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WorksheetsQB1 Genetics and Evolutionary Biology
Total questions: 20
Worksheet time: 2hrs 40mins
The S phase of the cell cycle is characterised by:
Alignment of chromosomes at the mitotic plate
DNA synthesis
Separation of homologous chromosomes
Cytokinesis
Which diagram represents anaphase I of meiosis?
I
II
IV
V
Which diagram represents prophase I of meiosis?
I
III
IV
VI
In a diploid cell with 10 chromosome pairs (2n = 20), how many sister chromatids will be found in a nucleus at prophase of mitosis?
5
10
20
40
Mendel’s Principle of Segregation refers to:
The segregation of alleles of different genes in an independent manner
The concealment of an allele by the presence of another
The separation of alleles of one gene from each other during meiosis
The failure of chromatids to separate during meiosis
A red-haired chicken (RR) who is homozygous for the dominant allele is crossed with a red-haired chicken who is heterozygous (Rr). Using a Punnett square, determine the genotypic ratio of the F1 generation.
4 red-haired: 0 yellow-haired
2 RR: 2 rr
4 Rr
2 RR: 2 Rr
Red-green colour blindness shows an X-linked recessive pattern of inheritance. A woman whose father was red-green colour blind marries a man who has the condition. What proportion of their sons would have the disease?
100%
75%
50%
25%
Round seeds (R) is dominant to wrinkled seeds (r), and yellow seeds (Y) is dominant to green seeds (y). A true-breeding (homozygous) plant with round and yellow seeds is crossed to a true-breeding (homozygous) plant with wrinkled and green seeds. What is the genotype of the F1 progeny?
RRYY
100% round and 100% yellow
rryy
RrYy
When the phenotype expresses clear characteristics of both alleles, this is referred to as:
Incomplete dominance
Dominance
Recessive
Co-dominance
All of the following are features of a prokaryotic cell EXCEPT?
Chromosome
Nucleoid
Endoplasmic reticulum
Ribosomes
What process describes chromosomes not segregating correctly during cell division?
Crossing over
Dominance
Non-disjunction
Independent assortment
Based on the pedigree chart shown below, determine the mode of inheritance.
X-linked dominant
X-linked recessive
Y-linked
Autosomal recessive
What is the mode of inheritance for this trait?
Autosomal dominant
Autosomal recessive
X-linked dominant
X-linked recessive
What is the genotype of individual 2 in the pedigree, using R/r as nomenclature for the trait?
RR
XRXr
XrXr
Rr
Individual 10 in the pedigree marries an individual who is heterozygous for this trait. They have two sons and two daughters. What is the probability of their daughters displaying the trait?
100%
25%
50%
0%
Which term describes the absence of one chromosome in an otherwise diploid individual?
Aneuploidy
Trisomy
Hypoploid
Monosomy
What accounts for equal expression of genes on the sex chromosome, despite the fact that males and females have an unequal complement of sex chromosomes?
Incomplete dominance
Independent assortment
Dosage compensation
Sex limited inheritance
Which of the following is TRUE about the XX-XY sex determination system in humans?
Female offspring are typically XO and the single X chromosome is inherited from the mother.
Male offspring have one X chromosome and it is inherited from their mother.
Female offspring have one X chromosome and one Y chromosome.
Male offspring have one X chromosome and it is inherited from their father.
If non-disjunction of Chromosomes 18 occurs at the first meiotic division followed by normal disjunction at the second meiotic division, what will be the resultant gametes be?
Four gametes: two containing an extra chromosome 18, and two with no chromosome 18
Four gametes: two containing an extra chromosome 18, and two containing one chromosome 18
Two gametes: both containing one chromosome 18
Four gametes: two containing one chromosome 18, one containing an extra chromosome 18, and one with no chromosome 18
Which of the following is FALSE about mosaic expression?
In a heterozygous female, each cell expresses either allele
It occurs in females who are homozygous for an X-linked trait.
It leads to intermediate phenotypes
The inactivated X chromosome forms a Barr body
