Reproduction Flashcards
(200 cards)
1
Q
Purpose of reproduction
A
“To produce new organisms similar to themselves
2
Q
Two types of reproduction
A
“Asexual and sexual.”
3
Q
Key events in sexual reproduction
A
“Meiosis and fertilization.”
4
Q
Meiosis’s role
A
“Halves the number of chromosome sets (2n to n) to produce haploid cells/gametes.”
5
Q
Fertilization’s role
A
“Combines chromosomes from two haploid gametes to form a diploid (2n) zygote.”
6
Q
Needs of sexual reproduction
A
“Gonads
7
Q
Prevalence of sexual reproduction
A
“Common in most organisms
8
Q
Sexual reproduction in hermaphrodites
A
“Involves gametes from separate individuals.”
9
Q
Genetic variation in sexual reproduction
A
“Introduced during meiosis and fertilization.”
10
Q
Crossing over
A
“Occurs between chromatids of homologous chromosomes during meiosis.”
11
Q
Independent assortment
A
“Homologous chromosomes separate independently during the first nuclear division of meiosis.”
12
Q
Result of meiosis
A
“Gametes with different genetic makeup.”
13
Q
Result of fertilization
A
“Genetically unique zygote formed from fusion of gametes from two individuals.”
14
Q
Importance of genetic variation
A
“Adaptation to environment
15
Q
Overall importance of sexual reproduction
A
“Contributes to species survival and continuation of life.”
16
Q
Vertebrate sexual reproduction
A
“Involves haploid gamete formation (meiosis)
17
Q
Vertebrate sex separation
A
“Individuals are male or female
18
Q
Vertebrate reproductive strategies
A
“Range from external fertilization to viviparity
19
Q
Fertilization in fishes and amphibians
A
“External
20
Q
Parental care in fishes and amphibians
A
“Most do not look after their young.”
21
Q
Fish eggs
A
“Numerous
22
Q
Amphibian eggs
A
“Many
23
Q
Amphibian larvae
A
“Actively feed and develop before becoming adults.”
24
Q
Wastage in fish and amphibian reproduction
A
“High
25
Reptile, bird, and mammal fertilization
"Internal
26
Adaptations for internal fertilization
"Specialized organs to bring sperm and egg together inside the female."
27
Advantages of internal fertilization
"Safer environment for gametes
28
Amniote egg
"Laid by reptiles and birds
29
Reptile egg laying
"Eggs laid in crevices or buried in sand
30
Bird egg laying
"Eggs laid in nests
31
Mammalian embryo development
"Embryo retained and nourished within the female's uterus via the placenta."
32
Mammalian egg
"Small amount of yolk
33
Amnion function in mammals
"Fluid-filled sac protecting the embryo."
34
Placenta formation
"Embryo's part from allantois and chorion
35
Mammalian parental care
"Young born live
36
Efficiency of reproduction in birds and mammals
"High
37
Flowering plant reproduction
"Most are bisexual
38
Products of meiosis in flowering plants
"Haploid spores (not gametes) that produce haploid gametophytes (pollen grain and embryo sac) through mitosis."
39
Gametophyte
"Haploid structure (pollen grain/embryo sac) that produces gametes."
40
Process after gamete fusion in flowering plants
"Diploid zygote formed
41
Seed function
"Contains food store for embryo
42
Seed germination
"Seed germinates and grows into a new plant (sporophyte)."
43
Plant sexual life cycle
"Alternation of haploid gametophyte and diploid sporophyte generations."
44
Plant gametophytes
"Reduced
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Plant Pollination
"External agents carry male gametes (in pollen) to where the eggs are."
46
Plant Male Gametes
"Non-motile
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Adaptation in Flowering plants
"Flowering plants do not need water to transport their male gametes"
48
Fertilization Uniqueness in Flowering Plants
"A pollen grain produces two male gametes"
49
Double Fertilization
"One male gamete fertilizes the egg (forms zygote)
50
Seed Development
"Zygote grows into a seed without needing water."
51
Seed Germination Requirement
"Needs to absorb water to germinate and develop into a young plant"
52
Vertebrate reproductive system
"Consists of gonads
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Gonads Function
"Produce gametes and hormones for reproduction."
54
Types of Gonads
"Testes (male
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Reproductive ducts and glands function
"Store/transfer gametes
56
Urinogenital system
"Excretory and reproductive systems represented together (ducts drain into urine-carrying ducts)."
57
Cloaca
"Cavity where alimentary
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Sperm-transfer organ
"Males of mammals
59
External genitals
"Parts of the reproductive system seen externally."
60
Importance of external genitals
"Help identify male and female mammals."
61
Human male external genitals
"Scrotal sacs and penis."
62
Testes location
"Lower abdomen in young males
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Scrotum function
"Sac outside the body that keeps testes at a temperature slightly below body temperature for sperm production"
64
Testis structure
"Hundreds of compartments with seminiferous tubules."
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Seminiferous tubules function
"Produce sperms."
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Epididymis
"6m long coiled tubule outside each testis
67
Sperm duct/vas deferens
"Muscular tube that carries sperm from the epididymis."
68
Urethra (male)
"Muscular tube through the penis
69
Accessory glands
"Seminal vesicles
70
Seminal fluid
"Secretions from accessory glands
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Semen
"Milky fluid
72
Penis function
"Conveys urine and semen
73
Penis structure
"Cylindrical organ with erectile tissue
74
Erection
"Blood pumped into erectile tissue
75
Glans penis
"Sensitive region at the tip of the penis
76
Foreskin/prepuce
"Retractible skin covering the glans penis."
77
Circumcision
"Surgical removal of foreskin."
78
Sperm production timing (human)
"Begins at puberty
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Sperm production rate (human)
"About 300 million daily."
80
Sperm production site
"Seminiferous tubules."
81
Spermatogenesis
"Cells in seminiferous tubules undergo meiosis to form spermatids
82
Sperm storage
"Epididymis."
83
Sperm viability
"Mature sperms can remain viable in sperm ducts for up to three months."
84
Sperm structure
"Head (nucleus
85
Acrosome
"Sac at the sperm head tip
86
Sperm motility
"Tail movements
87
Hormonal control of male sexual activity
"Pituitary gonadotropins regulate testes function."
88
Testosterone
"Male sex hormone
89
Human female urinary/reproductive passages
"Separate and open separately to the exterior."
90
Vulva
"Female external genitals."
91
Vulva components
"Folds of skin surrounding openings
92
Clitoris
"Erectile
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Ovaries
"Female gonads
94
Oviduct/Fallopian tube
"Tube with a funnel-shaped opening near each ovary."
95
Fimbriae
"Muscular finger-like structures with cilia that waft ova into the oviduct."
96
Oviducts
"Narrow spiraling tubes with muscular walls lined with mucus-secreting cells
97
Uterus/womb
"Muscular organ with endometrium lining."
98
Endometrium
"Mucous membrane lining the uterus."
99
Cervix
"Ring of muscles connecting the uterus to the vagina."
100
Vagina
"Muscular tube leading from the cervix to the outside."
101
Hymen
"Fold of connective tissue at the entrance of the vagina (may be present)."
102
Number of offspring (human)
"Usually one at a time."
103
Uteri (other mammals)
"Some mammals have two uteri that unite to lead into the vagina."
104
Vestibule
"Common urinogenital passage in some mammals (e.g. rabbit)."
105
Primary oocytes
"Potential egg cells in ovaries at birth (about 200
106
Mature ova development
"400-500 develop during a female's reproductive life (puberty to menopause)."
107
Menstrual cycle events
"Ovum maturation
108
Menstrual cycle length
"28 days."
109
Menstrual cycle control
"Hormones ensure uterus is ready for fertilized ovum."
110
Follicle development
"Primary oocyte surrounded by granular cells
111
Graafian follicle
"Mature follicle with fluid and secondary oocyte
112
Ovulation
"Release of ovum from ovary
113
Ovum coverings
"Zona pellucida (protein coat) and layer of granular cells."
114
Ovum transport
"Waited into oviduct
115
Corpus luteum
"Ruptured Graafian follicle develops into corpus luteum
116
Corpus luteum fate
"If no fertilization
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Menstrual flow
"Sloughing of extra uterine endometrial tissue and some blood
118
Endometrium rebuilding
"Oestrogen causes cells of the endometrium to divide rapidly
119
Endometrium maintenance
"Secretion of mucus maintains the endometrium in an optimal state for the implanting of an embryo."
120
Sexual cycle in most other mammals
"The sexual cycle does not occur monthly but rather at specific times of the year."
121
Oestrous cycle
"Most mammals have an oestrous cycle rather than a menstrual cycle."
122
Differences between the oestrous and menstrual cycle
"The main difference is that in the oestrous cycle
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Oestrous and behavioural changes
"In most mammals
124
Hormonal control of female sexual activity
"The female sexual cycle is controlled by several hormones."
125
Pituitary gonadotropins in females
"At puberty
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FSH function in females
"FSH stimulates the development of the Graafian follicle."
127
Oestrogen function
"Oestrogen
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Oestrogen functions
"Stimulates the repair and thickening of the endometrium
129
LH function
"LH brings about ovulation and the development of the corpus luteum."
130
Progesterone function
"Progesterone
131
Hormone levels if fertilization occurs
"If fertilization and implantation occur
132
Placental hormone
"The placenta also secretes a hormone (progesterone) that takes over the function of the corpus luteum."
133
Hormone levels if fertilization does not occur
"If fertilization does not occur
134
Result of falling hormone levels
"This results in the breakdown of the endometrium and the start of a new cycle."
135
Pregnancy
"Pregnancy or gestation is the period from fertilization to birth."
136
Fertilization site
"In humans
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Fertilization process
"Only one sperm penetrates the egg cell membrane and fertilizes the egg."
138
Egg changes after fertilization
"After fertilization
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Zygote formation
"The nuclei of the sperm and egg then fuse to form a zygote."
140
Cleavage
"The zygote undergoes a series of mitotic divisions as it passes down the oviduct to form a solid ball of cells
141
Blastocyst formation
"The morula develops into a hollow ball of cells
142
Implantation
"The blastocyst becomes embedded in the endometrium about seven days after fertilization."
143
Placenta development
"The placenta develops from both embryonic and maternal tissues."
144
Placenta functions
"It is the organ of gaseous exchange
145
Placental hormones
"The placenta also secretes progesterone and oestrogen which maintain the endometrium and prevent the occurrence of a new cycle."
146
Gestation period
"The length of time the embryo develops in the uterus varies from species to species."
147
Human gestation period
"In humans
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Embryonic development
"During the first three months (first trimester)
149
Organogenesis
"All the main organs are formed during this period."
150
Fetal development
"After three months
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Birth (parturition)
"At the end of the gestation period
152
Birth process
"The uterus undergoes strong muscular contractions (labour) to expel the baby through the vagina."
153
Amnion's role in birth
"The amnion bursts and its fluid (amniotic fluid) lubricates the birth canal."
154
Placenta and umbilical cord after birth
"The placenta and umbilical cord are expelled as the afterbirth."
155
Lactation
"After birth
156
Milk composition
"Milk is a rich fluid containing all the necessary nutrients for the growth of the young."
157
Hormonal control of lactation
"Milk production is under hormonal control."
158
Placental hormones and milk production
"The high levels of progesterone and oestrogen produced by the placenta during pregnancy inhibit milk production."
159
Prolactin and milk production
"After birth
160
Oxytocin and milk release
"Suckling by the baby stimulates the release of oxytocin from the pituitary gland
161
Contraception
"Contraception is the prevention of pregnancy."
162
Natural methods of contraception
"These methods involve no special devices and are based on the woman's menstrual cycle."
163
Rhythm method
"The rhythm method involves avoiding sexual intercourse during the fertile period
164
Fertile period
"The fertile period is about two days before and two days after ovulation."
165
Temperature method
"The temperature method involves taking the woman's temperature daily."
166
Temperature and ovulation
"There is a slight rise in temperature (about 0.5°C) at ovulation."
167
Withdrawal method
"The withdrawal method involves the man withdrawing his penis from the vagina before ejaculation."
168
Effectiveness of natural methods
"These natural methods are not very reliable."
169
Barrier methods of contraception
"These methods prevent the sperm from reaching the egg."
170
Condom
"The condom is a rubber sheath that is placed over the penis before intercourse."
171
Diaphragm
"The diaphragm is a rubber cap that is placed over the cervix."
172
Spermicides
"Spermicides are chemicals that kill sperm."
173
Effectiveness of barrier methods
"Barrier methods are more reliable than natural methods
174
Intrauterine device (IUD)
"The IUD is a small plastic or metal device that is inserted into the uterus by a doctor."
175
IUD action
"The IUD prevents implantation of the fertilized egg."
176
Hormonal methods of contraception
"These methods use hormones to prevent ovulation or implantation."
177
Oral contraceptives (the pill)
"Oral contraceptives contain synthetic progesterone and oestrogen."
178
Pill action
"The pill prevents ovulation by inhibiting the release of FSH and LH."
179
Mini-pill
"The mini-pill contains only progesterone."
180
Injectable contraceptives
"Injectable contraceptives contain progesterone and are given every three months."
181
Implantable contraceptives
"Implantable contraceptives are small rods that are inserted under the skin and release progesterone."
182
Morning-after pill
"The morning-after pill contains a high dose of progesterone and can prevent pregnancy if taken within 72 hours of unprotected intercourse."
183
Surgical methods of contraception
"These methods are permanent and involve surgery."
184
Vasectomy
"Vasectomy involves cutting and tying the sperm ducts."
185
Tubal ligation
"Tubal ligation involves cutting and tying the fallopian tubes."
186
Infertility
"Infertility is the inability to conceive after one year of regular unprotected intercourse."
187
Causes of infertility
"Infertility can be caused by a variety of factors
188
Treatment of infertility
"Infertility can be treated with a variety of methods
189
Assisted reproductive technologies (ART)
"ART includes methods such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI)."
190
In vitro fertilization (IVF)
"IVF involves fertilizing eggs with sperm in a laboratory dish and then transferring the resulting embryos into the uterus."
191
Intracytoplasmic sperm injection (ICSI)
"ICSI involves injecting a single sperm directly into an egg."
192
Reproductive behaviour
"Reproductive behaviour is any behaviour that increases the chances of fertilization."
193
Types of reproductive behaviour
"Reproductive behaviour can include courtship
194
Courtship
"Courtship is the behaviour that precedes mating."
195
Purpose of courtship
"Courtship helps to ensure that individuals of the same species mate and that the female is receptive to mating."
196
Courtship signals
"Courtship can involve a variety of signals
197
Mating
"Mating is the act of copulation or insemination."
198
Parental care
"Parental care is any behaviour that increases the survival of offspring."
199
Forms of parental care
"Parental care can include nest building
200
Evolutionary significance of reproductive behaviour
"Reproductive behaviour is important for the survival of the species."
