QB1 Genetics and Evolutionary Biology

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