Bio Exam Flashcards
what happens during metaphase?
chromosomes align at the equator of the cell
spindle fibres attach to centromeres
what happens during telophase?
genetic material is separated
the nuclear membrane is reformed
what happens during prophase?
centrioles migrate to opposite poles
what happens during anaphase
sister chromatids are drawn to opposite poles
processes that occur in humans which involve mitosis? (2)
growth
repair
structures in chromosome during early prophase? (2)
centromere
daughter chromosomes
stage in mitosis where chromosome is broken?
anaphase
functions of centromeres?
in metaphase they align along equator and in anaphase, they split and chromatids are drawn to poles
differences between binary fission and mitosis?
moving of chromosomes is different
(pro-cell membrane, euk-spindle fibres)
mitosis is broken down into stages
binary fission is quicker (don’t have to move as much stuff)
function of mitochondria
produces energy (ATP)
function of chloroplasts
sight of photosynthesis
why plant cells loose water when placed in a 10% salt solution? (3)
osmosis
concentration gradient
cell membrane moved away from wall
characteristics of daughter cells formed by mitosis?
genetically identical
what is osmosis?
refers to the movement of water molecules from a region of high concentration to low concentration through a semi-permeable membrane
eukaryotic cells possess both… (membranes)?
a cell membrane and nuclear membrane
similarities between lactic acid fermentation (anaerobic respiration) and alcoholic fermentation?
do not require oxygen
where do small molecules move?
passively between the phospholipid molecules (in cell membrane)
cellular structures that plant and animal cells have in common? (3)
mitochondria
lysosomes
golgi body
difference between smooth er and rough er?
presence of ribosomes on rough er but not smooth er.
how can a prokaryotic cell be identified?
absence of nucleus
what is facilitated diffusion?
the transport of small sugar molecules through the cell membrane.
mitotic cell division results in daughter cells with…?
identical genotypes and same number of chromosomes as the parent cell.
which stage of mitosis are the sister chromatids separated?
anaphase
chloride ions are transported across the membrane through carrier protein by…?
active transport
difference between plant and animal cell?
Plant cells have a cell wall, but animal cells do not. Cell walls provide support and give shape to plants. Plant cells have chloroplasts, but animal cells do not. Chloroplasts enable plants to perform photosynthesis to make food.
cells reproduce for growth and repair. compare the genetic content of the daughter cells produced in mitosis to the parent cell?
same number of chromosomes
before mitosis it doubles the genetic material
mitosis stages order
prophase, metaphase, anaphase, telophase
refer to fluid mosaic model, structure of cell membrane?
cell membrane controls what goes in and out of cell through protein channel.
proteins are embedded and are mosaic because there are so many different types.
process of exocytosis?
movement of material from low to high concentration
vesicle move to membrane and join (allows movement through membrane)
(vesicle are made up of lipids)
equation for photosynthesis?
sunlight
C6H12O6 + CO2 ——————-> H2O + O2
chlorophyll
Glucose + carbon dioxide –> water + oxygen
various types of organisms that live in the same suburban backyard. these organisms together make up…?
a community
Biotic factors are the living components of an ecosystem. They are sorted into three groups:…?
producers or autotrophs
consumers or heterotrophs
decomposers or detritivores.
a location where primary succession cannot occur?
a forest that has been destroyed by fire
homo erectus and homo sapiens belong to the…?
same genus but different species
genetic diversity is important as it ensures that a species can…? (3)
avoid inbreeding with members of the same species
resist disease
survive when the conditions of its environment are changed
adaptions? (3)
behavioural
structural
physiological
natural source of carbon dioxide emissions? (2)
plant/animal respiration
volcanic combustion
consequence of increasing carbon dioxide concentrations in the atmosphere?
enhanced green house effect
difference between habitat destruction and habitat fragmentation?
habitat destruction is the complete removal and deconstruction of the habitat/ecosystem that organisms occupy. habitat fragmentation is when the natural ecosystem is broken up into isolated patches.
why polar bear is keystone species?
it applies to the control of the population of (seals, whales, walrus, reindeer, rodents, seabirds, fish, and vegetation) in its ecosystem.
this prevents those population sizes from increasing to unsustainable levels which could disrupt the food web.
community?
the populations of different species interacting in the same place at the same time.
food chain example?
plant —> insect —> mouse —> owl
how can re-establishment of climax community occur after a fire?
climax community= An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.
there is existing soil after disturbance, colonising plant species can quickly grow.
which will be faster?
establishment of community on bare rock or re-establishment of habitat after logging.
re-establishment after logging.
because there is existing soil, there is rapid plant growth. the bare rock has no soil and this requires species like moss to form soil over many years.
trophic level of ecosystem is removed? what is this called?
trophic cascade
what type of species can sea otter, polar bear and elephants be defined as?
keystone species