Lect 25 Flashcards
1
Q
What is sexual reproduction?
A
Sexual reproduction is a process where all kingdoms of the eukarya have species with meiotic sex.
2
Q
What does LECA stand for?
A
LECA stands for the last eukaryotic common ancestor.
3
Q
Did the last eukaryotic common ancestor (LECA) have meiotic sex?
A
Yes, LECA had meiotic sex.
4
Q
What type of reproduction did LECA predominantly use?
A
LECA predominantly reproduced by mitosis.
5
Q
True or False: LECA was a multicellular organism.
A
False
6
Q
Fill in the blank: LECA was a _______ organism.
A
single celled
7
Q
What did the Last Eukaryotic Common Ancestor (LECA) have?
A
The Last Eukaryotic Common Ancestor (LECA) likely had both mitochondria and a nuclear genome.
LECA is the most recent common ancestor of all eukaryotic organisms.
8
Q
What is Saccharomyces cerevisiae commonly known as?
A
Brewer’s yeast
Also used in making bread.
9
Q
What type of organism is Saccharomyces cerevisiae?
A
Haploid single celled organism
10
Q
How does Saccharomyces cerevisiae reproduce asexually?
A
By mitotic cell divisions - by budding
11
Q
What happens in Saccharomyces cerevisiae in response to starvation?
A
Two haploid cells can fuse to form a transient diploid cell
12
Q
Is the fusion of haploid cells in Saccharomyces cerevisiae obligatory?
A
No, not all cells do this, it is not obligatory
13
Q
What occurs immediately after the formation of the diploid cell in Saccharomyces cerevisiae?
A
The diploid immediately enters meiosis and produces 4 haploid cells
14
Q
Is meiotic sex required for the reproduction of Saccharomyces cerevisiae?
A
No, meiotic sex is not required
15
Q
Can Saccharomyces cerevisiae reproduce indefinitely without sex?
A
Yes
16
Q
What are modern higher eukaryotes?
A
Multicellular organisms that include plants and animals
17
Q
What types of cells do modern higher eukaryotes have?
A
Distinct soma and germline cells
18
Q
What is the ploidy level of soma and germline cells in modern higher eukaryotes?
A
Diploid
19
Q
What process creates haploid gametes from germline stem cells?
A
Meiosis
20
Q
What is formed when sperm and egg (or pollen and ovule) fuse?
A
Diploid zygote
21
Q
What process allows for the clonal expansion of cells to create a new organism?
A
Mitosis
22
Q
Does sexual reproduction occur between every generation of multicellular organisms?
A
Yes
23
Q
True or False: All animals and plants reproduce sexually.
A
False
24
Q
What type of reproduction do some organisms use instead of sexual reproduction?
A
Asexual systems
25
From what type of species did modern asexual eukaryotes evolve?
An earlier sexual species
26
What is the significance of the last eukaryotic common ancestor in relation to sexual reproduction?
It indicates that all eukaryotes had sex
27
What is the basis of eukaryotic sexual reproduction?
Meiosis
## Footnote
Meiosis is a type of cell division that reduces the chromosome number by half and is fundamental for sexual reproduction in eukaryotes.
28
Which domain of life has meiotic sex?
Eukarya
## Footnote
Only eukaryotes are known to reproduce sexually through meiosis.
29
Do any kingdoms other than Eukarya have meiotic sex?
No
## Footnote
Other kingdoms evolved from asexual ancestors and remain asexual.
30
Can eukaryotes evolve into asexual species?
Yes
## Footnote
Some eukaryotes have evolved into asexual species multiple times throughout their evolutionary history.
31
What type of reproduction do most higher eukaryotes use?
Sexual reproduction
## Footnote
Asexual methods are not uncommon among higher eukaryotes.
32
Can most higher eukaryotes that reproduce asexually also reproduce sexually?
Yes
## Footnote
This indicates flexibility in reproductive strategies.
33
How common is obligate asexual reproduction among higher eukaryotes?
Very uncommon
## Footnote
Most higher eukaryotes have the capability for sexual reproduction.
34
What is fission?
Division into two equally-sized offspring
## Footnote
Fission is a form of asexual reproduction commonly seen in unicellular organisms.
35
What is budding?
Unequal division resulting in a smaller offspring
## Footnote
Budding is often observed in organisms like yeast and hydra.
36
What is fragmentation?
Parent breaks into many small new individuals
## Footnote
Fragmentation is a type of asexual reproduction where a single parent organism breaks into parts, each capable of growing into a new individual.
37
What type of reproduction can sea anemones, Kalanchoe, and hydra undergo?
Asexually under certain conditions, but they may also reproduce sexually
## Footnote
Asexual reproduction allows organisms to reproduce without the fusion of gametes, while sexual reproduction involves the combination of genetic material from two parents.
38
Fill in the blank: Sea anemones, Kalanchoe, and hydra can all reproduce _______ under certain conditions.
asexually
39
Name one organism that can reproduce both asexually and sexually.
Sea anemones, Kalanchoe, or hydra
## Footnote
Each of these organisms has the ability to switch between reproductive methods depending on environmental conditions.
40
What is the reproductive cycle of Daphnia called?
Cyclical parthenogenesis
## Footnote
This process involves switching between asexual and sexual reproduction based on environmental conditions.
41
During which seasons do Daphnia reproduce asexually?
Spring and summer
## Footnote
These seasons provide favorable conditions for rapid reproduction.
42
How do female Daphnia reproduce asexually?
Through parthenogenesis
## Footnote
In this process, females produce diploid (2n) eggs without fertilization.
43
What type of offspring do asexual Daphnia produce?
Genetically identical female clones
## Footnote
This allows for rapid population growth.
44
What triggers Daphnia to switch to sexual reproduction?
Deteriorating conditions in autumn
## Footnote
Factors include food scarcity or temperature drops.
45
What type of males develop in the sexual reproduction phase of Daphnia?
Haploid (n) males
## Footnote
These males produce sperm.
46
What type of eggs do female Daphnia produce during sexual reproduction?
Haploid (n) ova
## Footnote
These ova are fertilized by sperm to form diploid eggs.
47
What is the outcome of fertilization between Daphnia gametes?
Diploid, hard-shelled eggs or cysts
## Footnote
These cysts remain dormant through winter.
48
What is the purpose of the dormant cysts produced by Daphnia?
To ensure survival during harsh conditions
## Footnote
This allows Daphnia to survive until favorable conditions return.
49
What happens to the cysts when the environment becomes favorable again?
They hatch, restarting the asexual cycle
## Footnote
This process enables quick reproduction once conditions improve.
50
What type of reproduction do dandelions use?
Obligate asexual reproduction by apomixis
51
What is apomixis?
The plant form of parthenogenesis
52
Are dandelion flowers sexual or asexual?
Asexual
53
What are eggs referred to in plants?
Ovules
54
What is the ploidy level of dandelion ovules?
Diploid
55
Do dandelion ovules undergo meiosis?
No
56
Do dandelion ovules require pollen for development?
No
57
What do ovules develop into in dandelions?
Seeds
58
How are dandelion seeds disseminated?
Wind disseminated
59
What is parthenogenetic reproduction?
Asexual reproduction without the need for males
## Footnote
In this process, females produce offspring by laying eggs that develop without fertilization, effectively cloning themselves.
60
Which genus of lizards is known for parthenogenetic reproduction?
Aspidoscelis
Whiptail lizards belong to this genus.
61
Do whiptail lizards engage in mating behaviors despite being entirely female?
Yes
## Footnote
One female may mount another, which appears to stimulate the production of eggs.
62
What role does estradiol play in the reproductive cycles of many reptiles?
Regulates reproductive cycles
## Footnote
It helps control the development of eggs in the ovaries and stimulates the growth of reproductive tissues.
63
Is ovulation necessary for the parthenogenetic reproduction of whiptail lizards?
No
## Footnote
Parthenogenetic reproduction does not require ovulation in the typical sense.
64
What hormone is involved in triggering egg development in whiptail lizards?
Estradiol
## Footnote
It is involved similarly to how it works in species that undergo sexual reproduction.
65
Fill in the blank: Estradiol is a form of _______ that helps control the development of eggs.
estrogen
66
True or False: Estradiol is only involved in species that undergo sexual reproduction.
False
## Footnote
Estradiol is also involved in the egg development of parthenogenetic species.
67
What does estradiol help prepare in species that undergo ovulation?
Ovaries and reproductive system
## Footnote
It prepares these for egg release, making it essential for reproductive processes.
68
What type of eggs do whiptails have?
2n eggs - NO sperm, NO meiosis.
69
What is the sequence of development in whiptails?
2n adult => 2n ova > 2n embryos => 2n adults.
70
What role does pseudo-mating play in whiptails?
Promotes ovulation.
71
What are the hormone levels and ovary size on top during the reproductive cycle?
Estradiol low & progesterone high; small ovary.
72
What changes occur on the bottom during the reproductive cycle?
Estradiol high, ovary increase in size and ovulate.
73
What is a genus in biological classification?
A taxonomic rank that groups together species that are closely related.
## Footnote
Genus is part of the hierarchy in taxonomy, which includes ranks such as kingdom, phylum, class, order, family, genus, and species.
74
What does phylogeny refer to?
Evolutionary descent with reflected levels of genetic similarity.
## Footnote
Phylogeny involves the study of the evolutionary relationships among biological entities, often depicted as a tree.
75
What do all members of one genus share?
A more closely related common ancestor than any member of a different genus.
## Footnote
This relationship highlights the importance of evolutionary history in biological classification.
76
What is the only level at which obligate asexual reproduction is found?
At the level of individual isolated species within an otherwise sexual genus
## Footnote
This indicates that obligate asexual species do not form a genus with multiple species.
77
True or False: There is a eukaryotic genus of multiple obligate asexual species.
False
## Footnote
Obligate asexual species exist only as individual species.
78
What are the two mating types of yeast?
'a' and 'α'
## Footnote
Yeast has two mating types instead of distinct sexes.
79
Can an 'a' yeast cell fuse with another 'a' cell?
No, only an 'a' can fuse with an 'α/ alpha'
## Footnote
This specificity drives outbreeding in yeast.
80
What typically happens to daughter cells in yeast regarding mating types?
They usually express the same mating type as their mother cell.
81
How do animal sexes differ from yeast mating types?
Animal sexes evolved separately from yeast mating types.
82
What do higher plants involve in terms of sexes?
Pollen and ovules
## Footnote
Higher plant sexes also evolved separately from animal sexes.
83
What is anisogamy?
One big gamete and one small gamete has evolved independently several times
84
In which organisms has anisogamy evolved independently?
* Land plants
* Some red, brown, and green algae
* Malaria parasites
85
What is one benefit of having different sexes in organisms?
Promotes outbreeding and prevents selfing.
86
What does R of 1 indicate about population change?
Population stays the same per generation (x 1)
## Footnote
R of 1 implies no growth or decline in population size.
87
What does R of 2 indicate about population change?
Population doubles per generation (x 2)
## Footnote
R of 2 signifies exponential growth in population size.
88
What is the R number for asexual reproduction?
2
89
What is the R number for sexual reproduction?
1
90
What are the two roles in sexual reproduction?
* Female ‘reproducer’
* Male ‘sperm provider’
91
True or False: All individuals are considered ‘reproducers’ in asexual reproduction.
True
92
Fill in the blank: Female ‘reproducer’ plus male ‘sperm provider’ equals _______.
sexual reproduction
93
Fill in the blank: In asexual reproduction, all individuals are ‘_______’.
reproducers
94
What is a key biological cost of sexual reproduction?
Requires two individuals to reproduce
## Footnote
This increases the complexity and energy expenditure compared to asexual reproduction.
95
How many offspring does a female need to produce compared to an asexual reproducer?
Twice as many offspring
## Footnote
This is necessary to offset the costs associated with finding a mate.
96
What is a significant challenge in sexual reproduction?
Locating a mate
## Footnote
This involves complex behavior to find the correct mate of the correct species and sex.
97
What anatomical differences are required for sexual reproduction?
Two different gametes from two different gonads
## Footnote
Differences vary between species, such as birds versus mammals.
98
What encodes the anatomical differences between sexes?
A single genome
## Footnote
These differences are not encoded by the Y chromosome.
99
What must both sexes do during evolution for successful reproduction?
Co-evolve
## Footnote
This involves compatible behaviors, anatomies, and cell biology.
100
True or False: Sexual reproduction is less costly than asexual reproduction.
False
## Footnote
Sexual reproduction involves more complex processes and energy expenditure.
101
Fill in the blank: A female engaging in sexual reproduction must produce _______ as many offspring as an asexual reproducer.
twice
## Footnote
This is to compensate for the costs of sexual reproduction.
102
Which version of chromosome 1 does the child get from their mother?
Either Ch1 from maternal grandfather or Ch1 maternal grandmother
## Footnote
True for all autosomes; sex chromosomes are slightly different.
103
What process allows for the independent assortment of chromosomes?
Meiosis
104
From how many grandparents can a child's chromosomes potentially come?
2 parents, 4 grandparents, 8 great-grandparents, and so on
## Footnote
Going back 10 generations results in chromosomes from 1,024 different great-great-great-great... etc grandparents.
105
What is crossing over in the context of meiosis?
Recombination between homologous chromosomes
106
What type of chromosomes does a child receive from their mother?
A hybrid of maternal grandfather and maternal grandmother origin
107
What are the two orders of genome shuffling provided by meiosis?
* Independent assortment of chromosomes
* Crossing over between homologous chromosomes
108
What is the consequence of giving up sex in evolutionary terms?
An evolutionary dead end
## Footnote
This explains the phylogenetic isolation of obligate asexual species.
109
What does the phylogenetic isolation of obligate asexual species indicate?
It indicates that these species cannot evolve further due to lack of sexual reproduction.
110
True or False: Sex is essential for evolution.
True
111
Fill in the blank: Giving up sex explains the _______ isolation of obligate asexual species.
phylogenetic
112
What is the main advantage of asexual reproduction?
It is simple and less likely to fail in any one generation.
113
What is not required in asexual reproduction?
Finding a mate.
114
How does sexual reproduction promote genetic variation?
It is coupled to diploidy and promotes genetic variation in the genome of a species.
115
How do the offspring of sexual reproduction compare to their parents?
Offspring are NEVER genetically identical to parents.
116
Fill in the blank: Asexual reproduction leads to _______ offspring.
clonal
117
True or False: Offspring from asexual reproduction are genetically identical to their parents.
True
118
What is a common characteristic of aspen trees in terms of their growth?
Aspen trees often grow in a 'grove' from the root system of a founder tree.
## Footnote
This characteristic allows for the formation of large areas of genetically identical trees.
119
How do new saplings of aspen trees sprout?
New saplings sprout from somatic tissue of the parent root.
## Footnote
This process is similar to taking cuttings from a plant.
120
What type of reproduction do aspen trees utilize?
Aspen trees utilize asexual reproduction.
## Footnote
This means they reproduce without sexual reproduction or meiosis.
121
What is a grove of aspen trees considered in terms of genetic identity?
The grove is considered a somatic 'clone'.
## Footnote
This indicates that all trees in the grove are genetically identical.
122
Fill in the blank: Aspen trees reproduce through _______.
asexual reproduction
123
True or False: Aspen trees reproduce sexually through meiosis.
False
## Footnote
Aspen trees reproduce asexually, not sexually.
