A1
The first .......... originated in water.
cells
Water is the ............. allowing it to dissolve and transport molecules around a body.
"universal solvent"
Water is a ........... in condensation and hydrolysis reactions.
metabolite
Water is a temperature buffer in bodies and .............
ecosystems
Water maintains ........... structures (such as phospholipid bilayer, proteins and DNA).
biological
State the two primary functions of nucleic acids.
1. Pass genetic information between generations.
2. Code for protein production.
List the three components of a nucleotide.
A nucleotide is the monomer subunit of the nucleic acids. A nucleotide has three component parts:
1. a nitrogenous base
2. A 5-carbon "pentose: sugar (ribose or deoxyribose)
3. A phosphate group
State the names of the nitrogenous bases found in DNA and RNA.
Cytosine (DNA and RNA)
Thymine (DNA only)
Guanine (DNA and RNA)
Adenine (DNA and RNA)
Uracil (RNA only)
Compare and contrast the functions of DNA and RNA.
DNA:
Passes heredity information between generations of cells
Codes for making RNA during transcription
RNA:
Codes for making proteins during translation
Compare and contrast the structures of purines and pyrimidines.
Both purines and pyrimidines are nitrogenous bases of DNA and RNA.
Pyrimidine: single ring nitrogenous bases
Cytosine
Thymine
Uracil
Purine: double ring nitrogenous bases
Guanine
Adenine
Which features can be found both within the plant cell and in a photosynthetic bacterium?
ribosomes
State two structural similarities between mitochondria and chloroplasts.
a. (a loop of) DNA
b. 70S ribosomes
c. double membrane
What is a difference between eukaryotic and prokaryotic cells?
Compartmentalization is found only in eukaryotes.
Explain how cladistics can be used to investigate evolutionary relationships.
a. (cladistics) shows evolutionary relationships through a common ancestor ✔
b. cladistics uses DNA/protein/derived/shared anatomical characteristics/traits ✔
c. time of divergence is related to the number of differences in DNA (base sequence) / protein (sequence of amino acids) ✔
d. homologous (versus analogous) traits are used to place an organism in a clade ✔
e. more shared characteristics mean a more recent common ancestor ✔
Outline the use of analogous and homologous traits in natural classification.
Analogous
a. different evolutionary origin/do not share (recent) common ancestor (despite similarities of function) ✔
b. arise by convergent evolution ✔
c. classification based on analogous traits brings together dissimilar species/is artificial ✔
Homologous
d. similar (internal) structures/pentadactyl limb/other example of homologous structures due to common ancestry ✔
e. different uses/functions ✔
f. arise by adaptive radiation/divergent evolution ✔
g. (natural) classification is based on homologous traits (not analogous) ✔
h. classification based on homologous traits has predictive values/matches evolutionary history ✔
Compare and contrast the structure of a typical prokaryotic cell with that of a mitochondrion.
a. prokaryote has cell wall but mitochondrion does not
b. mitochondrion has double membrane whereas prokaryote has single membrane
c. 70S ribosomes in both
d. DNA in both / loop of DNA in both / naked DNA in both
Explain how genetic variation between the individuals in a species can be generated.
a. mutation (in genes/DNA generates variation)
b. base substitution / change to base sequence of gene / makes single nucleotide polymorphisms /SNPs ✔
c. new alleles formed / different alleles of gene / multiple alleles ✔
d. radiation/mutagenic chemicals/mutagens cause/increase the chance of mutation ✔
e. meiosis (generates variation) ✔
Explain how natural selection can lead to speciation.
a. variation is required for natural selection/evolution/variation in species/populations ✔
b. mutation/meiosis/sexual reproduction is a source of variation ✔
c. competition/more offspring than the environment can support ✔
d. adaptations make individuals suited to their environment/way of life ✔
e. survival of better adapted «individuals)/survival of fittest/converse ✔
f. inheritance of traits/passing on genes of better adapted «individuals»
Outline one consequence of marine plastic pollution.
a. organisms may get tangled in plastic debris
b. animals accidentally eat plastic mistaking it for food/feed plastic pieces to offspring
c. (floating) plastic debris can block sunlight preventing photosynthesis
Outline reasons for controlling invasive plants.
a. «biotic» competition with native plants
OR
disrupt the food chain/ecosystem ✔
b. competition for abiotic factors ✔
Accept competition for light/space/water/etc for b
c. reduce competitive exclusion / avoid overlapping niches ✔
d. can cause changes to soil ✔
Describe capillary action in plant tissue.
Capillary action helps bring water from the roots all the way up to the branches and leaves. Adhesion of water to the xylem walls will cause an upward force on the water.
State two features that are found only in mammals.
a. hair/fur
b. mammary glands/breasts/(secretion of) milk/lactation
c. sweat glands
d. lungs with alveoli
e. placenta (in most mammals)
f. fetus develops in uterus/gives birth to live young
A broad bean is the seed of a species, Vicia faba, in the Fabaceae, a family of flowering plants. This family contains many species that are used as sources of food.
Vicia
What feature of eukaryotic chromosomes distinguishes them from the chromosomes of prokaryotes?
Histone proteins
Which genotype would be normally found in a gamete?
A. Rr
B. RS
C. rStt
D. TUt
B