Fertilization and Development in Humans

Fertilization ______________ the ______________ of the sperm and egg ______________ in the ____________________________ In humans, ______________ and ______________ is ______________ in the body of the ______________. At the moment of fertilization, the egg develops a ____________________________ around itself to prevent other ______________ from penetrating. A fertilized egg is called a ______________ Fertilization Fusion (joining) nuclei Oviducts or fallopian tubes Fertilization development Internal female Protective membrane sperm zygote = + egg sperm zygote Name: ______________ ______________ ______________ Chromosome ______________ ______________ ______________ Number FERTILIZATION RESTORES THE SPECIES NUMBER OF CHROMOSOMES 23 23 46

As the Egg Travels 2 2 splits more One egg One sperm Fraternal Twins Identical Twins Fertilization of _____ eggs by ___ sperm Female releases __________ than one egg during ovulation Fertilized zygote __________ into 2 identical embryos Only __________ was fertilized by _______________ 2 2 splits more One egg One sperm

Advantages / Disadvantages of Internal Fertilization Avoid hazards of the _______________ Sperm can only fertilize an egg for a _______________ period of time Eggs are well _______________ Sperm live a _______________ time because they store _______________ food. environment short protected short little

Gastrulation and differentiation Animal Development (A) (B) 1) __________ 2) __________ 3) __________ 4) __________ sperm egg zygote 2 cell embryo 11)__________ Mesoderm (C) 9) __________ ectoderm 10)__________ endoderm gastrula blastula 8 cell embryo 4 cell embryo 8) __________ 7) __________ 6) __________ 5) __________ _____________________________________ Fertilization Cleavage by mitosis Gastrulation and differentiation

Cleavage __________ - after fertilization, the __________ divides by __________ to produce __________ cells Cell division continues without __________ Once cleavage begins, the zygote is called an __________ __________ - hollow ball formed by the embryo __________ - when the embryo attaches to the ____________________ cleavage zygote mitosis two growth embryo blastula implantation Uterine lining

Gastrulation differentiation different tissues organs GENES PROTEINS _______________ - embryo cells become __________ from one another They form __________ and __________ of the new organism DIFFERENT __________ TURN ON OR OFF IN CERTAIN CELLS TO PRODUCE DIFFERENT __________ THE _____________ A CELL MAKES, DETERMINE ITS _______________ Three embryonic germ layers of the embryo __________ - develops into __________ and ____________________ __________ - develops into __________ and __________ systems __________ - develops into __________ other systems like the __________ and __________ systems tissues organs GENES PROTEINS job or function PROTEINS ectoderm skin Nervous system endoderm digestive respiratory mesoderm all reproductive circulatory ectoderm mesoderm endoderm

Growth in the Uterus amnion surrounds protects Amniotic fluid placenta __________ - __________ the embryo and__________ the embryo, holds in a fluid called ____________________ __________ - organ responsible for the __________, by __________, of __________ and __________ from the mother’s __________ to the fetus. __________ from the fetus __________ to the mother’s blood through the __________. The mother’s and fetus’ blood ____________________ ____________________ - attaches the __________ to the __________. Contains ____________________ that connect the embryo’s __________ system to the __________ of the placenta passage diffusion nutrients oxygen blood wastes diffuse placenta Never mix Umbilical chord embryo placenta Blood vessels circulatory capillaries

Reproductive Technology reproduction insects Reproductive technology has greatly changed the way we can deal with problems involving _______________ of humans as well as other plants and organisms. Agriculture scientists have produced plants resistant to __________, _______________, or even __________ Resistant plants can be __________ to produce more resistant crops _________________________ - used to reproduce farm animals that exhibit genetic advantages ____________________ - enables infertile women to become pregnant ____________________ - eggs are extracted from an infertile woman and __________ with sperm in a laboratory dish. The ____________________ are implanted into the woman’s uterus, and a _______________pregnancy may result. _______________ and ____________________ allow doctors to view __________, __________, and other reproductive structures Weed killers frost cloned Artificial insemination Hormone therapy Invitro fertilization fertilized Fertilized eggs successful ultrasound Miniature cameras ovaries oviducts

Invitro Fertilization

Chromosomal abnormalities Biochemical deficiencies Amniocentesis _______________ - procedure to extract fluid from around the developing fetus Doctors analyze the cells in the __________ fluid _________________________ and ____________________ can be detected that may threaten the health of the developing fetus amniocentesis amniotic Chromosomal abnormalities Biochemical deficiencies

Dangers that face a Fetus placenta The __________ prevents most infections that make the mother ill from passing to the fetus __________ - passes through the tissues of the mother and may affect the fetus __________ - damages the dividing __________ of the fetus _________________________ - found within the mother can enter the fetus ____________________ by the mother affects development in the fetus and may produce underweight babies Exposure to __________ or __________ are also harmful to the fetus Use of __________, __________, LSD, and __________ during pregnancy can cause serious results ____________________ and ____________________ can result from __________ and __________ passing from the mother’s blood to the fetus radiation X-rays cells Infectious microorganisms Cigarette smoking toxins chemicals heroine cocaine alcohol addiction Mental retardation drugs alcohol

Fertilization & Development in Other Organisms Fish and Amphibians Fertilization is __________ Females lay __________ numbers of eggs in the water This ensures the __________ of the species Males will __________ sperm over the eggs in the water to fertilize them external large survival deposit Advantages Disadvantages Moist surroundings Egg and sperm may not __________ Eggs may be __________ Changes in _________________ may destroy the eggs and sperm (__________, ________________, and _________________________ meet eaten environment water temperature Oxygen concentration

Fertilization & Development in Other Organisms Birds and Reptiles In birds and reptiles, fertilization is __________, within the female’s reproductive tract __________ produce a __________ shell around the egg and ____________ is external – outside the female’s body __________ produce a __________ shell around the egg and ____________ is external – outside the female’s body internal reptiles leathery development birds hard development

Fertilization & Development in Other Organisms Non-placental Mammals – Egg Laying Mammals ____________________ - have __________ fertilization Lay ____________________ eggs When __________, the young are nourished by the mother’s ____________________ Examples of egg laying mammals are: ____________________ Egg laying mammals internal Soft shell hatched Mammory glands Duck billed platypus Spiny anteater

Fertilization & Development in Other Organisms Non-placental Mammals – Marsupials internal ____________________ - have __________ fertilization ____________________ - begin development __________ the female The __________ of the egg is used for __________ A tiny __________ leaves the mother’s body and crawls across the mother’s fur into a __________ Once in the __________, the __________ will receive nourishment from the mother’s ____________________ Examples of marsupials are: ____________________, ____________________, ____________________, and ____________________, Fertilized egg inside yolk food embryo pouch pouch embryo Mammary glands kangaroo koalas wombats possums