Preview

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Flashcards in Chapter 2 - Reproduction Deck (159):
1

Reproduction

(definition)

organisms perpetuates itself and its species

2

cell division

(definition)

  • cell doubles its organelles and cytoplasm
  • replicates DNA
  • divides into two

3

unicellular organisms 

(cell division)

means of reproduction

4

mutlicellular organism

(cell division)

  • method of growth
  • development
  • replacement of worn-out cells

5

Mitosis

(definition)

  • division and distribution of DNA to two daughter cells
  • each cell receives complete copy of original genome

6

Mitosis

(General steps)

  1. Interphase
  2. Nuclear division
  3. Cell division

7

Karyokinesis

nuclear division

8

cytokinesis

9

Steps of Mitosis

  1. Interphase
  2. Prophase
  3. Metaphase
  4. Anaphase
  5. Telophase
  6. Cytokinesis

10

Interphase

  • 90% of cell's life
  • each chromosome replicated 
  • after replication - chromosome = two daughter chromatids
  • individual chromosomes NOT visible
  • DNA uncoiled (chromatin)

11

each chromosome replicated during interphase so that..

a complete copy of genome can be distributed to both daughter cells

12

centromere

central region where sister chromatids held together

13

chromatin

uncoiled DNA

14

Prophase

  • Chromosomes condense
  • (animals) centriole pairs separate and move towards opposite poles of cell
  • spindle apparatus forms between 
  • nuclear membrane dissolves
  • spindle fibers interact with chromosomes

15

metaphase

centriole pairs at opposite poles of cell

fibers of spindle apparatus attach to each chromatid at centomere to align chromosomes at center of cell (equator)

forms metaphase plate

16

anaphase

centromeres split 

each chromatid has own distinct centromere

sister chromatids separate

shortneing of spindle fibers pulls sister chromatids towards opposite poles of cell 

 

17

microtubules

makeup spindle fibers

18

telophase

  • spindle apparatus disappears
  • nuclear membrane forms around each set of chromosomes
  • each nucleus contains 2N
  • chromosomes uncoil 

 

19

Cytokinesis

end of telophase

cytoplasm divides into two daughter cells

(animal cells) cleavage furrow forms

20

cleavage furrow

  • cell membrane indents along equator of cell
  • pinches through cell
  • separates two nuclei

21

Prophase 

(synopsis)

chromosomes condense

spindles form

22

Metaphase

(synopses)

chromosomes align

23

Anaphase

(synopsis)

sister chromatids separate

24

telophase

(synopsis)

new nuclear membrane forms

25

chromatid composed of..

double-stranded molecule of DNA

26

sister chromatids

identical copies of each other

27

chromosome

single chromatid

or

pair of chromatids attached at centromere

28

Mitosis in Plant Cells

(2 major differences bw plant and animal)

plants lack centrioles

spindle apparatus synthesized by microtubule organizing centers (invisible)

29

Why no cleavage furrow in plant cells?

(cytokinesis)

plant cells are rigid

30

how do plant cells divide?

(cytokinesis)

formation of a cell plate

31

cell plate 

(cytokinesis in plant cells)

expanding partition 

grows outward from interior of cell until reaches cell membrane

way in which plant cells divide (cytokinesis)

32

Meiosis

process by which sex cells are formed

33

sexual reproduction 

(meiosis)

fusion of two gametes

34

gametes

(meiosis)

specialized sex cells produced by each parent

35

similarities bw meiosis and mitosis

cell duplicates its chromosomes before undergoing process

36

differences between mitosis and meiosis

mitosis preserves diploid (2N)

meiosis produces haploid (1N)

meiosis halves number of chromosomes

 

37

meiosis involves ___ divisions of primary sex cells

2

38

Mieosis results in ___ haploid cells

4

39

Phases of Meiosis

  1. Interphase
  2. Prophase 1
  3. Metaphase 1
  4. Anaphase 1
  5. Telophase 1
  6. metaphase 2
  7. anaphase 2
  8. telophase 2

40

Interphase 

(meiosis)

parent cell's chromosomes replicated

result in 2N number of sister chromatids

41

First Meiotic Division produces

(Meiosis)

two intermediate daughter cells with N chromosomes with sister chromatids

42

Prophase 1 

(meiosis)

  • chromatin ---> chromosomes
  • spindle apparatus appears
  • necleoli, nuclear membrane disappear
  • homologous chromosomes intertwine
  • recombination, crossing over occurs

 

43

Homologous chromosomes 

(prophase 1 - meiosis)

chromosomes that code for same traits

one inhereted from each parent

44

synapsis

homologous chromosomes come together and intertwine

45

tetrad

(prophase 1 - meiosis)

synaptic pair of homologous chromosomes containing 4 chromatids

46

crossing over

(prophase 1 - meiosis)

chromatids of homologous chromsomes break at corresponding points and exchange DNA

47

crossing over occurs between...

homologous chromosomes

NOT sister chromatids of same chromosomes

48

recombination results in...

genetic diversity within a species

sister chromatids no longer identical after recombination

49

anaphase 1

(meiosis)

homologous pairs pulled to opposite poles

(disjunction)

50

Disjunction

(Anaphase 1 - Meiosis)

each chromosome (paternal) separates from homologue (maternal)

either chromosome ends up in either daughter cell

51

each daughter cell has...

(as a result of meiosis 1)

unique pool of genes from random mixture of maternal and paternal origin

52

telophase 1

(meiosis)

nuclear membrane forms around each new nucleus

each chromosome consists of sister chromatids joined at centromere

53

2nd Meiotic Division

(meiosis)

similiar to mitosis

not preceded by chromosomal replication

1. metaphase ii

2. anaphase ii

3. telophase ii

54

metaphase 2

(meiosis)

chromosomes align at equator

55

anaphase 2 

(meiosis)

chromosomes separate and move to opposite poles

56

telophase 2

(meiosis)

chromosomes are surrounded by reformed nuclear membrane

57

final product of meiosis

4 haploid (1N) games

 

 

58

human females 

product of meiosis

4 haploid gametes

only one daughter cell becomes functional gamete

59

Mitosis Summary

2N --> 2N

in all dividing cells

homologous chromosomes don't pair up

no crossing over

60

Meiosis Summary

2N ----> N

only in sex cells

homologous chromosomes pair up at metaphase plate 

form tetrads

crossing over occurs

61

Sexual Reproductive Mechanisms

Sexual Reproduction in Animals

Sexual Reproduction in Humans

 

62

sexual reproduction differs from asexual in that there are...

two parents

63

end result of sexual reproduction

genetically unique offspring

64

sexual reproduction occurs via

fusion of two gametes

65

gametes

specialized sex cells produced by each parent (result of meiosis)

66

Sexual Reproduction Requires

  • production of functional sex cells or gametes by adult organisms
  • union of these cells to form zygote (fertilization or conjugation)
  • development of zygote into another adult

 

67

Sexual Reproduction in Animals

formation and fertilization of gametes 

regulation of processes by both parents

68

Gonads

(sexual reproduction in animals)

male and female

organs

produces gametes

male - testes

female - ovaries

69

testes

male gonads

produce sperm in tightly coiled seminiferous tubules

70

ovaries

female gonads

produce oocytes (eggs)

 

71

oocytes

eggs produced by ovaries (female gonads)

72

Hermaphrodites

species with both female and male gonads

e.g. hydra, earthworm

73

spermatogenisis

(sexual reproduction in animals)

sperm production

occurs in seminiferous tubules

74

spermatogonia

diploid cells

undergo meiosis 

produce 4 haploid sperm (equal in size)

75

mature sperm

(form)

elongated cell 

head, tail, neck, body

76

head of sperm

consists of nucleus

contains paternal genome

77

flagellum

tail of sperm

propels sperm

78

neck and body of sperm

contain mitochondria

provide energy for locomotion

79

Oogenesis

(sexual reproduction in animals)

production of female gametes

occurs in ovaries

80

process of oogenesis

one diploid primary female sex cell ---> meiosis in ovaries ---> single mature egg

81

each meiotic division of oogenesis produces

polar body

82

polar body

small cell 

contains nucleus

rapidly degenerate

83

mature ovum is/contains

(oogenesis)

large cell

  • cytopolasm
  • RNA
  • organelles
  • nutrients needed by developing embryo

84

Fertilization

definition

types

(sexual reproduction in animals)

union of egg and sperm nuclei

forms zygote (diploid)

  • external fertilization
  • internal fertilization

 

85

External Fertilization

who and process

(Fertilization)

(sexual reproduction in animals)

vertebrates that reproduce in water

(fish and amphibians)

female lays eggs in water

male deposits sperm in vicinity

many eggs must be layed

 

86

con of external fertilization

indirect

reduces changes of fertilization

female must lay many eggs

87

sperm characteristics

(external fertilization)

flagella - to swim through water to eggs

88

Internal Fertilization

who 

terrestrial vertebrates

 

89

internal fertilization

pros

direct route

increase chance of success

female produces fewer eggs

90

factors affecting number of eggs produced by female

(3 factors)

  1. internal vs. external fertilization
  2. early development outside/inside mother's body
  3. amount of prenatal care after birth

91

Human Reproduction 

(4 components)

  1. Male Reproductive Physiology
  2. Female Reproductive Physiology
  3. Female Sex Hormones
  4. The Menstrual Cycle

92

Male Reproductive Physiology

Sperm pass from:

(SEVEn UP)

seminiferous tubules --> testes --> vas deferens --> ejaculatory duct --> urethra --> penis

93

 http://www.maleinfertilitycure.com/image/intro_to_male_infertility.jpg

male reproductive anatomy

94

testes located in 

scrotum - external pouch

95

scrotum

maintains testes temp 2-4C lower than body temp

(essential for sperm survival)

96

urethra

passes through penis

opens to outside at tip

serves for reproductive and excretory systems

97

testes re hormones

production of testosterone

98

testosterone

regulates male sex characteristics

(facial and pubic hair, voice changes, etc)

99

Female Reproductive Anatomy

ovaries --> releases immature ovum --> abdominal cavity ---> oviduct ---> fallopian tube --> uterus --> cervix --> vaginal canal --> open world

100

ovaries (location)

in abdominal cavity

below digestive system

101

ovaries consist of: 

thousands of follicles

102

once a month, the ovary

releases an immature ovum into the abdominal cavity

103

follicle

(form and function)

multilayered sac of cells

contains, nourishes, protects immature ovum

104

follicle cells produce

estrogen

105

uterus

muscular chamber

site of fetal development

106

cervix

lower, narrow end of uterus

connects with vaginal canal

107

vaginal canal

site of sperm deposition during intercourse

passageway through which baby expelled

108

at birth

(re: eggs)

all eggs that female will ovulate are present

(no production throughout lifetime)

109

Female Sex Hormones

synthesized and secreted by

ovaries

110

female sex hormones are

estrogens 

progesterone

111

secretion of estrogen and prostegerone regulated by:

LH 

FSH

112

LH

FSH 

regulated by

GnRH

113

Estrogens 

(Female Sex Hormones)

are and cause (5)

  • steroid hormones
  • cause:
  1. female menstruation
  2. dev reproductive tract
  3. dev secondary sexual characteristics
  4. sex drive
  5. thickening of endometrium (uterine wall)

114

estrogens are secreted by

  1. ovarian follicles 
  2. corpus luteum

115

progesterone

(female sex hormones)

are and cause (1)

steroid hormone

dev maintenance of endometrial walls ---> prep for implantation

116

progesterone secreted by

corpus luteum 

117

progesterone secreted during

luteal phase 

(menstraul cycle)

118

Menstrual Cycle

hormones secreted by

  1. ovaries
  2. hypothalamus
  3. anterior pituitary

119

menstrual cycle duration

puberty --> menopause

monthly cyclical 

120

Menstrual Cycle Phases

  1. Follicular
  2. Ovulation
  3. Luteal
  4. Menstruation

121

Follicular Phase

(menstrual cycle)

1. cessation of menstrual flow

2. FSH promotes dev of follicle

3. follicle grows, secretes estrogen

122

FSH released by

(follicular phase)

Follicle Stimulating Hormone

anterior pituitary

123

Ovulation

(menstrual cycle)

  1. peak in estrogen levels ---> surge in LH
  2. triggered by LH surge at midcycle
  3. mature ovarian follicle bursts 
  4. releases ovum

124

Luteal Phase

(menstrual cycle)

  1. LH induces ruptured follicle ---> corpus luteum
  2. CL secretes estrogen, progesterone
  3. Progesterone --> glands of endometrium to mature
  4. glands of endometrium --> secretions to prep for implantation of embryo
  5. LH, FSH inhibited

125

LH

Luteinizing Hormone

126

corpus luteum secretes

estrogen, progesterone

during luteal phase

127

progesterone and estrogen essential during luteal phase for

maintenance of endometrium

128

Menstruation

if ovum not fertilized

(menstrual cycle)

 
  1. corpus luteum atrophies
  2. drop in progesterone and estrogen
  3. endometrium + superficial blood vessels slough off
  4. menses
  5. LH + FSH begin to rise again

129

menses

menstrual flow

130

Menstruation 

(menstrual cycle)

if fertilization occurs

  1. developing placenta produces hCG
  2. hCG maintains corpus luteum
  3. estrogen, progesterone maintained
  4. uterus maintained
  5. until placenta takes over production of e + p

131

hCG

human chorionic gonadotrophin

132

Asexual Reproduction

reproduction w/o fertilization

 

133

new organisms formed by

(asexual reproduction)

division of single parent cell

carbon copies of parent cells

134

offspring are not identical to parent cells in asexual reproduction when

random mutations

135

Types of asexual reproduction

  • fission
  • budding
  • regeneration
  • parthenogenesis

136

Prokaryotes reproduce

asexually

137

in animals, asexual rep more common in 

invertebrates

138

all plants use

(reproduction)

asexual reproduction

139

Binary Fission

process

(asexual reproduction)

 
  • DNA replicates
  • plasma membrane and cell wall grow inward along midline of cell
  • divide into 2 = parts
  • contain cytoplasm + duplicate of parent cell

 

140

binary fission occurs in 

prokaryotes

some primitive eukaryotes

one-celled oganisms

e.g. amoebae, paramecia, algae, bacteria

141

Budding 

produces

(asexual reproduction)

replication of nucleus 

unequal cytokinesis

 

142

Budding process

1. cell membrane pinches inward

2. new cell forms

3. new cell smaller, genetically identical to parent cell

4. new cell grows to adult size

 

143

Budding 

(two options for growth of new cell)

1. separate immediately 

2. remain attached, develop as outgrowth, separate later

144

Budding occurs in 

hydra

yeast

145

Regeneration

(definition)

(asexual reproduction)

regrowth or lost/injured body part

146

regeneration

process

mitosis

147

extent of regeneration

some lower animals --> extensive capabilities

e.g. starfish - 

may regenerate body from arm

arm must include central disk 

e.g. salamanders/tadpokes

regenerate new limbs - extend depends on nerve damage to severed body part

148

central disk 

(starfish)

body control center

center of body, from which radiate arms

149

Parthenogenesis

definition

(asexual reproduction)

dev. of unfertilized egg into adult organism

150

parthenogenesis occurs naturaly in

some lower organisms

151

e.g. of parthenogenesis 

most species of bees and ants

male bees via parthenogenesis

worker and queen bees via fertilized eggs

152

artificial parthenogenesis

eggs of rabit + frogs 

stimulated by electric shock or pin-prick

153

Sexual Reproduction in Plants

alternation of generations

2N sporophyte gen

N gametophyte gen

154

length of gen in plant sexual rep

relative lengths of two stages vary with plant type

evo trend --> increased dominance of sporophyte gen

155

Cycle of plant sexual rep

Sporophyte 2N --> Spore 1N --> Gametophyte 1N --> fertilization 1N + 1N gametes --> Sporophyte 2N

156

Gametophyte Generation

(Plant sexual rep)

haploid gametophyte gen produces gametes via mitosis

157

fertilization 

(gametophyte generation - plant sexual rep)

male and female gametes at fertilization restores diploid sporophyte generation

158

gametophyte gen vs. sporophyte gen

gametophytes rep sexually

sporophytes rep asexually

159