Reproduction, Heredity and Genetics, and Prenatal Development

ReproductionReproduction Process by which organisms create more

organisms of own kind. Male and female gametes or sex cells:

Sperm and ovum create zygote

Male Reproductive SystemMale Reproductive System

Testes: produce sperm Penis: Man’s external organ

The Female Reproductive The Female Reproductive SystemSystem

Ovaries produce ova. Ovum released approximately every 28 days. Moves through fallopian tubes where it may

be fertilized by sperm. Uterus prepares itself for conception. Unfertilized ovum shed; expelled through

cervix and vagina.

How and When Fertilization How and When Fertilization OccursOccurs

Menstrual Cycle Ovulation Fertilization Multiple Conception

Conceiving or Avoiding Conceiving or Avoiding ConceptionConception

Infertility and Assisted Reproductive Technology

In Vitro Fertilization Ethical Dilemmas of Baby Making Birth Control Methods

a. Contraception

b. Abortion

Infertility and Assisted Infertility and Assisted Reproductive TechnologyReproductive Technology

In vitro fertilization (IVF) Gamete intrafallopian transfer (GIFT) Zygote intrafallopian transfer (ZIFT) Intracytoplasmic sperm injection (ICSI) Preimplantation genetic treatment (PGT) Ovarian and sperm cryopreservation Sperm sorting (sperm separation) Embryo adoption

Ethical Dilemmas of Ethical Dilemmas of Baby MakingBaby Making

ARTs have significantly improved pregnancy rates

Questions:– How long should embryos develop in lab?– Who do embryos belong to?– What type of research is being conducted?

Birth Control MethodsBirth Control Methods

Abstinence Contraception Abortion

The Expanding Reproductive The Expanding Reproductive YearsYears

Menstruation can begin at 8 or 9 years of age; average 11 to 12

Advanced technology allows women to choose childbearing after menopause.

Heredity and GeneticsHeredity and Genetics

Heredity: our biological inheritance Genetics: the scientific study of biological

inheritance

The Human Genome ProjectThe Human Genome Project

The sequencing of the genetic blueprint of all the genes on their appropriate chromosomes

Genome is divided into chromosomes Chromosomes contain genes Genes are made of DNA

What are Chromosomes and What are Chromosomes and Genes?Genes?

Chromosomes Genes DNA Human genome Mitosis Meiosis

Determination of an Embryo’s Determination of an Embryo’s SexSex

46 chromosomes (23 pairs) 22 are similar in size and shape in both men and women: autosomes

23rd pair: sex chromosome, determines baby’s sex.

Principles of GeneticsPrinciples of Genetics Gregor Johann Mendel Dominant and Recessive Characteristics

a. Allele (dominant or recessive)

b. Homozygous characteristic

c. Heterozygous characteristics

d. Polygenic inheritance

Phenotypes and GenotypesPhenotypes and Genotypes

Genotype: Actual genetic makeup of organism

Phenotype: Observable characteristics of organism

Multifactorial TransmissionMultifactorial Transmission

Environmental factors interact with genetic factors to produce traits.

Sex-Linked Inherited Characteristics: Genes that are linked or appear on the same chromosome are inherited together: Sex-linked traits.

Genetic Counseling and Genetic Counseling and TestingTesting

Genetic Counseling: Helps parents find out risk of passing along a particular disorder or disease.

Genetic and Chromosomal Genetic and Chromosomal AbnormalitiesAbnormalities

Downs’ Syndrome: Occurs in 1 out of every 800 live births.

In 95% of all cases there are three copies of the 21st chromosome: trisomy 21

Extra chromosome alters course of development and causes physical characteristics.

Box: Human DiversityBox: Human Diversity

Prenatal diagnosis:

Amniocentesis

Ultrasonography

Fetoscopy

Chorionic villus biopsy

Maternal blood sampling

Prenatal DevelopmentPrenatal Development

Germinal Period: From conception to second week.

Characterized by growth of zygote and establishment of linkage between zygote and support system of mother.

Embryonic PeriodEmbryonic Period

From end of second week to eighth week. Rapid growth Establishment of a placental relationship

with mother Early structural appearance of all chief

organs Development of recognizable human body.

Development during embryonic Development during embryonic periodperiod

Cephalocaudal Proximodistal Critical Period

Fetal PeriodFetal Period

Begins with the ninth week and ends with birth

Characteristics: Organism called a fetus Major organ systems continue to develop

and assume their specialized functions.

Loss by MiscarriageLoss by Miscarriage

Miscarriage: organism is naturally expelled from uterus before it is viable.

Prenatal Environmental Prenatal Environmental InfluencesInfluences

Teratogens: Drugs and other chemical agents that can cause birth defects:

Smoking Marijuana Hard Drugs Alcohol Oral Contraceptives Toxins in environment and workplace

Maternal Infectious and Maternal Infectious and Noninfectious Diseases:Noninfectious Diseases:

Rubella and Other Agents Syphilis Genital Herpes HIV/AIDS Diabetes Maternal Sensitization: The Rh Factor Maternal Stress Maternal Age Maternal Nutrition and Prenatal Care