What are monozygotic (MZ) twins?
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What are monozygotic (MZ) twins?
Monozygotic (MZ) twins are twins resulting from one egg splitting post-fertilisation, sharing 100% of their DNA, and thus considered genetically identical.
What are dizygotic (DZ) twins?
Dizygotic (DZ) twins are twins resulting from two separate eggs fertilized by two separate sperm, sharing 50% of their DNA, and thus considered genetically similar, not identical.
Why are MZ twins useful for genetic similarity research?
MZ twins, sharing 100% of their DNA, are useful to serve as each other's control group in research, aiding in investigating the biological basis of behaviour.
What is the purpose of twin studies in genetic research?
The purpose of twin studies is to compare the concordance rates of behaviours between MZ and DZ twins to determine if behaviour has a biological basis or is influenced by the environment.
What is a proband in twin studies?
A proband is the first participant used for comparison purposes e.g. in twin studies one twin is the proband who is then compared to their twin for the behaviour being measured.
True or False?
Family studies look at inherited traits within the same family i.e. people can inherit conditions which predispose them to particular behaviours or conditions.
True.
Family studies look at inherited traits within the same family i.e. people can inherit conditions which predispose them to particular behaviours or conditions.
What is the significance of adoption studies in genetic research?
Adoption studies compare concordance rates between adopted children and their biological versus adoptive parents to discern the impact of genetics versus environment on behaviour.
McGuffin et al. (1996) conducts which type of study to investigate the heritability of depression?
a) twin study
b) adoption study
c) family study
a.
McGuffin et al. (1996) investigates a twin study to examine the heritability of depression.
Which type of study is Brunner et al. (1993):
a) twin study
b) adoption study
c) family study
c.
Brunner et al. (1993) is a family study.
True or False?
Adopted children share genes with their adoptive parents, suggesting that similarities between them are influenced by genetics.
False.
Adopted children do not share genes with their adoptive parents, suggesting that similarities between them are influenced by the environment, not genetics.
What is the aim of the McGuffin et al. (1996) study?
The aim of the McGuffin et al. (1996) study is to investigate the concordance rates for depression in MZ and DZ twins to assess the heritability of depression versus its environmental influence.
True or False?
The participants of the McGuffin et al. (1996) study are 20 siblings in New York as suffering from depression.
False.
The participants of the McGuffin et al. (1996) study are 177 twin probands registered in London as suffering from depression, along with their same-sex twin siblings.
In McGuffin et al. (1996), are the interviewers aware or unaware (blind) as to whether the twin is MZ or DZ ?
In the McGuffin et al. (1996) study, the interviewers are unaware (blind) as to whether the twin is MZ or DZ .
In the McGuffin et al. (1996) study, what are the concordance rates for depression in the MZ and DZ twins?
In the McGuffin et al. (1996) study, the concordance rates for depression in MZ twins is 46% and 20% in DZ twins, suggesting a significant heritable component to depression.
Why is the use of a longitudinal design a strength of the McGuffin et al. (1996) study?
McGuffin et al.'s use of a longitudinal design allows for robust tracking of participants, enhancing the validity of the findings.
Why is it a limitation of McGuffin et al.'s (1996) study that the concordance rate for depression in MZ twins is not 100%?
It is a limitation of McGuffin et al.'s (1996) study that the concordance rate for depression in MZ twins is not 100%, as it suggests depression is not completely genetic and other factors (e.g. the environment), may play a role.
What is the aim of Brunner et al.'s (1993) study?
The aim of the Brunner et al. (1993) study is to investigate the violent, anti-social behaviour observed in specific males of a large family in the Netherlands and the link between this behaviour to a genetic condition transmitted via the MAOA gene.
True or False?
The Brunner et al. (1993) study is a family study of 5 males in the Netherlands, all of whom had the same genetic condition, transmitted via the X chromosome on the MAOA gene.
True.
The Brunner et al. (1993) study is a family study of 5 males in the Netherlands, all of whom had the same genetic condition, transmitted via the X chromosome on the MAOA gene.
What conclusion do Brunner et al. (1993) draw from their family study?
The conclusion drawn by the Brunner et al. (1993) family study is that the dysfunctional MAOA gene may be linked to irregular serotonin metabolism, aggressive behaviours, and low IQ, termed 'Brunner syndrome.'
True or False?
A limitation of Brunner et al. (1993) is that it uses only one extended family.
False.
It is a strength that Brunner et al. (1993) uses one extended family. This is because family members are used as control samples, validating the idea that the males’ behaviour was genetic rather than due to the environment.
In Brunner et al. (1993), what are the ethical concerns surrounding consent?
In Brunner et al. (1993), there are ethical concerns surrounding consent due to the participants' low IQ, potentially compromising the study's ethical integrity.