Biology Random Retrieval Y12

What technique is required when culturing bacteria?

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

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

How many chromosomes do most human cells contain?

When will the valves close?

On the graph, which letter shows where it is hardest for oxygen to associate?

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

What does Pulmonary Ventilation Rate (PVR) mean?

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

Name the contents found in C.

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.

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

Which part is hydrophobic?

In a garlic root tip squash, a student observed 124 cells, of which 19 has visible chromosomes. What was the mitotic index for that tissue?

True or false: Generally prokaryotic cells are larger than eukaryotic cells

Which of these structures is completely absent in eukaryotic cells?

Methanol is toxic. It binds to the enzyme alcohol dehydrogenase . Ethanol is similar in structure to methanol. One treatment for Methanol poisoning is to drink a lot of ethanol. What type of inhibitor is methanol?

The structure of a protein relates to its function. What is the best description of a channel protein from the following?

Fats that contain unsaturated fatty acids (compared to saturated) are more likely to have:

It forms strong, straight fibres called what ?

What word best describes this molecule?

Name the enzyme involved in the breakdown of ATP

Which bond is broken when ATP is used?

Which process requires the use of ATP?

In this experiment bacteria were grown in a growth medium containing N¹⁵. What isN¹⁵?

The diagram shows a template strand of DNA. Which of the following is the order the first 5 new bases will be added (first in the sequence, would be first to be added)?

In the diagram, what name is given to strand A?

Which enzyme works along the template DNA strand, joining new monomers together?

Name the type of bond that forms when two DNA monomers attach.

Name the pentose sugar found in DNA.

How do competitive inhibitors bring about a decrease in rate?

Will line A ever plateau if the substrate is unlimited?

Which points on the above graph show when the enzyme is denatured?

Enzymes have a very specific shape. What type of bonds hold it in that shape?

What is the name of the biochemical test for proteins?

On the above diagram, what does structure '3' represent?

It is highly branched, what type of glycosidic bond form the base of the branches?

What type of bond forms between the monomers in starch?

Which molecule is NOT glucose ?

Which elements are found in carbohydrates?

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

Type your answer.

Name the contents found in C.

On the diagram above, which structure is a phagosome?

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

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

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

True or False: Facilitated diffusion can use ATP

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

Which molecules are found in A?

Name structure E.

Name molecule J (Spell it correctly)

Name the area where the sister chromosomes together, and attach to the spindle fibres here. (Spell it correctly)

What happens in S phase?

What happens in G1 phase?

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

What does SEM stand for?

True or False : plasmids are passed on by binary fission only.

How are the circular chromosomes separated in prokaryotic reproduction?

What is structure F called?

What is the tap and water reservoir above it for?

What has happened at position A?

Name the structures labelled B

Capillaries are made only out of one layer of cells called endothelium. Why is this?

What is it called, when Carbon Dioxide causes the dissociation curve to shift?

Haemoglobin is a quaternary protein, how many polypeptide chains make up a single molecule of haemoglobin?

Why do some xerophytes have hairs over the stomatal pits?

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 letter represents the part that can control water loss?

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

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

What effect does emphysema have on the alveoli?

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

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

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

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

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?

What type of selection is shown on this graph?

Around 10,000 years ago, humans developed the ability to make lactase in adulthood, and so were able to digest diary products.

Why do most mutations cause a decrease in reproductive success?

How do new alleles occur in a population?

Why do the modern day population of Tristan De Cunha has a much higher than average incidence of the genetic disorder Retinitis Pigmentosa?

Tristan De Cunha is an island populated by a small number of Britons in the early 1800's. What is this an example of ?

After a genetic bottleneck, what is true about the alleles of the survivors?

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 does recombination increase variation?

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

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

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

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

Where does translation take place?

In eukaryotes, the pre-mRNA is modified by removing what?

What molecule is made in eukaryotic transcription?

What is transcription?

What does the 'm' stand for in mRNA?

True or False : The same three bases of DNA (or RNA) code for the same amino acid in every organism ever discovered.

True or False : The sex chromosomes ( X and Y) are not an homologous pair?