Reproduction Flashcards
(80 cards)
1
Q
what does natural selection select for?
A
genes that enables an organism to survive and reproduce
2
Q
what is reproduction?
A
Reproduction is the driving force of evolution
3
Q
what is asexual reproduction?
A
Single parent produces genetically identical cells through mitosis
Identical cells produced through mitosis from single parent
4
Q
Pros of asexual reproduction?
A
- No mate necessary
2. Genetically identical
5
Q
Cons of asexual reproduction?
A
Genetically identical
6
Q
what are the five types of asexual reproduction?
A
- binary fission
- budding
- vegetative reproduction
- fragmentation
- Parthenogenesis/Apomixis
7
Q
what is binary fission and where does it happen in most?
A
When one cell divides into two equal or nearly equal daughter cells
Happens in most single celled organisms
8
Q
what is budding?
A
An adult cell grows a smaller daughter cell from its own body
ex. Sponges
single and multicellular organisms
- all non-bilaterian taxa
9
Q
what is vegetative reproduction?
A
new individuals are created from parts of adults
10
Q
fragmentation
A
Occurs in simple animals (echinoderms, porifera, etc.)
11
Q
Parthenogenesis/Apomixis
A
Offspring born from unfertilized egg
12
Q
what is sexual reproduction?
A
two parents combine genetic information
only in eukaryotes
13
Q
Pros of sexual reproduction?
A
Genes are recombined to form an entirely new genome
14
Q
Cons of sexual reproduction?
A
- Must find a mate
2. Must undergo mating
15
Q
what do ciliates undergo in sexual reproduction?
A
conjugation
- Genes are transferred through a micronucleus
- Micronuclei fuse together to form a new genome
16
Q
what is fertilization?
A
- Where two cells fuse into one
2. Most multicellular organisms produce haploid gametes
17
Q
what do most multicellular organisms produce?
A
Most multicellular organisms produce haploid gametes
- “+” and “-”
- sperm and egg
- produce the diploid zygote
- Develops by mitosis into a new multicellular organism
18
Q
what is dioecious?
A
- Organism that produces only one type of gamete
2. male/female
19
Q
what is monoecious?
A
- Organism that produces both types of gametes
- Hermaphroditic
- May or may not self fertilize
20
Q
what are spores?
A
- Cells dispersed for breeding purposes
2. May form from sexual or asexual processes
21
Q
what are spores always?
A
Are ALWAYS haploid
22
Q
what are the two types of life cycles?
A
- Diplontic life cycle
2. Haplodiplontic life cycle
23
Q
what is the Diplontic life cycle?
A
- Only the diploid stage is multicellular
2. Haploid stage is one gamete cell
24
Q
what Is the Haplodiplontic life cycle?
A
- Multicellular diploid stage = Sporophyte
2. Multicellular haploid stage = Gametophyte
25
what characteristics do chlorophytes and charophytes both have?
1. Haplodiplontic life cycle
2. Gametophyte and sporophyte appear identical
3. +/- gametes
26
what are the characteristics of brown algae?
1. Haplodiplontic life cycle
2. Gametophyte is reduced
3. Sporophyte is dominant
4. Egg and sperm
27
what are the characteristics of bryophytes?
1. Haplodiplontic
2. Gametophyte is dominant:
- ---Archegonia – Female
- ---Antheridia – Male
28
what happens bryophytes after fertilization?
After fertilization:
- -Archegonia grows a sporophyte stalk
- -Sporophyte produces spores and is non-photosynthetic
29
what are the characteristics of pteridophytes?
1. Haplodiplontic
| 2. Sporophyte dominant
30
in pteridophytes what happens in the sporophyte cycle?
1. produce sori on the back of the fronds
2. Small gametophyte with antheridia and archegonia
- --The gametophyte is free living and photosynthetic
3. Sperm fertilizes egg and a sporophyte grows from archegonium
31
what are the characteristics of seed plants?
1. Haplodiplontic
2. Seed plants produce 2 kinds of gametophytes
- -- male and female gametophytes
32
what are the two kinds of gametophytes in seed plants and they do?
1. Male gametophytes = microgametophyte
- -Pollen grains
- -Dispersed by wind or a pollinator
2. Female gametophytes = megagametophyte
- -Develop within an ovule
- -Enclosed within diploid sporophyte tissue
33
what happens in gymnosperms?
1. Sporophyte produces male and female cones
- -Pollen grains develop in male cones by meiosis
- -Female cones are larger, and have woody scales
2. scales of female cone are open, pollen grains drift down between them
3. pollen tube emerges from the pollen grain
- -digests its way to the embryo sac
- -Delivers sperm
- -Fertilization
34
what does angiosperms possess?
possess flowers and fruit?
35
what does the flower structure contain?
1. Floral organs--which are thought to have evolved from leaves
2. complete flower
3. incomplete flower
36
what is the structure of flowers?
Calyx
Corolla
Androecium
Gynoecium
37
Calyx
Consists of sepals
38
Corolla
Consists of petals
39
Androecium
- -Collective term for stamens
| - -A stamen consists of a filament and an anther
40
Gynoecium
- -Collective term for carpels
| - -A carpel consists of an ovule, ovary, style, and stigma
41
what does a complete flower have?
A complete flower has four whorls
42
what does an incomplete flower have?
incomplete flower lacks one or more of these whorls
43
how are gamete produced?
Gametes are produced in separate, specialized structures
44
what is a microgametophyte?
Four microspores that form through meiosis and become pollen grains
45
what does each microgametophyte consist of?
Each consist of:
1. Tube cell
2. Generative cell that will later divide to two sperm cells
46
what are the 8 haploid nuclei in megagametophyte?
- egg
- 2 synergids
- 2 polar nuclei
- 3 antipodals
47
what is pollination?
Pollination is the process by which pollen is placed on the stigma
48
what are the two types of pollination and what are they?
1. Self-pollination
- --Pollen from a flower’s anther pollinates stigma of the same flower
2. Cross-pollination
- --Pollen from anther of one flower pollinates another flower’s stigma
49
what are the pollinators?
1. Bees
2. Butterflies
3. Birds
50
Bees
- -Most common insect pollinatiors
| - -Nectar guides
51
Butterflies
--Prefer flowers that have flat “landing platforms”
52
Birds
- -Like red flowers
| - -Usually inconspicuous to insects
53
what is wind pollination?
- -small, green, and odorless
- -Often grouped and hanging down in tassels
ex. grass, corn
54
what happens in fertilization?
1. Angiosperms undergo a unique process called double fertilization
- -Tube cell forms a pollen tube
- -generative cell divides to form 2 sperm cells
2. One sperm cell fuses with the egg cell to form the diploid (2n) zygote
- -Other sperm cell nucleus fuses with the two polar nuclei to form the triploid (3n) endosperm
- --->nourishes embryo
55
how does fertilization happen on fungi?
1. fertilization simply by merging hyphae cells from two individuals
- -nuclei fusion in a process called karyogamy, forming a diploid (2n) zygote
- -Sometimes forms a dikaryotic cell (1n+1n) before karyogamy
56
what is karyogamy and what does it form?
- nuclei fusion in a process
| - forms a diploid (2n) zygote
57
what is a dikaryotic cell?
(1n+1n) or n+n
58
what are the types of internal fertilization?
Oviparity, Ovoviviparity, and Viviparity
59
Oviparity
Fertilized eggs are deposited outside mother’s body to complete their development
60
Ovoviviparity
Fertilized eggs are kept within mother to complete development, and young obtain food from egg yolk
61
Viviparity
Young develop within mother and obtain nourishment from her blood
62
what are the aquatic vertebrates and what type of fertilization do they undergo?
1. Cartilaginous fish
- -fertilization is internal
- -Viviparous, ovoviviparous, and oviparous
2. Bony fish and most amphibians
- -fertilization is external
63
what are amniotes?
Animals with an amniotic egg
64
what are the characteristics of an amniotic egg?
1. The amniotic egg has four membranes
2. Water tight
3. Results from internal fertilization
65
what is the reproductive cycle of reptiles and birds?
1. Most reptiles and birds are oviparous
- -Lay amniotic eggs
- -Birds incubate the egg to keep it warm
2. Most male reptiles use a penis to inject sperm into females
- -Copulation
66
what is the reproductive cycle of mammals?
1. Female reproductive cycles involve periodic release of a mature egg (ovulation)
2. Most female mammals have estrous cycles
- -Females are receptive to males only around ovulation (estrus)
3. Primates have menstrual cycles
- -shedding inner lining of the uterus (menstruation)
- -Can copulate at any time in their cycle
67
what is menstruation?
shedding inner lining of the uterus
68
what type of fertilization do monotremes mammals undergo?
Monotremes are oviparous
| --Lay amniotic eggs
69
what type of fertilization do marsupial mammals undergo?
Marsupials are viviparous
| --Give birth to incompletely developed fetuses, which mature in mother’s pouch
70
what type of fertilization do placental mammals undergo?
Placental's are viviparous
| --Retain young in uterus for long periods of development
71
where did fertilization evolve?
Evolved in the ocean before animals colonized land
72
what are the types of fertilization?
External fertilization and Internal fertilization
73
External fertilization
1. Eggs and sperm are released into the water where union of free gametes occurs
2. Most aquatic organisms do this
74
Internal fertilization
Sperm are introduced into the female reproductive tract
75
what life cycle do animals undergo?
Diplontic
| Most reproduce only sexually
76
Basidiomycota
1. Spore germination leads to the production of haploid mycelium
2. Mycelium may fuse
3. Dikaryotic basidiocarp has hundreds of basidia in each gill
77
what happens when mycelium in fuse in Basidiomycota
1. Results in fertilization
2. Now dikaryotic
3. Basidiocarps (mushrooms) form from secondary mycelium
78
each gill in dikaryotic basidiocarp?
1. Club-shaped sexual reproductive structure
2. Karyogamy occurs within the basidium, and meiosis follows
3. Four haploid basidiospores result (each basidium 4 haploid cells)
79
what is the difference between pollination and fertilization?
```
Pollination = pollen on stigma
Fertilization = pollen tube grows all the way
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80
what is the difference between Diplontic and Haplodiplontic cycle?
```
Haplodiplontic
1. multicellular stage (diplontic and haploid stage)
2. equal diplontic and haploid stage
Diplontic
1. single celled things that are haploid
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