IB Biology Topic 3 Review

What does the karyotype below correspond to?

• normal male
• A normal female
• A female with Down syndrome
• A male with Down syndrome

What can be concluded from the karyotype provided below?
 

• There was non-disjunction during meiosis in the mother
• There was non-disjunction during meiosis in the father
• The fetus is male
• The fetus is female

Which of the following statements about homologous chromosomes is correct?

• Each gene is at the same locus on both chromosomes
• They are two identical copies of a parent chromosome which are attached to one another at the
  centromere
• They always produce identical phenotypes
• They are chromosomes that have identical genes and allele

Which process and type of resulting cells are represented?

• mitosis, gametes
• mitosis, body cells
• meiosis, gametes
• meiosis, body cells

Which best describes the process shown?

• mutation in which the DNA content of the gene is ltered
• segregation of sister chromatids
• condensation and segregation of the alleles
• crossing-over which alleles are exchanged

In which ways can genetic engineering can improve crops

• Make them pest or drought resistant

• Make them more nutritious

• Make them larger

• All answers are correct

What is a genetic test cross?

• Testing a suspected homozygote by crossing it with a known heterozygote
• Testing a suspected heterozygote by crossing it with a known heterozygote
• Testing a suspected homozygote by crossing it with a known homozygous dominant
• Testing a suspected heterozygote by crossing it with a known homozygous recessive

If an organism that is homozygous recessive for a trait is crossed with a heterozygote, what is the chance of getting a homozygous recessive phenotype in the first generation?

• 0%
• 25%
• 50%
• 100%

A man of blood group A and a woman of blood group B have a child.  If both are heterozygous for the gene, what are the chances of them having a child with blood group B?

• 0%
• 25%
• 50%
• 75%

If a man has blood group O and a woman has blood group AB, what is the probability that their child will be blood group O?

• 0%
• 25%
• 50%
• 100%