Cells
What name is given to cells that lack a nucleus?
Prokaryotes
What type of bonding occurs between water molecules to give it cohesive properties?
Hydrogen bonding
What is the name given to non-living factors in an ecosystem?
Abiotic
Which type of cells does the HIV virus affect?
T-helper cells
How many IB biology papers will you sit?
2
Which type of stem cell has the potential to divide into any cell type including placental cells?
Totipotent stem cells
Name 3 types of movement across cell membranes.
- Simple diffusion
- Facilitated diffusion
- Active transport
What name is given to an organism that feeds on dead organic matter?
A detritivore.
What is the role of LH in the menstrual cycle?
The LH surge triggers ovulation
How many pets do I have?
3
What stage of the cell cycle does DNA replication occur?
S phase of interphase (synthesis phase)
Outline 3 key differences between RNA and DNA
- RNA is single stranded whereas DNA is double stranded
- RNA contains the bases A,U,C,G whereas DNA contains the bases A,T,C,G.
- RNA contains the sugar ribose whereas DNA contains deoxyribose.
Name three greenhouse gases
- Carbon dioxide (CO₂)
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Water vapor (H₂O)
Name 3 negative feedback mechanisms to thermoregulate when you get too cold.
- Vasoconstriction
- Shivering
- Piloerection (hairs standing on end)
- Behavioural
- Increased metabolism
What is the longest river in the world?
The Nile
At what stage of meiosis do the bivalents form?
Prophase 1.
What would happen to both a plant cell and an animal cell placed in a hypotonic solution?
- Plant cell would experience turgor pressure and swell, the animal cell would lyse.
Give an example of a symbiotic relationship
E.g.
A lichen, which is a mutualistic relationship between fungi and algae (or cyanobacteria)
Outline the process of inspiration (including the muscles involved and relative pressure).
Diaphragm contracts and moves downward.
External intercostals contract, raising the rib cage.
The volume of the thoracic cavity increases, and the pressure inside the lungs decreases, causing air to flow in.
This actor portrayed Iron Man, also known as Tony Stark, in the Marvel Cinematic Universe
Robert Downey Jr.
Name the three postulates of the cell theory:
- All living things are made of cells.
- Cells are the basic unit of structure and function in organisms.
- All cells come from pre-existing cells.
Outline the stages in PCR.
- Denaturation (High temp breaks H-bonds separating the DNA into two single strands)
- Annealing (lowered temp allows primers to bind/ anneal to target complementary sequences)
- Extension/ elongation (Taq polymerase adds nucleotides to the 3' end of each primer)
Name an example of a keystone species and how it affected an ecosystem
E.g.
Grey wolves in Yellowstone national park
The reintroduction of grey wolves led to a decrease in the elk population, which allowed vegetation, such as willow and aspen, to recover. This, in turn, benefited other species like beavers, birds, and fish, and restored balance to the ecosystem.
Summarise the (4) phases of an action potential in a motor neuron.
Depolarization: Sodium influx (+)
Repolarization: Potassium efflux (-)
Hyperpolarization: Overshoot of negativity
Restoration of resting potential: Sodium potassium exchange pump
I have keys but open no locks. I have space but no room. You can enter, but you can't go inside. What am I?
A keyboard