Biology Year 13 Random Retrieval

Acetylation is the addition of a C2H3O group which contains a double bonded oxygen. Where does acetylation occur?

Which molecule is created during transcription?

If hypermethylation happens to a proto-oncogene, what effect will this have on the rate of mitosis?

Fill in the missing word : Causes of Mutations A mutation is any change to the order of __12___ in the genetic code. These occur naturally as the enzyme _____13_____ replicates the DNA and makes mistakes. The incidence can also be produced due to exposure to certain agents called mutagenic agents. These can be chemicals such as nitrous acid, which converts cytosine to uracil.

Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene. UV radiation is also a mutagenic agent.

It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Name the enzyme that breaks the hydrogen bonds between complimentary bases during DNA replication.

Name the type of bond that holds the complementary base pairs together.

What is it called when succession is stopped artificially?

A student is using a quadrat to estimate percentage cover of clover on the school field. What is the most accurate way to do this?

Which method would you use to see if there is a correlation between profile height and percentage cover of marsh grass?

How many samples should you take to get reliable data?

What type of variation is show in the graph?

Which type of selection is shown by Darwins finches, where small and large beaks were both at an advantage due to different food sources?

Which statistical test would we use to see if the observed phenotypes are different from the expected phenotypes?

The actual ratio of phenotypes after several matings between the above two hamsters was more similar to 6:1:1:6. How are the alleles linked?

One form of muscle disease is caused by a mutated allele of a gene. This leads to production of myosin molecules that are unable to bind to other myosin molecules. If myosin molecules are unable to bind to other myosin molecules, this prevents muscle contraction. Suggest why.

What is the structural adaptation which give cones high visual acuity compared to rod cells?

What affect does IAA have on shoot tips?

Denitrifying bacteria use nitrates in the soil to carry out respiration and produce nitrogen gas. Are the vast majority aerobic or anaerobic?

The above table shows the volume and density of a fresh wood sample, then the volume and density of the same sample after it was dried. Calculate the percentage of water in the sample (water weighs 1g / ml)

In this investigation, are the yeast respiring anaerobically or aerobically ?