Transcript Chapter 3 PowerPoint

Reproduction, Heredity and Genetics,
and Prenatal Development
Reproduction
 Process
by which organisms create more
organisms of own kind.
 Male and female gametes or sex cells:
 Sperm and ovum create zygote
Male Reproductive System
 Testes:
produce sperm
 Penis: Man’s external organ
The Female Reproductive
System
 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
Occurs
 Menstrual
Cycle
 Ovulation
 Fertilization
 Multiple
Conception
Conceiving or Avoiding
Conception
 Infertility
and Assisted Reproductive
Technology
 In Vitro Fertilization
 Ethical Dilemmas of Baby Making
 Birth Control Methods
a. Contraception
b. Abortion
Infertility and Assisted
Reproductive 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
Baby 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 Methods
Abstinence
 Contraception
 Abortion

The Expanding Reproductive
Years
 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 Genetics
 Heredity:
our biological inheritance
 Genetics: the scientific study of biological
inheritance
The 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
Genes?
 Chromosomes
 Genes
 DNA
 Human
 Mitosis
 Meiosis
genome
Determination of an Embryo’s
Sex
 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 Genetics
 Gregor
Johann Mendel
 Dominant and Recessive Characteristics
a. Allele (dominant or recessive)
b. Homozygous characteristic
c. Heterozygous characteristics
d. Polygenic inheritance
Phenotypes and Genotypes
 Genotype:
Actual genetic makeup of
organism
 Phenotype: Observable characteristics of
organism
Multifactorial 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: Sexlinked traits.
Genetic Counseling and Testing
 Genetic
Counseling: Helps parents find
out risk of passing along a particular
disorder or disease.
Genetic and Chromosomal
Abnormalities
 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 Diversity
 Prenatal
diagnosis:
Amniocentesis
Ultrasonography
Fetoscopy
Chorionic villus biopsy
Maternal blood sampling
Prenatal 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 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
period



Cephalocaudal
Proximodistal
Critical Period
Fetal 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 Miscarriage
 Miscarriage:
organism is naturally expelled
from uterus before it is viable.
Prenatal Environmental
Influences
 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
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