Two factors that have a large influence on the health of the developing baby are - Verified Answer: heredity environment Each sperm and ovum contribute - Verified Answer: 23 chromosomes to the new entity, which is a single celled Zygote sex of the zygote is determined by - Verified Answer: combination of X and Y chromosomes Ovum always contains - Verified Answer: X chromosome Sperm may contain - Verified Answer: X or Y chromosome If the ovum is fertilized by an X chromosome sperm, the zygote will be - Verified Answer: female if the ovum is fertilized by a Y chromosome sperm, the zygote will be - Verified Answer: male Journey Across the lifespan chapter 6 chromosomes carry the - Verified Answer: genes -genes transmit all the genetic info or hereditary characteristics from the parents to the child *Heredity is controlled by - Verified Answer: pairs of genes from both mother and father *pairing of genes is called - Verified Answer: Allele Genes are found on - Verified Answer: DNA *Dominant genes - Verified Answer: capable of expressing their traits over other genes Characteristics of dominant gene is inherited by 3 out of 4 offspring recessive genes - Verified Answer: can transmit their traits only if they exist in like pairs Eye color is an example of a trait - Verified Answer: that is affected by the dominant-recessive pattern of inheritance Defects carried on recessive genes - Verified Answer: Some examples: Sickle cell disease, Tay-Sachs disease, and hemophilia Journey Across the lifespan chapter 6 to inherit a recessive trait/disorder, the child must - Verified Answer: inherit the recessive gene from both parents *Karyotype - Verified Answer: chromosomal structure of an entity *Karyotyping - Verified Answer: mapping chromosomal structure can help predict the transmission of certain genetic disorders and is useful in counseling prospective parents *Genetic counseling - Verified Answer: guidance for prospective parents on the likelihood of genetic disorders in their future children *considered for individuals of specific cultural descents, such as sickle cell disease in African Americans Tay-Sachs disease in European Jewish descendants