1 markExtended Tier Only
What does the term haploid mean?
A nucleus containing two sets of chromosomes.
A nucleus containing a single set of chromosomes.
A person with only one X chromosome.
A person with XXY chromosomes.
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1 markExtended Tier Only
When a somatic (body) cell undergoes cell division, two daughter cells are produced with the same chromosome number as the parent cell.
Which type of division has taken place?
Meiosis producing genetically different cells.
Mitosis producing genetically identical cells
Meiosis producing genetically identical cells.
Mitosis producing genetically different cells.
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1 markWhich shows the correct size order of structures, starting with the smallest?
gene → DNA strand → chromosomes → nucleus
DNA strand → chromosomes → gene → nucleus
chromosomes → gene → DNA strand → nucleus
nucleus → chromosomes → DNA strand → gene
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1 markMales and females have a unique set of chromosomes.
What is the correct combination of male and female chromosomes?
Male XY
Female YY
Male YX
Female XY
Male XY
Female XX
Male XX
Female XY
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1 markA tall pea plant is crossed with a short pea plant. The tall gene is dominant over the short gene. The tall plant is heterozygous. The short plant is homozygous recessive
Which is the correct genetic diagram for this cross?
| t | t | |
| T | Tt | Tt |
| T | Tt | Tt |
| t | t | |
| T | Tt | Tt |
| t | tt | tt |
| T | t | |
| T | TT | Tt |
| t | Tt | tt |
| T | T | |
| t | Tt | Tt |
| t | Tt | Tt |
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1 markExtended Tier Only
New cells are formed by the division of existing cells.
The diagram below shows four different cells.
Which one is formed by meiosis?
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1 markAlbinism is a condition where the pigment melanin does not get produced in the skin, hair and eyes. This is an inherited condition that is caused by a recessive allele.
If both parents have albinism what are the chances of the offspring being an albino child?
0%
25%
75%
100%
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1 markExtended Tier Only
The diagram below shows the process of sexual reproduction.
Which of the processes are shown by stages Q and R?
|
Q |
R |
|
| A |
meiosis |
mitosis |
| B |
mitosis |
mitosis |
| C |
meiosis |
meiosis |
| D |
mitosis |
meiosis |
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1 markTwo individuals are crossed. One is homozygous dominant (TT), the other heterozygous.
What will the genotypes of the offspring be?
all Tt
50% TT, 50% Tt
50% TT, 50% tt
25% TT, 50% Tt, 25% tt
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1 markA farmer is growing pea plants; the allele for tall plants is T and is dominant to the allele for dwarf plants, t.
She wants to know what cross she would need to carry out to produce a ratio of 1:1 tall to dwarf plants?
tt x tt
Tt x Tt
TT x Tt
Tt x tt
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1 markExtended Tier Only
Which row in the table shows a comparison between meiosis and mitosis?
| mitosis | meiosis | |
| A | produces 4 daughter cells | produces 2 daughter cells |
| B | produces genetically identical cells | produces cloned cells |
| C | daughter cells are diploid | daughter cells are haploid |
| D | two cell division occur | four cell divisions occur |
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1 markThe diagram shows how the sex of the offspring can be determined.
What are the sex chromosomes in gamete Q and the son R?
|
Q |
R |
|
|
A |
X |
XY |
|
B |
X |
XX |
|
C |
Y |
XY |
|
D |
Y |
XX |
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1 markFruit flies can have orange or red eyes.
If two orange flies are crossed, all of the offspring will have orange eyes.
If two red eyed fruit flies are crossed, the offspring have either orange or red eyes.
What can be concluded from these observations?
The allele for orange eyes is dominant.
Crossing an orange-eyed fly with a red-eyed fly will give a 1:1 ratio.
The allele for red eyes is dominant.
We could determine which allele is dominant only if we did further crosses that produced a 3:1 ratio.
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1 markThe inheritance of Huntington's disease is determined by a single gene. This gene has a dominant allele and a recessive allele. The allele for Huntington’s is dominant to the allele for non-sufferers of the condition.
The diagram shows the inheritance of Huntington’s in a family.
What is the probability that the next child from the same parents will have Huntington’s?
0%
25%
50%
75%
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