Chapter 2 - Reproduction Flashcards
1
Q
Reproduction
(definition)
A
organisms perpetuates itself and its species
2
Q
cell division
(definition)
A
- cell doubles its organelles and cytoplasm
- replicates DNA
- divides into two
3
Q
unicellular organisms
(cell division)
A
means of reproduction
4
Q
mutlicellular organism
(cell division)
A
- method of growth
- development
- replacement of worn-out cells
5
Q
Mitosis
(definition)
A
- division and distribution of DNA to two daughter cells
- each cell receives complete copy of original genome
6
Q
Mitosis
(General steps)
A
- Interphase
- Nuclear division
- Cell division
7
Q
Karyokinesis
A
nuclear division
8
Q
cytokinesis
A
9
Q
Steps of Mitosis
A
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
10
Q
Interphase
A
- 90% of cell’s life
- each chromosome replicated
- after replication - chromosome = two daughter chromatids
- individual chromosomes NOT visible
- DNA uncoiled (chromatin)
11
Q
each chromosome replicated during interphase so that..
A
a complete copy of genome can be distributed to both daughter cells
12
Q
centromere
A
central region where sister chromatids held together
13
Q
chromatin
A
uncoiled DNA
14
Q
Prophase
A
- 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
Q
metaphase
A
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
Q
anaphase
A
centromeres split
each chromatid has own distinct centromere
sister chromatids separate
shortneing of spindle fibers pulls sister chromatids towards opposite poles of cell
17
Q
microtubules
A
makeup spindle fibers
18
Q
telophase
A
- spindle apparatus disappears
- nuclear membrane forms around each set of chromosomes
- each nucleus contains 2N
- chromosomes uncoil
19
Q
Cytokinesis
A
end of telophase
cytoplasm divides into two daughter cells
(animal cells) cleavage furrow forms
20
Q
cleavage furrow
A
- cell membrane indents along equator of cell
- pinches through cell
- separates two nuclei
21
Q
Prophase
(synopsis)
A
chromosomes condense
spindles form
22
Q
Metaphase
(synopses)
A
chromosomes align
23
Q
Anaphase
(synopsis)
A
sister chromatids separate
24
Q
telophase
(synopsis)
A
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
