In humans, there are three alleles that determine blood groups, namely IO, IA and IB. The frequency of the IO allele in a particular population was found to be 0.72. There was an equal abundance of the remaining two alleles.
What would the frequency of the IB allele be in this population?
0.44
0.28
0.14
0.07
A game farm in South Africa has a population of about 5 000 large antelope called Kudu. Kudu bulls have large, spiralled horns which draw the attention of trophy hunters that frequently visit the game farm.
The antelope are all kept in a large, fenced-off area consisting of open grassland habitat.
Could this be considered an example of a stable gene pool?
No, since there will be a selective pressure to increase the allele frequency for antelope with large horns
No, since there will be a selective pressure for antelope with smaller horns
Yes, it is a large population of antelope with an equal chance to mate with each other
Yes, it is a large population located in a habitat that enables random matings between antelope of different phenotypes
Which of the following applies to the process of evolution by natural selection?
II only
I, II and III
II and IV only
I, II, III and IV
What would be the most accurate description of the following graphs?
|
I |
II |
III |
|
| A |
Stabilising selection as giraffes with longer necks are selected for |
Directional selection as larger and smaller turtles are selected for |
Disruptive selection as cacti with a medium spine density are selected for |
| B |
Directional selection as giraffes with longer necks are selected for |
Disruptive selection as larger and smaller turtles are selected for |
Stabilising selection as cacti with a medium spine density are selected for |
| C |
Stabilising selection as giraffes with medium neck lengths are selected for |
Disruptive selection as larger and smaller turtles are selected against |
Directional selection as cacti with medium spine density are selected for |
| D |
Directional selection as giraffes with medium neck lengths are selected for |
Stabilising selection as larger and smaller turtles are selected against |
Disruptive selection as cacti with medium spine density are selected for |
What is the most important requirement for speciation to occur?
A geographical barrier is needed to separate different species from one another so that natural selection can occur
Mutations occurring within a population which brings about slight changes to the phenotype of individuals
Reproductive isolation must occur within a population which can be brought about by a range of different barriers
Organisms must be able to find a suitable mate within their habitat in order to pass on their genetic information
Which of the following would be the best description of the events depicted in the diagram?
A geographical barrier separated two populations of the same species and over time they adapted to new conditions in their environment
A temporal barrier meant that the two populations were not able to reproduce during the same season anymore and formed new species
A geographical barrier separated two populations of different species and over time they adapted to seasonal differences in their habitat
A temporal barrier separated two populations which led to behavioural changes that resulted in speciation
A team of palaeontologists discovered the remains of an insect-like organism trapped in amber, which was found in rock layers believed to be about 180 million years old. As they dug deeper into the older layers of rock, they made several further discoveries. Their findings are shown in the diagram below.
What conclusion can be drawn from the information given?
The changes observed in these populations occurred gradually from 180 million years ago until 500 million years ago.
The original population changed dramatically over time which led to several different species forming
There were several large speciation events that occurred within a short period of time within these populations
Speciation occurred gradually, with many small changes accumulating over a long period of time
Which of the following would not apply to the punctuated equilibrium theory of speciation?
A volcanic eruption on an island wipes out most individuals of a particular species of rodent
A change in vegetation favours field mice with a coat colour that is a deeper shade of brown
A bacterial colony in the human body is treated with antibiotics which kills off all susceptible individuals
A swarm of locusts arrive at a newly planted field containing a wheat variety that requires very robust mouth parts to bite through the leaves and stems
Why can polyploidy be considered an advantage to some plant species?
Meiosis can occur more rapidly, leading to an increase rate of gamete formation
It increases the diversity of alleles within a population and reduces the impact of recessive mutations
The polyploid plant can reproduce more successfully with diploid plants from the same species
It can lead to the occurrence of more purebred individuals within a plant population
Which of the following examples would be a useful application of comparing allele frequencies between populations?
I only
III only
I and II only
I and II only
