Biology

The following organelles are involved in processing amino acids into glycoprotein:
1. Golgi apparatus
2. Ribsomes
3. RER
Which sequence is correct for this process?

Antibiotics are becoming less effective due to:

Which one of the following would be different in a pair of non­-identical twins?

In a set of genetic crosses the offspring produced showed the same phenotype ratio of 9:3:3:1. Which of the following statements could be true?
1. two genes each with two alleles were studied
2. all parents were heterozygous
3. some offspring had a phenotype different to the parents
4. some offspring had a phenotype the same as the parents

Haemophilia is caused by a recessive allele carried only on the X chromosome. A carrier female and a non haemophiliac male decide to have a child.
Which of the following four statements are correct?
1 they have a 25% chance of producing a haemophiliac son

2 they have a 25% chance of producing a haemophiliac daughter

3 they have a 25% chance of producing a carrier son

4 they have a 25% chance of producing a carrier daughter

A sample of DNA contains 32 % guanine. Which answer shows the percentage of thymine in the same sample?

The diagram below represents the fluid mosaic model of the cell (surface) membrane.

Only two of the labelled molecules have both hydrophobic and hydrophilic areas. Which two molecules are they?

Which one of the following molecules is made in both photosynthesis and respiration?

Which property of water is most important when heat is lost from human skin?

A section of one strand of DNA has a base sequence of:ACG­GCT­GGT­TCC. Which of the following are correct?
1. The other DNA strand would include a CGA triplet.
2. If adenine always binds with 2 H bonds to its complementary base and guanine with 3 H bonds, then each of these triplets will have a total of 8 H bonds.
3. The mRNA sequence transcribed from this DNA sequence would contain 3 uracil bases

Which of the features below may be present in both prokaryotic cells and eukaryotic animal cells?
1 glycogen
2 a cell wall
3 DNA in loops
4 cytoplasm containing rib

The increase in the frequency of one phenotype in a wild population of fish could be due to:
1. an advantageous mutation
2. increased reproductive success of individuals with that phenotype
3. a change in the environment

Which of the following are increased when the level of adrenaline rises in a human?
1. heart rate
2. breathing rate
3. impulse rate in a sensory neurone

Which of the components of DNA listed below are found on the outside of a DNA double helix?
1. Pentose sugar
2. Phosphate
3. Purine bases
4. Pyrimidine bases

Which one of the following labels, i to v, represents a nucleotide?

If a glucose molecule became incorporated as a non­terminal component of starch, which two regions, labelled i to v, would be involved in forming glycosidic bonds?

Which of the following organisms are subject to natural selection?
1. prokaryotes that reproduce asexually
2. single-celled eukaryotes that reproduce sexually
3. organisms living in a changing environment
4. organisms living in a stable environment

The diagram below shows a phospholipid:

When this molecule is broken into a phosphate, glycerol and two fatty acids, the number of water molecules released is: