Children The Early Years Chapter 4…Pregnancy 1 1

Pregnancy o Pregnancy is the process through which a new human prepares to enter the world. o Begins when the baby is created inside the mother’s body. o Lasts about 9 months. o Growth is rapid, it is affected by the genes of both parents 2

Conception fertilization_ bc

4 o Cell…The smallest unit of life that is able to reproduce itself. o Sperm…The male sex cell. o Ovum…The female sex cell or egg. o Zygote…The single cell formed at conception; also called a fertilized egg. 4

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6 o Conception…The union of the ovum and sperm cells. o Fallopian Tubes…Two hollow tubes that connect to the uterus and have fingerlike projections that reach toward each ovary. o Uterus...The organ in which the baby develops and is protected until birth. 6

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The Menstrual Cycle 8 Resources

10 “The average menstrual cycle is 28 to 32 days. Some women have longer or shorter cycles, so the exact timing of ovulation can vary. Here's an overview of a typical 28-day menstrual cycle”

 Day 1 Your cycle begins on the first day of blood flow.  Days 2-14 Follicular Phase The follicles on your ovary become active, and your cervical mucus starts to thin.  Day 14 Ovulation occurs mid-cycle, but can vary from between Day 11 and Day 21 of a woman's cycle. Rising estrogen levels trigger the LH surge, which causes the follicle to ovulate and release an egg. It's important to chart your basal body temperature and LH surge so you know when you ovulate. 11

o Days Luteal Phase o After releasing the egg, the follicle produces progesterone, which thickens the lining of the uterus for implantation. o Days 23 to 24 o Implantation of a fertilized egg can take place. At this point, hormones produced by pregnancy may be detected by a pregnancy test. o Days 25 to 28 o If pregnancy does not occur, your hormone levels begin to fall. The uterine lining sheds, resulting in your period. 12

There’s An App for That 13

Genetic Factors and the Unborn Baby o Genetic factors are the traits passed through the genes. o They are the blueprint for the baby. “the plans” o Inherited traits are passed to the baby at conception. o The code “plan” is stored in DNA. o The DNA is a chemical compound that is found in threadlike structures called chromosomes. 14

Chromosomes & Genes

o Chromosomes: rod- shaped structures, located in the nucleus of a cell, that carry genetic information. Each cell contains 46 chromosomes. o Genes: segments of a DNA molecule, located on a chromosome, that contain genetic information. Genes carry traits from parents to children.

Chromosomes o All living things have a certain number of chromosomes. o Each baby has 46=23MOM+23DAD o Meaning…each sperm carries 23 chromosomes from dad, and the ovum carries 23 from mom. 17

o Sex Determination is decided at the moment you conceive. One pair of the baby’s chromosomes, determines it’s sex. o These chromosomes are called “X” and “Y” chromosomes. o Females: 2 “X” chromosomes o Males: 1 “X” and 1 “Y” chromosomes

Eggs contain only “X” sex chromosomes. Sperm contain either “X” or “Y” chromosomes. The fathers contribution is the one that determines the sex of the fetus. pregnancy-girl-or-boy_ bc

Dominant & Recessive Traits

o In each chromosome, the genes occur in pairs. o One gene from mom, one from dad o The genes work together to determine the traits of the baby. o Moms and dads can pass traits that do not show up in them. o As a general rule…dominant traits ALWAYS show. 1 recessive trait will not usually show. 2 recessive traits usually show. 21

22 o Dominant Trait…Traits that always show in a person even if only one gene of the pair is inherited for that trait. o Recessive Traits…Traits that typically do not show in a person unless both genes for the trait are inherited. 22

Fun facts o Tallness is a dominant trait, shortness is a recessive trait 23

Multiple Pregnancy

Multiple Births o Sometimes 2 or more babies develop in the same pregnancy. o It’s called a multiple pregnancy. o Become more common because of fertility medications o The frequency of twins is about 1 in 35 births. o Three or more is 1 in 540 births. o The more babies…the higher the risks to the babies. 25

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Fraternal Twins vs Identical Twins o FRATERNAL: o There are 2 ova and 2 sperm=2 babies o Different genetic makeup o May or may not look alike, be the same gender o Each has their own chorion (membrane in the uterus) o IDENTICAL: o There is a single ova and a single sperm that SPLITS. o They do not know why this happens. o If it does not completely split the twins will be conjoined. o Identical twins look like but have different finger prints, footprints. o The usually share the same chrion, but may have separate chrions. 27

28 E70 Start at 2:00 end at 6

Germinal Stage 1 st Stage o Conception through 2 weeks o The zygote remains a single cell for about 1 day o On the 3 rd day, there are 32 cells o Cell divisions rapidly occurring o The Fertilized egg travels to the uterus and floats about o About 10 to 12 days after conception, the ball of cells embeds in the wall of the uterus o The chorion, Amnion, placenta, and umbilical cord beginning to form o This stage ends when the baby can receive nourishment from the mother 29

Embryonic Stage o The second stage of development is 2 weeks through 8 weeks – baby is called an embryo o Internal organs are developed – muy importante! o Tissue segments in the spinal column are forming o Limb buds appear o Ears and eyes begin to form o When this stage ends, they look like a human o Feeding through umbilical cord 30

Fetal Stage o Begins about 9 weeks until birth, the baby is called a fetus o Bone starts to replace cartilage o All parts of the body mature o Heartbeat can be heard o Movement can be felt about 4-5 months 31

Marshmallow Pyramid o Students will work together in groups. o Each group will design a freestanding pyramid. o 3 minutes o Items Needed o 4 large bags of marshmallow o toothpicks 32