SNAB Edexcel Biology AS Topic 4
a higher proportion of heterozygotes in a population means - ANS - the population has
greater genetic diversity
\Advantages of making rope from sustainable resources - ANS - renewable so more can
be grown
\allele frequency - ANS - how often an allele occurs in a population
\Anatomical adaptations - ANS - structural features of an organism's body that increase
its chance of survival
\Behavioural adaptations - ANS - ways an organism acts that increase its chance of
survival.
\Behavioural changes (reproductive isolation) - ANS - a group of individuals develop
courtship rituals that aren't attractive to the main population
\Binomial system - ANS - first word is the genus name and the second word is the
species name.
\Biodiversity - ANS - the variety of living organisms in an area. includes species diversity
and genetic diversity
\Cons of seedbanks - ANS - testing the seeds for viability is expensive and time
consuming, too expensive to store all types of seed and regulary test them, difficult to
collect seeds from plants as they grow in remote locations
\Conservation - ANS - protection and management of endangered species
\Description and function of the amyloplast - ANS - small organelle enclosed by a
membrane. stores starch granules and converts the starch back to glucose for release
when the plant requires it
\Description and function of the cell wall - ANS - rigid structure, mainly made of cellulose,
that surrounds and supports plant cells.
\Description and function of the chloroplast - ANS - small flattened structure. has a
double membrane and membranes inside called thylakoid membranes. thylakoid
membranes are stacked up in some parts to form grana. grana are linked together by
lamellae (thin pieces of thylakoid membrane). Site of photosynthesis
\Description and function of the middle lamella - ANS - outermost layer of the cell. acts as
an adhesive, sticking adjacent plant cells together. it gives the plant stability
\Description and function of the pits - ANS - regions in the cell wall where the wall is very
thin. arranged in pairs so a pit in one cell is lined up with the pit in the adjacent cell.
allows transport of substances between cells
\Description and function of the plasmodesmata - ANS - channels in the cell walls that
link adjacent cells together, allows transport of substances and communication between
cells
\Description and function of the vacuole and tonoplast - ANS - vacuole is a compartment
surrounded by a membrane called a tonoplast. vacuole contains cell sap which is made
up of water, enzymes, minerals and waste products. vacuoles keep cells turgid - stops
, plants from wilting. also involved in the breakdown and isolation of unwanted chemicals
in the cell. tonoplast controls what enters and leaves vacuole
\disadvantage of making ropes from plant fibres - ANS - they are not as strong as ropes
made of plastic
\Double blind study deisgn - ANS - neither the doctors nor the patients know who has
been given the new drug or the placebo/old drug. this reduces bias in results as the
attitudes of the patients and doctors can't affect the results
\Endemism - ANS - when a species is unique to a single place
\Function of phloem tissue - ANS - transport organic solutes from where they are made in
the plant to where they are needed . this is translocation
\Function of schlerenchyma fibres - ANS - provide support
\Function of xylem vessels - ANS - transports water and mineral ions up the plant and
provides support
\gene pool - ANS - complete set of alleles in a species
\Genetic diversity - ANS - the variation of alleles in the gene pool of a species
\Genetically distinct - ANS - the individuals from the different populations will have
changed so much that they won't be able to successfully breed with each other to
produce fertile offspring
\Geographical isolation - ANS - when a physical barrier divides a population of a species
\Heterozygote - ANS - have two different alleles at a particular locus
\How are seeds selected for storage - ANS - from different plants to provide genetic
variation. x rayed to check for viability
\How are the xylem vessels, phloem tissue and sclerenchyma fibres arranged in plant
stems - ANS - the xylem vessels and phloem tissue group together to form vascular
bundles. the sclerenchyma fibres are associated with the vascular bundles.
\How can looking at genotype help to measure genetic diversity of a species - ANS -
analyse the sequence of base pairs in DNA samples of organisms. the order of bases in
different alleles is slightly different. by sequencing the DNA of individuals of the same
species, you can look at similarities and dfferences in the alleles. The larger the number
of dif alleles the greater the genetic diversity
\How can looking at phenotype help to measure genetic diversity of a species - ANS -
different phenotypes are coded for by different alleles, so the larger the number of
different phenotypes, the greater the diversity of alleles so the greater the genetic
diversity
\How can using plant fibres contribute to sustainability - ANS - less fossil fuel is used up
and crops can be regrown to maintain the supply for future generations. products are
biodegradable. plants are easier to grow and process than extracting and processing oil
so they are cheaper and easier to do in developing countries, as less technology and
expertise is needed
\How can using starch contribute to sustainability - ANS - making plastics (bioplastics)
and vehicle fuel (bioethanol) from starch is more sustainable as less fossil fuels are used
up crops can be regrown.
\How can zoos and seedbanks help to educate people about conserving biodiversity -
ANS - helps to raise public awareness and interest. as people get close to the organisms
a higher proportion of heterozygotes in a population means - ANS - the population has
greater genetic diversity
\Advantages of making rope from sustainable resources - ANS - renewable so more can
be grown
\allele frequency - ANS - how often an allele occurs in a population
\Anatomical adaptations - ANS - structural features of an organism's body that increase
its chance of survival
\Behavioural adaptations - ANS - ways an organism acts that increase its chance of
survival.
\Behavioural changes (reproductive isolation) - ANS - a group of individuals develop
courtship rituals that aren't attractive to the main population
\Binomial system - ANS - first word is the genus name and the second word is the
species name.
\Biodiversity - ANS - the variety of living organisms in an area. includes species diversity
and genetic diversity
\Cons of seedbanks - ANS - testing the seeds for viability is expensive and time
consuming, too expensive to store all types of seed and regulary test them, difficult to
collect seeds from plants as they grow in remote locations
\Conservation - ANS - protection and management of endangered species
\Description and function of the amyloplast - ANS - small organelle enclosed by a
membrane. stores starch granules and converts the starch back to glucose for release
when the plant requires it
\Description and function of the cell wall - ANS - rigid structure, mainly made of cellulose,
that surrounds and supports plant cells.
\Description and function of the chloroplast - ANS - small flattened structure. has a
double membrane and membranes inside called thylakoid membranes. thylakoid
membranes are stacked up in some parts to form grana. grana are linked together by
lamellae (thin pieces of thylakoid membrane). Site of photosynthesis
\Description and function of the middle lamella - ANS - outermost layer of the cell. acts as
an adhesive, sticking adjacent plant cells together. it gives the plant stability
\Description and function of the pits - ANS - regions in the cell wall where the wall is very
thin. arranged in pairs so a pit in one cell is lined up with the pit in the adjacent cell.
allows transport of substances between cells
\Description and function of the plasmodesmata - ANS - channels in the cell walls that
link adjacent cells together, allows transport of substances and communication between
cells
\Description and function of the vacuole and tonoplast - ANS - vacuole is a compartment
surrounded by a membrane called a tonoplast. vacuole contains cell sap which is made
up of water, enzymes, minerals and waste products. vacuoles keep cells turgid - stops
, plants from wilting. also involved in the breakdown and isolation of unwanted chemicals
in the cell. tonoplast controls what enters and leaves vacuole
\disadvantage of making ropes from plant fibres - ANS - they are not as strong as ropes
made of plastic
\Double blind study deisgn - ANS - neither the doctors nor the patients know who has
been given the new drug or the placebo/old drug. this reduces bias in results as the
attitudes of the patients and doctors can't affect the results
\Endemism - ANS - when a species is unique to a single place
\Function of phloem tissue - ANS - transport organic solutes from where they are made in
the plant to where they are needed . this is translocation
\Function of schlerenchyma fibres - ANS - provide support
\Function of xylem vessels - ANS - transports water and mineral ions up the plant and
provides support
\gene pool - ANS - complete set of alleles in a species
\Genetic diversity - ANS - the variation of alleles in the gene pool of a species
\Genetically distinct - ANS - the individuals from the different populations will have
changed so much that they won't be able to successfully breed with each other to
produce fertile offspring
\Geographical isolation - ANS - when a physical barrier divides a population of a species
\Heterozygote - ANS - have two different alleles at a particular locus
\How are seeds selected for storage - ANS - from different plants to provide genetic
variation. x rayed to check for viability
\How are the xylem vessels, phloem tissue and sclerenchyma fibres arranged in plant
stems - ANS - the xylem vessels and phloem tissue group together to form vascular
bundles. the sclerenchyma fibres are associated with the vascular bundles.
\How can looking at genotype help to measure genetic diversity of a species - ANS -
analyse the sequence of base pairs in DNA samples of organisms. the order of bases in
different alleles is slightly different. by sequencing the DNA of individuals of the same
species, you can look at similarities and dfferences in the alleles. The larger the number
of dif alleles the greater the genetic diversity
\How can looking at phenotype help to measure genetic diversity of a species - ANS -
different phenotypes are coded for by different alleles, so the larger the number of
different phenotypes, the greater the diversity of alleles so the greater the genetic
diversity
\How can using plant fibres contribute to sustainability - ANS - less fossil fuel is used up
and crops can be regrown to maintain the supply for future generations. products are
biodegradable. plants are easier to grow and process than extracting and processing oil
so they are cheaper and easier to do in developing countries, as less technology and
expertise is needed
\How can using starch contribute to sustainability - ANS - making plastics (bioplastics)
and vehicle fuel (bioethanol) from starch is more sustainable as less fossil fuels are used
up crops can be regrown.
\How can zoos and seedbanks help to educate people about conserving biodiversity -
ANS - helps to raise public awareness and interest. as people get close to the organisms
