Week 2: Genetic Bases for Child Development Flashcards
(26 cards)
What are Gametes?
Sex cells - eggs and sperm - each gamete has 23 chromosomes
What are chromosomes? (Book)
Thread like structures in the nucleus of the cell that contains our genetic material
What are autosomes?
The first 22 pairs of chromosomes all of which are relatively the same size
What are sex chromosomes?
The 23rd pair of chromosomes that determines the sex of the baby
What is DNA? (words)
A molecule composed of four nucleotide bases (each chromosome consists of one molecule): Adenine + Thymine and Guanine + Cytosine
What is a gene? (sentence)
A group of nucleotide bases that provides a specific st of biochemical instructions
What is a phenotype?
The physical, behavioural and psychological features that are the result of the interaction between one’s gemes and the environment
What is a genotype?
A person’s complete hereditary makeup
What is an allele?
a variant or specific form of gene - every person inherits two alleles for each gene from each parent
What is homozygous?
the condition in which the alleles for hereditary characteristics are the same
What is heterozygous?
the condition in which the allels for hereditary characteristics are different
What is incomplete dominance?
A situation where one allele does not dominate another completely - the phenotype falls between the phenotype associated with either allele
EX. intelligence, personality, characteristics, height
What is heritability?
An estimate of the proportion of trait variability in a population that is determined by genetic difference - accounts for differences within groups NOT individuals
EX. Heritability of height is 90% meaning that 10% is due to genetic factors
What are some of the most common homozygous recessive allele disorders?
Cystic Fibrosis
Phenylketonuria (PKU)
Tay-Sachs Disease
Sickle-cell disease
What is the one serious dominant allele disorder?
Huntingtons Disease
Found on chromosome 4
Degeneration of the nervous system
What is the most common type of sex linked disorder?
Hemophilia: blood does not clot easily which can lead to excessive bleeding
What are other common sex linked disorders?
- Klinefelter’s Syndrom XXY
- XYY Complement
- Turner’s Syndrome X
- XXX Syndrome
What is Down Syndrome?
Caused by extra 21st chromosome
- intellectual disability and distinctive appearance
- increased chances of having a child with down syndrome, the older the egg
What is behavioural genetics?
branch of genetics that deals with inheritance of behavioural and psychological traits (many of which fall along a continuum)
What is Polygenic inheritance?
When phenotypes result of the combined activity of separate genes (more than 2+ genes are involved)
EX. Height
What is a reaction range?
the phenomenon that a particular genotype can interact with various environments to produce a range of phenotypes i.e. switching on and off certain traits
EX. girls can menstruate at a younger age if they have had a stressful childhood
What is epigenesis? “on or above genes”
Continuous interplay between genes and multiple levels of the environment
What is the heritability coefficient?
Estimates the extent to which differences among people reflect heredity
What is methylation?
The process by which experience changes the expression of DNA - the genetic code is preserved by the gene is turned OFF
