Child development ch.2

Hereditary

- transmission of biological characteristics from one generation to another

Genes

- Basic unit of heredity

- contains instruction that guide formation of all individual traits- physical traits (eyes, hair, certain diseases) and psychological traits ( how person responds to environment, communicate with people

genotype

- exact genetic makeup, a particular set of genes that individual has inherited

Phenotype

all observable, physical, behavioral, and psychological traits the person actually develops

Natural Selection

survival and evolvement, adapting to one's environment to survive

- people with phenotypes that are adaptive to their particular environmental conditions have an increased chance or surviving and reproducing.

Emergence of shorter pregnancies

- Females with longer pregnancies were more likely to be hurt through brith process, less likely to survive, and less likely to have additional children

Zygote

- fusion from an egg and sperm

- 46 chromosomes (23 Mom and 23 Dad)

Germ cells

- sperm and ova that have 23 unpiared chromosomes

Somatic cells

All other cells of the body (skin cells, bone cells, blood cells)

- 46 cells in 23 pairs identical to chromosomes in the zygote

- Made by mitosis

Germ cells are created by what

Meiosis

Sex determination

- women XX

- men XY

Allele

Specific form of a gene

Homozygous

parents with same allele for trait

heterozygous

parents with different allele for trait

Dominant allele

An allele that is expressed when an individual possesses two different alleles for the same trait

Recessive allele

An allele that is not expressed when an individual possesses two different alleles for same trait

Carriers

can pass the allele to their offspring

Codominance

traits that is determined by two alleles is different from the trait produced by either of the contributing alleles alone

Polygenetic inheritance

contribution of a variety of genes - sometimes very many to a particular trait

Mutation

alteration in the molecular structure of an individuals DNA

Gene pool

total variety of gentic information possessed by a sexually reproducing offspring

Examples of recessive disorders

phenylketonuria and sickle cell anemia

preconception tests

Analysis of parents DNA using blood or saliva samples

Prenatal tests

tests that are used to analyze DNA of an embryo or a fetus to determine genetic disorders

Amniocentesis

A prenatal test that involves inserting a needle into the uterus and withholding amniotic fluid containing fetal cells that can be analyzed for genetic disorders

Chorionic villus sampling (CVS)

Prenatal test that samples tissue from the placenta to analyze for genetic disorders

noninvasive prenatal diagnosis

taking a sample with the mothers blood, at no risk for the mother or the fetus to screen for genetic disorders like Down Syndrome, Cystic Fibrosis, hemophilia

Down Syndrome

- creates extra genetic material on chromosome 21

- mainly associated with older parents specifically the mother

Heritability

measure of a degree to which a variation in a particular trait among individuals in a specific population is related to genetic differences among those differences

Kinship studies

Studies that use naturally occuring conditions provided by kinship relations to estimate gentic and environemntal contributions to a phenotypic trait

Family study

study that compares members of the same family to determine how similar they are on a given trait

Twin study

groups of monozygotic (identical) and dizygotic (fraternal) twins of the same sex are compared to each other and to other family members for similarity on a given trait

Adoption study

study that focuses on children who have been reared apart from their biological parents

Sickle cell anemia

- come from both parents and homozygous for it have seriously abnormal red blood cells

- Normal blood cells ( smooth and disk shape)

- Sickle cell ( rigid and sticky)