01. EVOLUTION & LIFE'S DIVERSITY Flashcards
(114 cards)
Outline fission (asexual reproduction)
What: Splitting into 2+ equal parts
When: homogenous, stable environ
Who: all domains/kingdoms
Advantages
o Rapid replication
o Minimal E consumption
o Efficient + secure (X need to find mate)
Disadvantages
o Less genetic div → less able to adapt to changing/new environ
Example: bacteria
Outline budding (asexual reproduction)
What: parent cell div into 2 uneq parts
When: abundant nutrients parent grows too lg
Who: uni + multicell orgs from all domains + kingdoms
Advantages:
o Rapid replication
o Can occur anywhere on parent org (a/t some places more common than others)
Disadvantages:
o Less genetic div → less able to adapt to changing/new environ
Examples: hydra (animal) + yeast (fungi)
Outline fragmentation (asexual reproduction)
What: frag of parent org breaks off forms new org
When: w/ intention or stimulated by changing/new environ cond
Who: multicell orgs from all euk kingdoms
Advantages
o E efficient bc a) X have to find mate b) X need to devt sex orgs
o Secure bc X have to find mate
o Genetic clone → favourable traits retained
Disadvantages
o Less genetic div → less able to adapt to changing/new environ
Examples: planaria (flatworm)
Outline vegetative propogation (asexual reproduction)
What: part of parent plant used to grow new plant – via multi strats: runners, bulbs, tubers, suckers
When: when reprod orgs have devt + sep from other orgs (e.g. axillary bud grows + seps from lateral shoot devts indiv roots)
Who: multicell plantae orgs only
Advantages:
o E efficient bc a) X have to find mate b) X need to devt sex orgs
o Secure bc X have to find mate
o Genetic clone → favourable traits retained
Disadvantages
o Less genetic div → less able to adapt to changing/new environ
Examples: strawbs, garlic, potatoes
Outline parthenogenesis (a/sexual reproduction)
What: unfertilised egg devt into indiv (mostly remains dip org bc fertilised by mum thru reabsorbtion)
When: male X present
Who: multicell orgs from euk kingdom Animalia
Advantages:
o E efficient + secure bc X have to find mate
Disadvantages:
o Less genetic div → less able to adapt to changing/new environ
Examples: bees, ant, some fish/lizards
Compare the key features of asexual and sexual reproduction
Asex:
* req one parent org
* offspring = genetically identical to parent
* time/energy eff
* pop inc rapidly when conditions = optimal
Sexual:
* req two parents orgs
* offspring = hybrid of parents’ genes
* req time/energy to find mate
* inc genetic div -> inc pop resilience bc inc variation w/in pop that NS can act upon
Outline features of alternations of generations
- occurs in multicell protists, all land plants, some fungi
- alt bw hap + dip gens = both multicell
- dip form prod spores → hap form prod gametes
- gametes need to fuse w partner gamete to reprod vs spores don’t
Outline features of sexual reproduction in fungi
- process varies dep on species
- maj time in hap phase
- 3 stages = plasmogamy, karyogamy, meiosis
Outline features of reproduction via pollination
- 2 types = biotic + abiotic
- abiotic factors = wind, rain, water e.g. cedar tree, water plants
- biotic = attracts pollinators e.g. orchids scent mimic fem bees
Outline features of reproduction in angiosperms
stamen structures house sperm = contain genetic info
Draw a diagram of a generalised plant life cycle
Image 1
Why do organisms respire?
to release energy from food → fuel cell function
What is the difference between anaerobic and aerobic respiration?
aer resp uses O to extract E from food - anaer uses diff compound e.g. nitrate, sulfur instead
What are the benefits of aerobic + anaerobic respiration?
aerobic: release more ATP molecules → possibly enabled evolution of multicellularity + lg size orgs
anaerobic: releases E quickly + can occur in low O environs
Why is fermentation not considered respiration?
X use electron transport chain
How did respiration evolve?
early life respired anaerobicly bc X much O in atm
h/e emergence of photosynthetic bacteria ~3.5bn yrs ago created cond conducive for aerobic resp ~2.9bn yrs ago
What types of respiration (aerobic or anaerobic) do bacteria and fungi use?
bacteria = aer and/or anaer
fungi = mostly aer but occ anaer
How do fungi obtain oxygen in soil?
oxygen in tiny air spaces bw soil particles absorbed thru thin outer wall of hyphae (thin branching filamentous structure)
How are bacteria and fungi used to create food?
bacteria + fungi = core components of fermentation process = breaks down bacteria/yeast into starch/sugar
Why do all parts of the plant need to respire?
minimal gas exchange between parts - need to fulfill own resp needs indiv
How do plants obtain oxygen?
via diffusion thru stomata and lenticels
via absorption thru roots
How have plant roots adapted to meet respiration needs?
- aerial roots (pneumatophores)
- aerenchyma = sml air pockets w/in plant tissue → enabled oxygen flow from exposed to anoxic/waterlogged portion
How do stomata facilitate respiration?
open/close to allow gas exchange dep on environ factors - also dets stomata density/aperture
What are some different types of gas exchange in animals?
- direct diffusion
- integumentary exchange (across skin)
- trachea
- gills
- lungs
often depends on moisture lvl of environ e.g. integ exchange X conducive to dry environ bc skin X wet