Mod 1
The basic unit of life is the…
Cell
A group of similar cells performing the same function is called a…
Tissue
What is a sampling technique?
A method of quantitatively estimating the population of a species in an ecosystem
Name one biotic and one abiotic factor in a terrestrial ecosystem
The variable that is changed in an experiment.
Independent
Which organelle carries out photosynthesis?
Chloroplast
What organ system is responsible for transporting oxygen and nutrients around the body?
Circulatory system
This sampling technique works well on organisms that move constantly
Capture, Mark, Recapture technique
Give an example of commensalism?
Answers will vary, one eg is remora fish and sharks – remoras hitch a ride and eat leftover food scraps; the shark isn’t affected.
The variable measured in an experiment.
Dependent
What is the main structural difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have membrane-bound organelles (e.g., nucleus), prokaryotes don’t.
Name the two types of digestion
Physical and chemical
This technique allows scientists to estimate the relative abundance and density of a population
Quadrats
Define ecological niche
Role and position a species has in its environment — how it meets its needs for food and shelter, how it survives, and how it reproduces.
It includes the species’ interactions with other organisms (competition, predation, symbiosis) and with the physical environment (habitat, resources, abiotic factors).
Why do scientists repeat experiments multiple times?
To improve reliability
Name one organelle found in plant cells but not in animal cells.
Chloroplast or cell wall
Specifically, where does gas exchange occur for humans and plants?
Alveoli and stomata
The main difference in the information gathered between a line and a belt transect is...
The belt transect can gather information about the abundance of a species in the target belt area
Differentiate between absolute and relative dating.
Absolute dating gives the actual age in years, while relative dating only tells if something is older or younger.
What is the difference between validity and reliability?
Validity = whether the experiment tests the aim; Reliability = consistency of result
In an osmosis experiment, why does water move into a cell placed in a hypotonic solution?
Because the water concentration is higher outside the cell, so water moves in to balance solute concentration.
Explain translocation and the source to sink theory
Products of photosynthesis (glucose) are produced by the sources (leaves) and are transported (by the phloem) to areas of requirement known as sinks eg roots
If a scientist used 4 transects (each of area 1m2) to sample an area of 50m2 and found 4 individuals of the target species. What is the estimated abundance of the species?
estimated number is 50 individuals
Explain how ice core drilling and the subsequent gas analysis provides data of past environmental conditions.
Ice cores trap ancient air bubbles; analysing their gases (like CO₂) reveals past temperatures and atmospheric conditions.
A student tests plant growth with three different fertilisers. What controls must be in place to make this a fair test?
Same plant species, same soil, same amount of fertiliser, equal light, water, temperature, pot size, etc.