ECE 1108 Final Flashcards
What allowed single multicellular organisms to evolve to complex multicellular organisms? (discussed this for the last test)
endosymbiotic theory
Characteristics of multicellularity:
The organism is larger. Cell differentiation. longer lifespan. More functions.
homology:
the state of having the same or similar relation, relative position, or structure
germ line mutations
any detectable variation within germ cells
somatic mutations
genetic alteration acquired by a cell that can be passed to the progeny of the mutated cell in the course of cell division
Prezygotic: isolation
prevents the fertilization of egg
postzygotic: isolation
mechanisms include habitat isolation, mating seasons, “mechanical” isolation, gamete isolation and behavioral isolation barriers and the different types of each
Endosymbiotic theory
endosymbiotic theory: prokaryotes ingested other prokaryotes and instead of ingesting them they became important to them and became mitochondria, chloroplasts, and other organs
Alternation of generations
alternating between the gametophye phase and the sporophyte phase
Double fertilization in angiosperms
- A pollen tube releases two sperm cells into an unfertilized ovule. 2: Double fertilization occurs when one sperm cell fuses with the egg to produce a zygote, and the other sperm cell fuses with the two polar nuclei to make the endosperm. 3: After double fertilization, a seed and fruit develop
Fungi – how do they eat?
Most fungi feed on the remains of dead plants and animals. Fungi are decomposers and change dead things into a humus which is rich in the nutrients that plant use as a food
C3 plant
Photosynthetic organisms that undergo a one stage process of C3 photosynthesis that begins the process of energy conversion, known as the Calvin cycle, by producing a three-carbon compound called 3-phosphoglyceric acid
C4 plant
a two stage process that produces a four-carbon intermediate compound
CAM plants
ganisms absorb sunlight energy during the day then use the energy to fix carbon dioxide molecules during the night.
What is vascular cambium
produces secondary xylem on the inside of the ring, and secondary phloem on the outside, pushing the primary xylem and phloem apart
Difference between primary and secondary growth in plants
The increase in length of the shoot and the root is referred to as primary growth. Secondary growth is characterized by an increase in thickness or girth of the plant
What processes allow water to move in a plant
xylem vessels
Explain nitrogen fixation
the chemical processes by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle
gibberillins
any of a group of plant hormones that stimulate stem elongation, germination, and flowering
auxin
a plant hormone that causes the elongation of cells in shoots and is involved in regulating plant growth
ethylene
stimulating or regulating the ripening of fruit
cytokinins
promote cell division
abscisic acid
a plant hormone that promotes leaf detachment, induces seed and bud dormancy, and inhibits germination
self-compatible
plant can fertilize itself
self-incompatible plant
plant rejects itself from fertilizing itself
fixed action pattern
is sometimes used in ethology to denote an instinctive behavioral sequence that is relatively invariant within the species and almost inevitably runs to completion
key stimulus
triggers an innate releasing mechanism (IRM), a sort of middleman, which produces a fixed action pattern (FAP), a definite, constant response
an invertebrate
an animal without a backbone
Vertebrate
an animal that has a backbone and a skeleton
gastrulation
phase early in the embryonic development of most animals, during which the single-layered blastula is reorganized into a multilayered structure known as the gastrula
cephalization
the concentration of sense organs, nervous control, etc., at the anterior end of the body, forming a head and brain, both during evolution and in the course of an embryo’s development. EX: flatworm
Advantage of amniotic eggs for terrestrial organisms:
he amniotic egg of reptiles and birds is surrounded by a tough outer shell that protects the egg from predators, pathogens , damage, and drying. The amnion keeps the embryo from drying out, so it’s critical to living on land
Meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores
keystone species
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically
