• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Polygenic Lab

Extracts from this document...

Introduction

Introduction Human Height Polygenic traits are not expressed as absolute or distinct characters as was the case with Mendel's pea plant traits. Instead, polygenic traits are recognizable by their expression as a continuous variation. Height in humans is a polygenic trait. If you line up the entire class a range of variation is apparent, with an average height at the high point in the middle. Traits showing continuous variation are usually controlled by the additive effects of two or more separate gene pairs. This is what gives polygenic traits so many alleles and, therefore, so many genotypes. Usually polygenic traits are distinguished by traits usually quantified by measurement rather than counting, two or more gene pairs contributing to the phenotype, or phenotypic expression of polygenic traits varying over a wide range. ...read more.

Middle

So... If human height is a polygenic trait and polygenic traits have phenotypic variation, then human height should have a phenotypic variation. Human Ear Lobes If ear lobes are determined by a one gene trait and one gene traits have two alleles, then ear lobes are decided by two alleles making it have two genotypes. Data (Human Height) Biology class (period 3) Height (cm)(tens place) Height (cm)(ones place) 180 1,1,3 170 1,3,3,4,8 160 0,3,4,5,6,6,6,6,7,9 150 5,5,6,6,8 Biology class (period 1-3) Height (cm)(tens place) Height (cm)(ones place) Period 1 Period 2 Period 3 180 0,1,1 0,6,6,7,8,8 1,1,3 170 0,0,0,1,2,2,3,4,5,5,5 0,2,3,4,6,6,7 1,3,3,4,8 160 0,2,3,3,4,5,7,8,9,9 1,2,2,5,5,6,6,8,8,8,8 0,3,4,5,6,6,6,6,7,9 150 4,7,9 7,7 5,5,6,6,8 10 people Height (cm)(tens place) ...read more.

Conclusion

where a simple height gene has mutated and is present in many copies (alleles) and all alleles contributing to the height. There are so many alleles controlling this one trait that when they all get mixed up lots of outcomes are available. Human Ear Lobes My hypothesis that stated, if ear lobes are determined by a one gene trait and one gene traits have two alleles, then ear lobes are decided by two alleles making it have two genotypes, was true. If ear lobes are only determined by one gene then there are going to be two alleles. There is not a very big variation in the ear lobes because it is one gene trait, so no matter how you arrange the two alleles one is going to be dominant and one is going to be recessive, making only two outcomes. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. IB Genetic Lab

    length of arm-span and height of females from age 5 to 50 in centimeters collected from personal surveys The mean for the length of arm-span and height can be calculated using the following equation: Let A represent the average length of arm-span of females. Let B represent the average height.

  2. Genetic Variation

    Some more barriers include addition, removal, temporal, reproductive, and behavioral. An example of this may be in reproductive barriers in which two species cannot mate because of differences on a reproductive base. In small populations, random changes in the frequency of alleles refer to genetic drift.

  1. Simpson Diversity Lab

    DATA COLLECTION: Table 1: Number of plant species found in both fields: Field Quadrat Species Rugby 1 - 10 dandelions (� 2) - 6 plantain (� 1) - 2 crab grass (� 1) - 4 unknown (� 1) 2 - 12 dandelions (� 2)

  2. IB Genetic Unit Notes

    4.3.5: Explain how the sex chromosomes control gender by referring to the inheritance of X and Y chromosomes in humans. Females have XX chromosomes. Males have XY chromosomes. Just stick these into a punnet grid and show that 50% of boy or girl.

  1. Should Animals have the same rights as Humans? Both animals and humans exhibit behaviours ...

    In addition, the data could be seen as invalid because the dogs that participated were strays, their breed or background was unknown. Knowing their background would enable one to determine what sort of conditioned reflexes have already been established in relation to a given stimulus and to theorise on how this might affect the results.

  2. Comparing the Sexy Sons Hypothesis and the Pathogen Avoidance Models Effects on Sexual Selection

    Though I have talked about male mate guarding, the same concept applies to females in the context of sexual selection as females must be choosy with males (limited males) and expending too much time with non fit males (time expended vs reward)

  1. Sleep is a normal part of human life. Investigate the neurobiological basis of normal ...

    Sleep debt results in diminished abilities to perform high-level cognitive functions. Neurophysiological and functional imaging studies have demonstrated that frontal regions of the brain are particularly responsive to homeostatic sleep pressure. Scientists do not agree on how much sleep debt it is possible to accumulate; whether it is accumulated against

  2. Biotechnology Assignment: Genetic Screening/Testing

    or a person?s ancestry. Normally, every person carries two copies of every gene (with the exception of genes related to sex-linked traits, which are only inherited from the mother by males), one inherited from their mother, one inherited from their father.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work