Q: What are male gametes called in
mammals?
A: Sperm
Q: Where are sperm produced?
A: In the testes.
Q: What is fertilisation?
A: The fusion of the nuclei of the male
and female gametes.
Q: What is formed when the nuclei of
the male and female gametes fuse
together?
A: A zygote
Q: What are female gametes called in
mammals?
Q: What controls an organism’s
characteristics?
A: Eggs
A: Genetic information on chromosomes.
Q: Where are eggs produced?
Q: Describe the structure of a
chromosome?
A: In the ovaries.
A: Chromosomes are composed of a long
chain of DNA bases.
Q: What are male gametes in flowers
called?
Q: What are the letters that represent
the DNA bases?
A: Pollen
A: C, G, A and T
Q: Where is pollen produced?
Q: Why is the order of the DNA bases
important in protein synthesis?
A: The anthers
A: The DNA bases code for the sequence
of amino acids that make up the protein.
Q: What are female gametes in flowers
called?
Q: Why is the sequence of amino acids
important?
A: Ovules
A: This dictates the structure and
functions of a protein
Q: Where are ovules produced?
Q: Name three proteins present in human
cells?
A: In the ovary.
A: Haemoglobin, enzymes and hormones.
Q: How many sets of chromosomes are
found in body cells?
A: 2 matching sets
Q: What does the random way in which
gametes meet during fertilisation result
in?
A: Increased variation in offspring
Q: How many sets of chromosomes are
found in gametes?
Q: Which sex chromosomes can be
inherited from a human mother?
A: 1 set
A: X
Q: During which process are the
chromosomes reduced to one set?
Q: Which sex chromosomes can be
inherited from a human father?
A: Meiosis (gamete formation)
A: X and Y
Q: What happens to the chromosomes
during meiosis?
Q: Name the sex chromosomes found in a
human female body cell.
A: Matching pairs line up and then
separate.
A: XX
Q: How is variation in offspring
introduced during meiosis?
Q: Name the sex chromosomes found in a
human male body cell.
A: Random Assortment of chromosomes
A: XY
Q: In humans, how many chromosomes
are found in one set?
Q: Do all species have 46 chromosomes in
their body cells?
A: 23 chromosomes
A: No, different species have different
numbers of chromosomes.
Q: In humans how many chromosomes are
found in body cells?
Q: What are genes?
A: 46 chromosomes
Q: During which process are the
chromosomes restored to 2 sets?
A: Fertilisation
A: Parts of a chromosome that control
inherited characteristics.
Q: What are the different forms of a
gene called?
A: Alleles
Q: How many alleles of a gene are found
in each gamete?
Q: Name the type of cross that examines
one single characteristic.
A: One
A: Monohybrid cross
Q: Give the meaning of genotype.
Q: What F1 phenotypic ratio results from
two true-breeding parents?
A: The complete set of genes possessed
by an organism.
Q: Give the meaning of phenotype.
A: The observable characteristics
(appearance) of an organism.
Q: An organism with two identical alleles
in its genotype is said to be what?
A: Homozygous
A: All dominant
Q: What F1 phenotypic ratio results from
two heterozygous parents?
A: 3 dominant: 1 recessive
Q: What F1 phenotypic ratio results from
one heterozygous parent and one
homozygous recessive parent?
A: 1 dominant: 1 recessive
Q: An organism with two different alleles
in its genotype is said to be what?
Q: Why are there differences in the
expected and observed ratios?
A: Heterozygous
A: Fertilisation is a random process
Q: What alleles would a true breeding
organism have in its genotype?
Q: What is the name given to the alleles
of a gene that are neither dominant nor
recessive and both are displayed in the
phenotype?
A: Two identical alleles.
A: Co-dominant
Q: What is the name for an allele that is
always shown in the phenotype?
Q: What is polygenic inheritance?
A: Dominant
A: This is when a characteristic is
controlled by the interaction of the
alleles of several genes.
Q: This type of allele is always masked by
a dominant allele.
Q: What does polygenic inheritance
result in?
A: Recessive
A: A range of phenotypes e.g. skin colour
Q: What affects the final appearance of
an organism?
Q: What is selective breeding?
A: Genotype and the effects of the
environmental.
A: The breeding of plants and animals
which show desirable characteristics.
Q: What term describes the cause of
organisms with identical genotypes having
different phenotypes?
Q: Why does it take a relatively long
period of time to improve offspring with
selective breeding?
A: Environmental impact
A: The results are not guaranteed so
several generations may be required.
Q: Why are any changes in phenotype
caused by environmental effects not
evolutionary significant?
Q: What is the purpose of genetic
engineering?
A: They are not passed from one
generation to the next.
A: To produce a desired product.
Q: What is natural selection?
Q: Describe what happens during the
first step in genetic engineering?
A: The process by which organisms that
are better adapted to their environment,
survive and breed, while those less well
adapted fail to do so.
A: Identify the required human gene and
a suitable bacterial cell.
Q: Why is the light form of the peppered
moth better adapted to survive in rural
areas?
Q: Describe what happens during the
second step in genetic engineering?
A: They gain camouflage on light coloured
bark so are more likely to survive and
pass their genes on to future
generations.
A: Isolate the required human gene and
the plasmid from the bacterial cell.
Q: Why is the dark form of the peppered
moth better adapted to survive in
polluted areas?
Q: Describe what happens during the
third step in genetic engineering?
A: They gain camouflage on dark coloured
bark so are more likely to survive and
pass their genes on to future
generations.
A: Insert the required human gene into
the plasmid.
Q: Describe what happens during the
fourth step in genetic engineering?
A: Insert the plasmid containing the
human gene into the bacterial cell.
Q: Describe what happens during the
fifth step in genetic engineering?
A: Grow the bacterial cell so that they
produce the required product.
Q: Describe what happens during the
sixth step in genetic engineering?
A: Purify the required product.
Q: Name two medicines produced by
genetic engineering?
A: Insulin and Human Growth Hormone.
Q: Name two advantages of genetic
engineering?
A: Increased range of products and
increased rate of production.
Q: Name two disadvantages of genetic
engineering?
A: The possible release of genetically
engineered bacteria into the environment
and the cost of development.