Download Higher Human Biology Chapter 11 Questions

Chapter 11- MONOHYBRID INHERITANCE
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What name is given to a cross between two parents who possess different forms
(alleles) of one gene?

What symbol is used to represent the first filial generation in a monohybrid cross?

If true-breeding round seeded pea plants are crossed with true-breeding wrinkled seed
pea plants, what is the phenotype of the first generation if round seed is the dominant
allele?

What symbol is used to represent the second filial generation in a monohybrid cross?
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What ratio is usually obtained in the second filial generation in a monohybrid cross?

What name is given to an allele that is able to mask the presence of another allele?

What name is given to an allele that is masked by a dominant allele?

What term is used to describe an organism’s appearance based on their genotype?

Mendel formulated a principle whereby he states that the alleles of a gene exist in pairs
but when gametes are formed, the members of each pair pass into different gametes.
Thus each gamete contains only one allele of each gene. What is this principle called?

When an individual possesses two similar alleles of a gene, its genotype is said to be
HOMOZYGOUS/HETEROZYGOUS?

When an individual possesses two different alleles of a gene, its genotype is said to be
HOMOZYGOUS/HETEROZYGOUS?

Give two reasons why fruit flies are suitable for the study of genetics?

What letter is used to represent a dominant allele?

What letter is used to represent a recessive allele?

Why is the 3:1 ratio in the F2 generation not always obtained?

The probability of a particular outcome is always the same regardless of the result that
came before. If there are three yellow marbles in a box and I white marble, there is a 1
in 4 chance that a white marble will be picked each time regardless of whether a white
one was picked before or not. Lack of understanding of this principle or an unwillingness
to believe it is given what term?

Is the ability to tongue-roll a dominant or recessive trait?

Circle the following genotypes to indicate which would be tongue-rollers: RR, rr, Rr

People who possess antigen D on their red blood cells are described as what?

People who lack antigen D on their red blood cells are described as what?

If a rhesus negative person encounters antigen D, what will they make?

If a rhesus negative recipient got blood from a rhesus positive donor what term
describes what happens to the red blood cells?

Is the allele for Antigen D dominant or recessive?

What is the name of the condition where a person is unable to make melanin, the
pigment for skin, eye and hair colour?

Is this condition for inability to make melanin controlled by a dominant or recessive
allele?

What name is given to the mucus-secreting glands disorder controlled by a recessive
allele?

What name is given to the condition, controlled by a recessive allele, where a person is
unable to breakdown the amino acid phenylalanine?

Is Huntington’s Chorea a disorder that is caused by a dominant or recessive allele?

What organ system does Huntington’s Chorea attack before leading to premature
death?

At what period in a Huntington’s sufferer’s life does the disorder become expressed in
their phenotype?

What name is given to the condition where a person makes haemoglobin S?

In what way are people who suffer sickle cell anaemia different from people who suffer
sickle cell trait?

When one allele is not completely masked by a dominant allele and is partially
expressed, what term is used to describe this?

If ‘H’ is used to represent the allele for normal haemoglobin and ‘S’ is used to represent
haemoglobin S, state the genotypes for a normal person, a sickle cell trait sufferer and a
sickle cell anaemia sufferer.

What condition are sickle cell trait sufferers resistant to?

In blood groups the ABO and rhesus D antigen systems determine which blood groups
the population falls into. In addition which other factor determines blood groups?

What name is given to the fact that the M and N alleles determining blood groups, are
both expressed in the phenotype of a heterozygote?

In the ABO blood groups, which two alleles are co-dominant to one another and which
one are these two completely dominant over?

When a characteristic is controlled by three or more different alleles we say that a gene
is said to have multiple alleles-true or false?