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what are the bonds that from between amino acids called?
Peptide Bonds
Describe the role of decomposers in ecosystems (1 mark)
a. decomposers are bacteria/fungi /invertebrates;
b. break down dead organic matter / faeces;
c. release/recycle minerals/nutrients (into the environment)
Define pollination
the transfer of pollen from anther to stigma
What part of the lungs is responsible for gas exchange?
Alveoli
What are the pancake like structures in chloroplasts called?
Thylakoids
state the fuction of flagella and ribosomes in prokaryotic cells
Flagella = movement/locomotion
ribosome = protein synthesis/translation
Distinguish between the structure of the nucleotides in DNA and RNA
a. DNA contains deoxyribose and RNA contains ribose;
b. DNA contains thymine and RNA contains uracil;
By which process do potassium ions move through potassium channels in axons?
Facillitated Diffusion
What are the three parts of a nucleotide?
Five carbon sugar (ribose or deoxyribose), phosphate group, nitrogenous base (ATCG)
What two organs make up the Central Nervous System (CNS)?
Brain and spinal cord
State the laboratory method used to amplify DNA.
PCR / polymerase chain reaction
Cell membranes have a fluid mosaic structure. Outline the reason the structure is described as a mosaic
proteins/glycoproteins/glycolipids are found throughout the phospholipids;
The electron micrograph shows part of a synapse between two neurons. Deduce what type of substance the vesicles contain.
neurotransmitter/acetylcholine/another verified example of neurotransmitter;
What is the order of phases with mitosis (6 phases)?
Prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
Which two systems are responsible for communication in the body?
Nervous system and Endocrine system. Nervous system is faster, but Endocrine signals can last much longer.
Define the term autotroph
uses light/external sources (chemicals) as an energy source to make complex carbon/organic compounds (from simple/inorganic molecules);
List human actions that could threaten populations of insect pollinators such as bees. [3]
a. use of pesticides/insecticides (which may kill/harm pollinators);
b. urbanization;
c. loss of habitat/change of land use (monocultural/intensive farming practices);
d. use of herbicide or removal of "weeds" reducing food sources;
e. introduction of alien species;
Explain how analogous structures can evolve
a. evolution occurs by natural selection;
b. analogous structures come from convergent evolution;
c. analogous structures have similar functions or structures evolved from different ancestry;
d. similar conditions/environments have similar selective pressures favouring similar adaptations;
e. similar functions/functional requirements result in similar adaptations/structures;
f. e. g. torpedo shaped body in sharks and whales to facilitate swimming/ another verified example;
What is the difference between codominance and incomplete dominance?
Incomplete dominance - mixing of traits (red and white alleles make pink). Codominance - both traits expressed equally (roan cow/ AB blood type)
What are the two steps to protein synthesis and where do they occur?
Transcription: occurs in the nucleus
Translation: occurs at ribosomes (either in cytoplasm or on rough ER)
Outline the role of surfactant in the mammalian lung
a. moistens the inside wall/surface of the alveoli;
b. reduces surface tension (inside alveoli);
c. prevents (alveoli) walls/surfaces sticking together OR helps to prevent collapse of the lungs;
d. enhances (alveolar) expansion of lungs OR allows the inflation of lungs after birth;
A cell has been identified as having the following values:
- solute potential=-0.75 MPa
- pressure potential = +0.30MPa
calculate the water potential for this cell
-0.45(MPa)
What are the two major phases of photosynthesis and the three major phases of cell respiration?
Photosynthesis: Light dependent reactions, Calvin Cycle (light dependent/dark reaction)
Cellular Respiration: Glycolysis, Krebs Cycle, Electron Transport Chain
State what a biome is [2]
- groups of ecosystems with similar communities
- similar abiotic conditions
- evolution produces similarities between ecosystems in a biome
Describe how scientists can assess whether the rate of harvesting of fish is sustainable. [2]
measure rate of replacement/reproduction,
rate of harvest should be lower than the rate of replacement