BIO1108 EXAM 2 QUESTIONS
WITH CORRECT DETAILED
ANSWERS
how do bacteria play a role in the carbon cycle - Answer- decay, photosynthesis,
respiration; methanogens are archaea
evidence of endosymbiosis - Answer- -double-walled membranes (found in
chloroplasts)
-contain DNA/RNA
-contain 70S ribosomes
-ATP production via a proton gradient
-electron transport chains (thylakoid membrane in chloroplasts, cristae of mitochondria)
-self-replicate
what kind of bacteria was consumed in endosymbiosis? - Answer- aerobic bacteria;
purple-sulfur or cyanobacteria
three eukaryote phyla - Answer- fungi, animals, and plants
colonial multicellularity - Answer- groups of identical cells form masses
complex multicellularity - Answer- differentiation of gametes and other tissues
what is necessary for multicellularity to occur? - Answer- multiple gene expression,
communication system, stick together, cell differentiation, specialized repro cells (if
needed)
common genes b/w protozoans and choanoflagellates - Answer- signaling, adhesion,
and gene regulation
algae - Answer- example of a unicellular plant (protist)
adaptations of plants for water loss/gas exchange - Answer- -stomata & guard cells
(swell=open; deflate=close)
-waxy cuticle
Adaptations of plants for UV light - Answer- -UV absorbing pigments (carotenoids &
chlorophylls)
-alteration of generations
, xylem - Answer- only carries WATER in the UP direction
phloem - Answer- carries dissolved nutrients and hormones up AND down plant; moves
through osmotic pressure
adaptations for reproduction in plants - Answer- -fertilization
-spore/seed dispersal
naked gametes - Answer- release sperm/eggs into water and hope they find one
another
pollen - Answer- contains sperm; moved by wind or animals
cotyledon - Answer- food storage as fats and oils
relationship between seed size and fecundity - Answer- negative; as seed size
increases, fecundity decreases
relationship between seed size & survivorship - Answer- positive relationship; larger
seed can store more food in the cotyledon
when did life begin - Answer- 4 BYA
when did photosynthesis begin - Answer- 3.5 BYA
Cambrian explosion date - Answer- 530 MYA
permian extinction date - Answer- 251 MYA
cretaceous extinction date - Answer- 65 MYA
what is the Cambrian explosion - Answer- sudden increase in marine animal life
% of species lost in permian extinction - Answer- 95% of all species on earth were lost
what caused the permian extinction - Answer- changes in atmospheric/oceanic
chemistry
% of species lost in cretaceous extinction - Answer- 75% of all species lost
most likely cause of cretaceous explosion - Answer- asteroid strike
how do we know what caused the cretaceous extinction - Answer- KT boundary aka a
layer of iridium rock in the earth's surface
the cretaceous extinction started the.... - Answer- age of mammals
WITH CORRECT DETAILED
ANSWERS
how do bacteria play a role in the carbon cycle - Answer- decay, photosynthesis,
respiration; methanogens are archaea
evidence of endosymbiosis - Answer- -double-walled membranes (found in
chloroplasts)
-contain DNA/RNA
-contain 70S ribosomes
-ATP production via a proton gradient
-electron transport chains (thylakoid membrane in chloroplasts, cristae of mitochondria)
-self-replicate
what kind of bacteria was consumed in endosymbiosis? - Answer- aerobic bacteria;
purple-sulfur or cyanobacteria
three eukaryote phyla - Answer- fungi, animals, and plants
colonial multicellularity - Answer- groups of identical cells form masses
complex multicellularity - Answer- differentiation of gametes and other tissues
what is necessary for multicellularity to occur? - Answer- multiple gene expression,
communication system, stick together, cell differentiation, specialized repro cells (if
needed)
common genes b/w protozoans and choanoflagellates - Answer- signaling, adhesion,
and gene regulation
algae - Answer- example of a unicellular plant (protist)
adaptations of plants for water loss/gas exchange - Answer- -stomata & guard cells
(swell=open; deflate=close)
-waxy cuticle
Adaptations of plants for UV light - Answer- -UV absorbing pigments (carotenoids &
chlorophylls)
-alteration of generations
, xylem - Answer- only carries WATER in the UP direction
phloem - Answer- carries dissolved nutrients and hormones up AND down plant; moves
through osmotic pressure
adaptations for reproduction in plants - Answer- -fertilization
-spore/seed dispersal
naked gametes - Answer- release sperm/eggs into water and hope they find one
another
pollen - Answer- contains sperm; moved by wind or animals
cotyledon - Answer- food storage as fats and oils
relationship between seed size and fecundity - Answer- negative; as seed size
increases, fecundity decreases
relationship between seed size & survivorship - Answer- positive relationship; larger
seed can store more food in the cotyledon
when did life begin - Answer- 4 BYA
when did photosynthesis begin - Answer- 3.5 BYA
Cambrian explosion date - Answer- 530 MYA
permian extinction date - Answer- 251 MYA
cretaceous extinction date - Answer- 65 MYA
what is the Cambrian explosion - Answer- sudden increase in marine animal life
% of species lost in permian extinction - Answer- 95% of all species on earth were lost
what caused the permian extinction - Answer- changes in atmospheric/oceanic
chemistry
% of species lost in cretaceous extinction - Answer- 75% of all species lost
most likely cause of cretaceous explosion - Answer- asteroid strike
how do we know what caused the cretaceous extinction - Answer- KT boundary aka a
layer of iridium rock in the earth's surface
the cretaceous extinction started the.... - Answer- age of mammals
