Plant Reproduction
What are the male and female reproductive organs of a flower called?
Male = stamen, Female = carpel (or pistil)
What is seed dispersal?
The spreading of seeds away from the parent plant.
What is a species?
A group of organisms that can reproduce together and produce fertile offspring.
What is an adaptation?
A characteristic that helps an organism survive and reproduce.
In energy transfers, what does the law of conservation of energy state?
Energy cannot be created or destroyed, only transferred between stores
What is the difference between pollination and fertilisation?
Pollination is the transfer of pollen to a stigma; fertilisation is the fusion of the male nucleus and egg cell.
Give two reasons why plants benefit from dispersing their seeds.
Reduced competition for light, water and minerals; reduced risk from diseases and predators.
What are the three domains of life?
Archaea, Bacteria and Eukarya.
What is variation?
Differences between individuals of the same species.
Why are gases much easier to compress than liquids?
Gas particles are much further apart with empty space between them.
Why is self-pollination usually disadvantageous for a species?
It reduces genetic variation, making populations less able to survive environmental changes.
Name four methods of seed dispersal.
Wind, water, animals, and explosive dispersal.
What is the purpose of a classification key?
To identify organisms using a series of questions based on their characteristics.
Why is variation important in natural selection?
Some variations help organisms survive better than others.
A student says, "All offspring inherit exactly half of their characteristics from each parent." Explain why this statement is not always true.
Offspring inherit genes from both parents, but dominant and recessive alleles affect which characteristics are expressed.
Explain how the structures of insect-pollinated flowers differ from wind-pollinated flowers.
Insect-pollinated flowers have large colourful petals, nectar and sticky pollen; wind-pollinated flowers have small petals, exposed anthers and light pollen.
Why are dandelion seeds adapted for wind dispersal?
They have a large surface area and low mass, allowing them to be carried long distances by the wind.
What is the genus and what is the species of a black rat?
Genus = Rattus; Species = rattus.
Explain how dark peppered moths became more common during the Industrial Revolution
Dark moths were better camouflaged on soot-covered trees, so birds ate fewer of them. More survived and reproduced, passing on the dark-colour allele.
A house has loft insulation, cavity wall insulation and double glazing. What do all three features have in common?
They reduce unwanted energy transfers, increasing efficiency and reducing heating costs.
A flower has bright petals and sticky pollen but produces very little nectar. Explain why it is still likely to be insect-pollinated and identify which feature provides the strongest evidence.
It is likely insect-pollinated because sticky pollen is adapted to attach to insects. The sticky pollen is stronger evidence than nectar because it directly affects pollen transfer.
Two equally sized plants grow in the same habitat. One produces thousands of light seeds, while the other produces a few large fruits. Explain the advantages and disadvantages of each strategy.
Many small seeds increase the chance of reaching new areas but most die. Fewer large seeds have more food reserves and a greater chance of survival but fewer offspring are produced.
A scientist discovers an organism with a nucleus, chloroplasts and a cell wall. Explain why this information alone is not enough to identify its species.
Many species share these characteristics. Classification requires more detailed structural, genetic or reproductive information because many organisms belong to the same kingdom.
A disease kills 90% of a rabbit population. A few rabbits survive because they carry a gene that gives resistance. Predict how the population may change over several generations.
Resistant rabbits survive and reproduce more successfully. The resistance gene becomes more common in the population through natural selection.
Challenge Question: A plant species produces seeds that are dispersed by birds. Over many generations, fewer birds visit the area. Predict how this could affect the evolution of the plant species.
+50 points
Plants with mutations that allow seeds to be dispersed by other methods (such as wind, water or mammals) would be more likely to reproduce successfully. Over time, natural selection could favour these adaptations, changing the characteristics of the population.