LAMC CD 1Dr. Allen Week 3

Genes & Human Reproduction

• DNA- double helix molecule that carries genetic information on chromosomes.

• Gene- is a section of the DNA.

• For each pair of chromosomes, the genes for a trait are in the same locations…alleles.

• Genotype

• Phenotype

• The genotype environment influences the developmental opportunities of the phenotype.

• Dominant gene- a powerful allele whose characteristics are expressed in the phenotype...

• Recessive gene- a weak allele whose characteristics are expressed in the phenotype...

• Polygenic inheritance- the case in which a trait (phenotype) is determined by…

• Mitosis- involves autosomes…

• Meiosis- the process of cell division that results in the production of gametes.

• Gametes…

• Gonads…

Conception & Fertility/Infertility

• Ovulation- release of an egg (ovum) from the ovary…

• Conception

Theory called homunculus…

Identical twins (Monozygotic)

• Conception occurs with...

• Identical twins can develop their own…

Fraternal Twins (Dizygotic)

• Conception occurs with...

• Always develop individual...

Behavior Genetic Theory

• Environmental & genetic factors that account for individual in personality & behavior.

• Shared vs. non-shared environments

• Heritability- value ranges from 0 to 1.00; the higher the heritability, the more the characteristic is believed to be influenced by genes

Gene environment interactions

• The environment influences how genes are expressed in the phenotype

• Epigenesis: development results from the bidirectional interactions between the environment & genotype (DNA)

• Ex 1: menstruation begins at 11-16 years

• Ex 2: adult twins; one develops breast cancer