Chapter Two Flashcards
Fragile-X syndrome is more common in males than in females. True or False
True
A person may transmit characteristics to offspring that he himself does not show. True or False
True
Some of a person’s inherited traits do not appear. True or False
True
This type of genetic transmission expresses the gene depending on whether it is from the mother or the father.
GENETIC IMPRINTING
This type of genetic transmission is carried on the X gene only, so boys are more likely to express the disorder because their Y chromosome is not able to counteract it. ____________
SEX-LINKED GENES or X-LINKED INHERITANCE
This type of genetic transmission occurs when multiple pairs of genes work together to form a characteristic. ____________
POLYGENIC INHERITANCE or GENE-GENE INTERACTION
This type of genetic transmission occurs because a certain gene always is expressed in favour of another one. ____________
DOMINANT-RECESSIVE GENES PRINCIPLE
This test is given during the 10th to 13th week by taking a sample from the placenta. Results are ready in 10 days, but it has a slight chance of miscarriage.
Chorionic villus sampling (CVS)
This is given about seven weeks into the pregnancy. It involves scanning the womb with soundwaves.
ultrasound
This is given during the 16th to 20th weeks using a needle to extract fluid. It is often used by older mothers and has a slight chance of triggering a miscarriage. It may take up to two weeks for results.
Amniocentesis
The fact that people give more attention to a happy baby is an example of _____ influence.
Evocative
Shy people avoiding parties & spending time in the library is an example of _____ influence.
active
The fact that parents who are genetically predisposed to be readers have lots of books and that their children’s genotype predisposes them to respond to books is an example of _____ influence.
passive
Because siblings’ experiences diverge as they grow (i.e., their nonshared environmental experiences increase), one would expect siblings to become ______.
less similar over time
What is evolutionary psychology
Branch of psychology that emphasizes the importance of adaptation , reproduction and ‘survival of the fittest’ in shaping behaviour
What is a chromosome
threadlike structure made up of DNA.
What is DNA
A complex molecule that has a double helix shape and contains genetic information
What is a gene
unit of hereditary information, a short segment of DNA.
What is mitosis
Cellular reproduction in which the cells nucleus duplicates itself with two new cells being formed, each containing the same DNA as the parent cell, arranged in the same 23 pairs of chromosomes
What is melosis
a specialized form of cell division that forms eggs and sperm (also known as gametes)
Fertilization
a stage in reproduction during which an egg and a sperm fuse to create a single cell, called a zygote
zygote
a single cell formed through fertilization
What is the dominant-recessive genes principle
in some cases, one gene of a pair always exerts its effects, it is dominant, overriding the potential of the the other gene, called the recessive gene. A recessive gene exerts its influence only if the two genes of a pair are both recessive.
Sex-linked gene
most mutated genes are recessive. When a mutated gene is carried on the X chromosome , the result is called x-linked inheritance. The implications for males may be very different from those for females. Remember males have only one x chromosome. Thus if there is an absent or altered, disease-relevant gene on the x chromosome, males have no back up. Thus must individuals who have x-linked diseases are males. Hemophilia and ragile x sydrom are examples of x-linked diseases
Genetic Imprinting
Genetic imprinting occurs when genes have differing effects depending on whether they are inherited from the mother or the father. A chemical process silences one member of the gene pair. When imprinting goes awry development is disturbed. e.g. beckwith-Wiedemann syndrome or Wilms tumor, a type of cancer
Genotype A
A persons genetic heritage, the actual genetic material present in each cell
Phenotype
The way an individual’s genotype is expressed in observed and measurable characteristics
Polygenic inheritence
Most characteristics are determined by the interaction of many different genes.
Chromosomal abnormalities
Sometimes a gamete is formed in which the male’s sperm or the female’s ovum do not have their normal set of 23 chromosomes. E.g. down syndrome and abnormalities of the sex chromosom
Down syndrome
a round face, flattened skull, extra fold of skin over the eyelids, a protruding tongue, short limbs and disabilities involving motor and intellectual development. This is caused by an extra copy of chromosome 21.
Sex- Linked Chromosomal Abnormalities
The most common is the presence of extra chromosome (either an x or Y0 or the absence of one x chromosome in females
Klinefelter syndrome
Chromosomal disorder in which males have an extra x chromosome, making them XXY instead of XY. Undeveloped testes and they usually have enlarged breasts and become tall, have a significant impairment in language, academic , attentional and motor abilities.
Fragile X syndrome
result from an abnormality in the x chromosome, which becomes constricted and often breaks. prominent ears, long face, high arched palate and soft skin. Mental deficiency often is an outcome, but may take the form of intellectual disability, learning disability or short attention span
Turner syndrome
chromosomal disorder in females in which either an x chromosome is missing, making the person XO instead of XX or part of on x chromosome is deleted. short. webbed neck. Might be infertile, difficulty in mathematics, but verbal ability is quite good.
XYY Syndrome
a chromosomal disorder in which the male has an extra Y chromosome. - a belief that it contributes to violence and aggression, but xyy males are no more likely to commit crimes
Gene-Linked Abnormalities
Abnormalities can be produced not only by an abnormal number of chromosomes but also by harmful genes.
Phenylketonuria PKU
a genetic disorder in which the individual cannot properly metabolize phenylalanine, an amino acid. PKU is easily detected and is treated by a diet that prevents an excess accumulation of phenylalanine. If untreated - hyperactivity and intellectual disability occur.
PKU nature-nurture
the environment can effect how this is played out, indicating nurture over nature.
sickle cell anemia
a genetic disorder most often in African Americans, impairs the functioning of the body’s red blood cells. usually the cells are shaped like a disc, in this disorder, the cell is shaped like a sickle that cannot carry oxygen properly and dies quickly. The body’s cells do not receive adequate oxygen, causing anemia and early death.
Spina Bifida
Neural tube disorder that causes brain and spine abnormalities , can receive corrective surgery at birth, orthopedic devices and physical therapy
Ultrasound
7 weeks and various other times. ultrasound somography is a procedure that uses high-frequency sound waves. The echo is transformed into a visual representation of the fetus’s inner structures. can detect structural abnormalities, number of fetuses and clues to baby’s sex
Fetal MRI
magnetic resonance imaging - powerful magnet and radio images to generate detailed images of organs and structure. MRI can provide more detailed images than u/s
Chorionic Villus Sampling
Between 9.5-12.5 weeks - CVS may be used to detect genetic defects and chromosomal abnormalities. Diagnosis takes 10 days. CVS - a small sample of the placenta is removed. There is a small risk of limb deformity
Amniocentesis
14-20 Weeks - sample of amniotic fluid is withdrawn by syringe and tested for chromosomal or metabolic disorders. Small risk of miscarriage.
Maternal Blood Screening
16-18 weeks maternal blood screening. Triple screen - measures three substances in mothers blood.
noninvasive prenatal diagnosis
NIPD is increasingly being explored as an alternative to procedures like chorionic villus sampling and amniocentesis. Uses brain imaging techniques - can detect Huntington’s Disease and cystic fibrosis
Fetal Sex Determination
CVS has been used to determine the sex of the fetus b/w 11-13 weeks.
Behaviour genetics
The field that seeks to discover the influence of heredity and environment on individual differences in human traits and development
Twin Study
A study in which the behavioural similarity of identical twins is compared with the behaviour similarity of fraternal twins
Adoption study
A study in which investigators seek to discover whether, in behaviour and psychological characteristics adopted childen are more like their adoptive parents, who provided a home environment, or more like their biological parents, who contributed to heredity. Or adoptive and biological siblings comparisons.
Passive genotype environment correlations
Correlations that exist when the natural parents, who are genetically related to the child, provide a rearing environment for the child
Evocative genotype-environment correlations
Correlations that exist when the child’s genetically influenced characteristics elicit certain types of environments
active (nice picking) genotype environment
Correlations that exist when children seek out environments they find compatible and stimulating
Shared environmental experiences
Siblings common environmental experiences, such as their parents personalities and intellectual orientation, the family’s socioeconomic status, and the neighbourhood in which they live
nonshared environmental experiences
The child’s own unique experiences, both within the family and outside the family, that are not shared by another sibling
Epigenetic view
theory that development is the result of an ongoing bidirectional interchange between heredity and environment
Gene x environment (G X E) interaction
the interaction of a specific, measured variation in the DNA and specific, measured aspect of the environment
