Describe the movement of energy and nutrients in an ecosystem.

Explain how sexual reproduction can eventually lead to evolution in offspring.

Using simple external recognition features, distinguish between the plant phyla bryophyta and angiospermophyta.

ecosystem is a community and its abiotic environment;
solar energy collected by autotrophs/plants (via photosynthesis);
moves through trophic levels via food;
only 5 to 20% transferred from one trophic level to next / never 100% efficient;
lost as metabolic heat/organic waste;
energy flow can be illustrated by pyramid shape;
organisms absorb nutrients from food/environment;
nutrients occur as complex organic matter in living organisms;
after death, saprotrophic bacteria and fungi (decomposers) breakdown complex organic matter;
breakdown products are simpler substances;
absorbed into plants for resynthesis into complex organic matter/recycled;

offspring vary in traits;
variation results from sexual reproduction;
independent assortment of alleles (during meiosis of spermatogenesis/ oogenesis) contributes to variation;
meiosis is the cellular process that produces gametes;
crossing over (during meiosis) increases variation;
fertilization (combination of different genomes) contributes to variation;
more offspring may be produced than the environment can hold;
struggle for existence can occur;
offspring whose traits best adapt them to environment will survive/survival of fittest;
change in environment will lead to survivors with new/different traits;
correct use of term natural selection/selective pressure;
variation is heritable / over time more offspring born with new trait;
change in gene pool;
when entire population (of a species) exhibits new trait, evolution has occurred;

Candidates demonstrated a good understanding of the movement of both energy and nutrients in ecosystems. The best responses were illustrated with energy pyramids or nutrient diagrams.  

The role of sexual reproduction in evolution was well answered in general. The best answered laid out a step-wise sequence of events that explained how sexual reproduction leads to evolution with real life examples such as Galapagos Island Finches.

Few candidates could recall any detail of the characteristics of the plant phyla bryophyta and angiospermophyta. Many did use a table to distinguish between the two phyla, which was an appropriate way to approach the answer, however the lack of detail let most candidates down.