Chapter 2 pg. 34-63 - Heredity, Prenatal Development and Birth Flashcards
Define Genes
Specific sequence of nucleotides and are recipes for making proteins
Distinguish between mitosis and meiosis, genotype and phenotype, homozygous and heterozygous, and dominant and recessive
Mitosis - Cell’s nucleus making an exact copy of all the chromosomes and splitting into two new cells
Meiosis - Gamete’s chromosomes duplicate, then divide twice resulting in four cells containing half the genetic material of the original gamete
Most known genetic disorders are linked in what way?
They are dominant gene-linked, recessive gene disorders are less common
Who are at greater risk for sex-linked disorders?
Men, as they only have one X chromosome
Define polygenic and incomplete dominance
Polygenic - Meaning a characteristic is the result of several genes
Incomplete Dominance - When the dominant gene does not completely suppress the recessive gene (seen in carriers of the sickle gene)
What is the relationship between age of the mother and chromosomal abnormalities?
As the mother ages, the ovum is more likely to suffer abnormalities due to longer term exposure
What is Turner Syndrome?
When part or all of one of the X chromosomes is lost and the resulting zygote has an XO composition
Describe the function of genetic counseling and why individuals may seek genetic
counseling
Genetic counseling is a service that assists individuals to identify, test for and explain potential genetic conditions that could adversely affect themselves or their offspring
Define behavioral genetics, describe genotype-environment correlations and genotype-environmental interactions, and define epigenetics
Behavioral Genetics - The scientific study of the interplay between the genetic and environmental contributions to behavior (often referred to as nature/nurture debate)
Describe genotype-environment correlations
Passive genotype-environment correlation - Children inherit genes that enable success and the given environmental encouragement to engage in these actions
Evocative genotype-environment correlation - How the social environment reacts to individuals based on inherited characteristics (ex: outgoing or shy temperament will affect how one is treated by others)
Active genotype-environment correlation - When individuals seek out environments that support their genetic tendencies (ex: kid who’s musically inclined seeks out music instruction)
What is epigenetics?
Studies modifications in DNA that affect gene expression and are passed on when the cells divide
- Environmental factors (stress, nutrition, teratogens) are thought to change expression by switching genes on and off
- Why monozygotic/identical twins may differ in gene expression with age
What are the three periods of prenatal development?
Germinal, Embryonic, Fetal
What is the Germinal Period of prenatal development?
From conception to implantation of fertilized egg in the lining of the uterus; about 14 days in length
- Organism begins cell division via mitosis
