Category: Biology

Why do some xerophytes have hairs over the stomatal pits?

Why do some xerophytes have their stomata in pits?

What is a xerophyte?

Why do the guard cells become 'curved' when they swell up?

How does water move into the guard cells?

Which term describes that guard cells when the plant has plenty of water available?

Why are there large gaps between the mesophyll cells ?

How is a concentration gradient maintained inside the leaf?

Which number represents a layer which is 2 or 3 times thicker in desert plants?

Which number represents cells that can control water loss?

Which number represents a stoma?

Which number represents the layer where gaseous exchange happens in plants?

What maintains the concentration gradients for gaseous exchange in the tracheoles?

Oxygen diffuses out of the tracheoles directly into what?

Which letter represents the part that can control water loss?

Which letter is the tracheae?

Which letter is the spiracles?

The diagram shows an insect respiratory system. Which letter represents the tracheoles?

Why does the blood flow in an opposite direction the the water?

The blood and water flow in opposite directions, what is this called?

What is the function of the lamellae?

Using the diagram, which part is a lamella?

Using the diagram, which part is a gill filament?

Many species of fish have developed a technique to allow a constant flow of oxygenated water over the gills, even when stationary. This is called Buccal Pumping, how does it work?

The Great White Shark and Black-tipped Reef Shark are two species which must keep swimming to stay alive. Why is this?

Which letter represents the trachea?

Which two letters would be held open by C shaped cartilage rings?

Which letter represents the diaphragm?

Which term best describes breathing?

What shape is the diaphragm when it is contracted?

Which muscles are contracted when you inhale?

Which of the following is the correct sequence for inhalation?

True or False - Air moves into the lungs because the internal pressure in the lungs drops below the atmospheric pressure?

Which muscles contract when you exhale at rest?

Which muscles contract during forced expiration?

As oxygen diffuses from the alveolar air space into the blood, how many layers of cells does it pass over?

What is the correct term for the cells which make up the alveolar wall?

How is a concentration gradient maintained between the alveolar space and the blood?

What does Pulmonary Ventilation Rate (PVR) mean?

Pulmonary Ventilation Rate ( PVR) -= Tidal Volume x breathing rate. If someone take 60 breaths over 5 minutes, and takes in 230 cm³, what is their PVR?

Pulmonary Ventilation Rate ( PVR) -= Tidal Volume x breathing rate. If the breathing rate is 7, and the PVR is 1.4 dm³ min ^-1, what is the tidal volume?

If someone's PVR is 1.5dm³ min ^-1, and their tidal volume is 150 cm ³, how many breaths do they take in a minute?

Forced Expiratory Volume (FEV) is the maximum volume of air that can be breathed out in 1 second. What is the FEV for person B?

Why might the FEV be lower for person B?

Why would someone with Pulmonary Fibrosis have a reduced rate of oxygen diffusion?

Tuberculosis (TB) is caused by bacteria infecting the lungs, where amongst other effects it reduces tidal volume. What happens to the ventilation rate of sufferers?

Emphysema is caused by what?

What effect does emphysema have on the alveoli?

Sufferers of emphysema also have reduced elastin in the alveolar walls. What effect does this have on breathing?

What is 'Tidal Volume'?

The surface area in biology often refers roughly to how much skin an organism has, or how much cell membrane a cell has. Which of the following will have the biggest surface area, if they are all approximately the same length and width?

A Palisade cell is rectangular, and measures 100 µm by 40 µm. What is its surface area?

What is the volume of the same palisde cell measuring 100 µm by 40 µm?

What is the surface area to volume ratio of a palisade cell with a volume of 120,000 µm ³ and a surface area of 6500 µm²?

If we assume a spongy mesophyll cell is approximately a sphere. Using the formula 4 pi r ² , what is its surface area if its diameter is 80 µm?

What is the volume of the same roughly spherical spongy mesophyll cell with a diameter of 80 µm, using the formula Volume=4/3 pi r ³?

What is the surface area to volume ratio of a spongy mesophyll cell with the surface area of 24,000 µm ², and a volume of 110,000µm ³?

Is it important which way round the numbers go when writing a ratio?

Cresol red is an indicator which goes clear at a low pH. A plate of agar jelly with cresol red added was made, and two blocks were cut out. Block A measured 10mm x 10mm x 10mm. Block B measured 20mm x 7mm x 7mm. Are they a similar volume (within 5% difference)?

Cresol red is an indicator which goes clear at a low pH. A plate of agar jelly with cresol red added was made, and two blocks were cut out. Block A measured 10mm x 10mm x 10mm. Block B measured 20mm x 7mm x 7mm. Are the two agar blocks a similar surface area (within 5% difference)?

Cresol red is an indicator which goes clear at a low pH. A plate of agar jelly with cresol red added was made, and two blocks were cut out. Block A measured 10mm x 10mm x 10mm. Block B measured 20mm x 7mm x 7mm. Which one will decolourise quickest when placed in an acidic solution ?

Cresol red is an indicator which goes clear at a low pH. A plate of agar jelly with cresol red added was made, and two blocks were cut out. Block A measured 10mm x 10mm x 10mm. Block B measured 20mm x 7mm x 7mm. You have chosen one which will decolourise the quickest, why did you choose that block?

Why can single celled organisms exchange many substances by simple diffusion over the plasma membrane?

Multicellular organisms cannot absorb enough substances by diffusion. Why is this?

How have multicellular organisms adapted to not being able to absorb everything via diffusion over their surface?

Some animals are adapted to higher temperatures in their environment. Which of the following is an example of this ?

Some animals are adapted to a lower environmental temperature. Which of the following is an example of this?

Other than surface area to volume ratio, which is an example of a physiological adaptation, which allows an animal to live at colder temperatures?

Other than surface area to volume ratio, which is an example of a physiological adaptation, which allows an animal to live at hotter temperatures?

Which is an example of a behavioural adaptation which allows an animal to live at hotter temperatures?

Name the molecules that generate an immune response when detected by the body. Type your answer.

Which type of cell can engulf a pathogen?

During phagocytosis, the pathogen is detected by molecule A on the cell surface membrane. What are the molecules labelled A called?

On the diagram above, which structure is a phagosome?

On the diagram above, which structure is a lysosome?

Name the contents found in C.

Digested pathogen proteins can be displayed on the cell surface membrane of a phagocyte. What is this called?

Type your answer.

Which type of cell activates other immune cells in an immune response?

Which type of cell travels to the site of infection, and secretes a chemical which kills infected cells?

What happens to a B lymphocyte when it is activated?

True or False - Plasma cells are clones.

True or False - Each B cell has an antibody with a different shaped variable region on its membrane.

What is it called when the two variable regions of an antibody form a complex with two pathogens?

Type your answer.

Which is the variable region on the above diagram?

On the above diagram, where would an antigen bind?

What is the primary function of a vaccination?

NMO is a disease NMO is a disease that leads to damage to nerve cells in the spinal cord. A person with NMO produces anti-AQP4 antibody that attacks only these nerve cells. Explain why the anti-AQP4 antibody only damages these cells

A doctor vaccinated a group of patients against poliomyelitis. He gave each patient two doses of vaccine, 3 months apart. Calculate the percentage increase in the mean concentration of antibodies in blood between samples 2 and 3.

A doctor vaccinated a group of patients against poliomyelitis. He gave each patient two doses of vaccine, 3 months apart. Explain the differences between the mean concentrations of antibodies in blood samples 1 and 2 .

A doctor vaccinated a group of patients against poliomyelitis. He gave each patient two doses of vaccine, 3 months apart. Explain the differences between the mean concentrations of antibodies in blood samples 2 and 3.

What type of transport is osmosis?

Is a higher water potential...

What is the water potential of pure water?

In the above diagram of three cells, will water move from :

In the above diagram of three cells, will water move from:

Complete this sentence: Osmosis is the diffusion of water across a partially ________ membrane . Type your answer:

When investigating osmosis, why is it better to calculate the percentage change in mass, rather than just the change in mass?

When investigating osmosis, you often need to make different concentrations of solute solution. Describe how you would make up 30 ml of 0.15 mol dm ^-3,from 1 mol dm ^-3 stock solution.

A worm native to fresh water will die when placed in sea water. Why is this?

Which of the following is a similarity between diffusion an osmosis?

Which of the following is a similarity between diffusion an osmosis?

Read the above passage. Before reweighing, the potato was blotted dry. Which of the following is NOT a reason for doing this?

Look at the above graph, what is the concentration of sodium chloride inside the potato cells?

In the above experiment, why would the student be advised to take repeat readings?

In the above experiment, why would the student be advised to take repeat readings?

Which term describes a solution with a lower water potential than the cells bathed in it?

Other than glucose, which substance can be absorbed from the ileum via co-transport?

During co-transport of glucose in the ileum, active transport is needed to establish a concentration gradient of which substance?

Which protein needs to be used first in the co-transport of glucose across a membrane. For example in the ileum.

In the above diagram, there are three membrane proteins: A, B and C. Which represents where facilitated diffusion occurs?

In the above diagram, there are three membrane proteins: A, B and C. Which represents where co-transport occurs?

Would the number of carrier proteins present affect the rate of active transport across a membrane?

True or False: Facilitated diffusion can use ATP

True or false : Active transport can go down a concentration gradient, or up a concentration gradient.

True or false : Facilitated diffusion can use channel proteins or transport proteins, but active transport only uses transport proteins.

In the above experiment, two flasks contained identical masses of animal tissue, identical volume of a solution containing sodium ions, but an inhibitor of ATP production in flask F. Why did flask F plateau?

In the above experiment, two flasks contained identical masses of animal tissue, identical volume of a solution containing sodium ions, but an inhibitor of ATP production in flask F. Scientists concluded that flask G took up sodium ions by active transport. What is the evidence of this?

a) Uptake in flask G much greater than in flask F , showing use of ATP in flask G

b) Sodium ion concentration in flask G falls to zero, showing uptake against a concentration gradient

In the above experiment, two flasks contained identical masses of animal tissue, identical volume of a solution containing sodium ions, but an inhibitor of ATP production in flask F. Calculate the rate of the uptake of sodium ions in flask G, in the first 20 minutes.

True or False: In order to function, carrier proteins have to change shape.

Which type of membrane protein is not involved in facilitated diffusion?

Does a concentration gradient need to be established before facilitated diffusion can take place?

Which of the following factors when increased, will decrease the rate of diffusion?

a) The Concentration Gradient

b) The Surface Area

c) The Diffusion Pathway

Which of the following factors when increased, will increase the rate of diffusion?

a) The Concentration Gradient

b) The Surface Area

c) The Diffusion Pathway

Which part of the phospholipid bilayer prevents sodium ions leaving via simple diffusion?

Why can't glucose diffuse directly through the phospholipids?

Which of the following molecules can diffuse directly through the phospholipid bilayer?

a) Oxygen
b) Carbon Dioxide
c) Lipids

Which part is hydrophobic?

Name molecule J (Spell it correctly)

Which part is hydrophilic?

What name describes the double layered structure of a membrane? (Spell it correctly)

Name the part of molecule J, which makes up part B.

Which molecule makes up part D?

Name structure E.

What substance will structure C be made out of?

Name structure G.

Name molecule I.

Which molecules are found in A?

What type of molecules are most likely to pass through C?

Give an example of a molecule which would pass through F

What effect does having more of molecule 'I' have on the membrane?

Beetroot is a purple vegetable, the cells of which contain a pigment called Betalain. 4 tubes are set up with water and beetroot incubated at different temperatures: 20, 40, 60 and 80 ⁰C. What is the dependent variable of this experiment?

Beetroot is a purple vegetable, the cells of which contain a pigment called Betalain. 4 tubes are set up with water and beetroot incubated at different temperatures: 20, 40, 60 and 80 ⁰C. which tube would you predict shows beetroot incubated at 20 ⁰C?

What piece of equipment can you use to measure the colour change? (spell it correctly)

Why can more pigment leak out across the plasma membrane at a higher temperature (80⁰C) ?

In this version of required practical 4, 1cm beetroot cores are soaked in different concentrations of ethanol - 0%, 10%, 20%and 30%. Which graph represents the expected results ?

Which is the best explanation for the effect of ethanol on membrane permeability?

What word describes cells which contain pairs of chromosomes?

What word do we use to describe the pairs of chromosomes?

What word describes cells which contain single chromosomes?

On this diagram, what does A represent?

On this diagram, what does B represent?

On this diagram, what does C represent?

On this diagram, what does D represent?

Before meiosis starts, the primary spermatocyte or oocyte replicates its chromosomes and organelles. What is this phase called?

There are now two identical copies of each chromosome, held together by the centromere. Which term best describes these identical copies?

How many chromatids are present in a human cell at the start of meiosis?

As there are now 4 chromatids in each homologous pair, they are sometimes called what?

Which number represents prophase 1 of meiosis?

Which number represents metaphase 1 of meiosis?

How does metaphase 1, differ from metaphase 2 in meiosis?

Is Anaphase 2 more similar to Anaphase 1, or Anaphase in mitosis?

What is the order of events from the diagram for Meiosis division 2?

How is variation introduced during prophase 1?

During recombination ( crossing over), genetic material can be swapped between which two structures?

How does recombination increase variation?

During Metaphase 1, the homologous pairs can line up with either the paternal chromosome above, or the maternal chromosome above. What is this phenomenon called?

How many different combinations of maternal / paternal chromosomes are there if there are 23 pairs?

What is the main cause of variation between siblings?

A sheep cheek cell which is not dividing has 54 chromosomes, how many chromatids will be present during Meiotic Prophase 1 in the testes?

The goat cardiomyocyte has 30 pairs of chromosomes. How many chromatids will be present in each cell formed at the end of meiosis Telophase 2?

What term describes the ability to see two separate points, as two separate points. Rather than one large point on an image ? (You need to spell it correctly!)

Which of the following organelles are visible with a light microscope?

a) Nucleus
b) Lysosomes
c) Chloroplasts

Which of the following are NOT visible with a light microscope?

a) Plant Permanent Vacuole
b) Rough Endoplasmic Reticulum
c) Golgi Body

What does TEM stand For?

What does SEM stand for?

Which type of electron microscope produces a 2D image?

Which type of electron microscope show the density of the specimen as a dark patch?

Which type of electron microscope can only be used on non-living samples?

Which type of electron microscope can be used on a thick specimen?

Which type of electron microscope produced this image?

Which type of electron microscope produced this image?

To look at a fresh sample under a light microscope, you'll need to prepare a temporary mount. What is NOT used to stick the specimen to the microscope slide?

To look at a sample under a microscope, you need to prepare a temporary mount. Why does the specimen have to be thin?

Which organelle will be found in pellet A?

Which organelle will be found in pellet B?

Which organelle will be found in pellet B?

Which organelle will be found in supernatant C?

The process shown in the diagram is 'Cell ___________' (spell it correctly)

Why must the solution used to homogenise be cold?

As well as being cold, what must the solution also be?