Quiz answers

• A population is drastically reduced in size by a catastrophic flood but recovers within a few generations. Which of the following genetic effects is not expected to occur?

  Increase in mutation rate.
• When DNA is replicated, one new strand can be synthesised continuously while the other must be synthesised in small fragments (Okazaki fragments). This is because:

  The template strands are antiparallel and DNA can only be synthesised in the 5'→3' direction.
• Name the two morphs which are common to members of the phylum Cnidaria

  Polyp and medusoid.
• Plasmodium spp. are apicomplexan parasites that can cause malaria in humans. Which protist clade do they belong to?

  Alveolates.
• Within a population, two alleles occur at locus A (referred to as A1 and A2). Allele A1 is completely dominant to A2. Individuals homozygous for A1 have a 70% probability of surviving to adulthood and produce four offspring on average. Individuals homozygous for A2 have a 90% probability of surviving to adulthood and produce six offspring on average. What is the relative fitness (to 2 decimal places) of the heterozygous genotype?

  0.52
• A Choanocyte is:


  a collar cell.
• What characteristics are shared by green algae and land plants?

  Cellulose cell walls, two membranes surrounding the chloroplasts and thylakoids arranged as granal stacks.
• What theory is thought to have led to the evolution of multicellular organisms?

  Colonial.
• The metatheria...


  includes the marsupials.
• Within a population, two alleles occur at locus B (referred to as B1 and B2). Individuals homozygous for B1 have a relative fitness of 0.8 and make up 25% of the population. If the average fitness of the population is 0.95, what proportion of individuals (to 2 decimal places) do you expect to be homozygous for B1 in the next generation?

  0.21
• Which phylum fits the following description: bilaterally symmetrical, open circulatory system, mantle, complex through gut, radula, metanephridia and visceral mass?

  mollusca
• The Testudinata (testudines) are...

  characterized by the tortoises, turtles and terrapins
• The amniotic egg has...

  four extraembryonis membranes
• What happens when all hox genes are inactivated in Drosophila?

  All segments are identical
• In the diagram above, where would be the best place to insert the reporter gene lacZ in order to measure the expression of GAL1?

  e

  
• The chlorophytes are important because:

  They gave rise to terrestrial plants
• The Komodo dragon is

  a lepidosaur
• Diplobiontic describes:


  a multicellular haploid and diploid stage (in algae).
• diatoms are...


  protists
• Alleles are most likely to persist in a population at low frequency for many generations if they are:

  deleterious and recessive
• he Oomycetes have cell walls composed of cellulose. They are:

  protists
• A captive population of animals is becoming inbred and it is decided to attempt genetic rescue. Which of the following source populations would carry the highest risk of outbreeding depression?

  An inbred captive population of a different subspecies
• The Actinopterygii are the

  Ray-finned fish
• Archaeopteryx...


  had teeth
• In a population of organisms, allele frequencies are measured at three loci, A, B and C. Each locus contains two alleles. At locus A p=0.1; at locus B p=0.9; at locus C p=0.2. What is the expected heterozygosity (to 2 decimal places) for the population on the basis of these figures?

  0.23
• The squamates are


  The snakes and lizards.
• What is common to the Placozoa, Cnidaria, Ctenophora and Porifera?


  They are diploblastic organisms.
• Insects were critical to the evolution of angiosperms because:

  they facilitated the transport of pollen over long distances.
• Approximately how many living species of vertebrates are there on our planet?

  >50,000
• The chordates are...


  Deuterostomes
• The three chordate subphyla are...

  the Urochordates (Tunicates), Cephalochordates and Craniates.
• Two processes that can result in paedomorphosis are...

  eugenesis and neoteny
• The Myxini are the least derived surviving craniate lineage. They are the 

  The Hagfish.
• Key characteristics of the chordates are...

  dorsal hollow nerve cord, post-anal tail, notochord and pharyngeal gill slits.
• The Petromyzontida represent the oldest living lineage of vertebrates. They are the ...

  The Lampreys
• The earliest known mineralised vertebrate structures are

  Conodont dental elements.
• Jaws are believed to have evolved from

  The first gill arches
• The gnathostomes are...


  Vertebrates with jaws
• Dunkleosteus is a fossil gnathostome with an incredible bite force of 8000 PSI at the tip of its jaws. Dunkleosteus was a ...

  Placoderm
• Gnathostomes are believed to have emerged...

  About 470 MYA