Lab 19 Reproductive System

Activity 1: Male Reproductive Anatomy

1.      Obtain torso and reproductive models, stickers and felt pen.
2.      Write the organs and structures that you should be able to identify on the stickers
        Testicle, Epididymis, Spermatocord, vas Defrens (Ductus Defrens), Scrotum, Prostate Gland, Seminal Vesicles, Penis, Glans Penis, Corpus Cavernosum, Corpus         Spongiosum
3.      Take turns within your group to label the structures. As you label indicate the function of the organ or structure for the excretory system

4.      Have your instructor check your labeling before moving to Activity 2.

Activity 2: Female Reproductive Anatomy

1.      Obtain torso and reproductive models, stickers and felt pen.
2.      Write the organs and structures that you should be able to identify on the stickers
        Ovary, Fallopian (Uterine) Tube, Uterus, Cervix, Vagina, Mammary Gland, Lactiferous Sinus, Nipple, Areola (and glands)

3.      Take turns within your group to label the structures. As you label indicate the function of the organ or structure for the excretory system

4.      Have your instructor check your labeling before cleaning up your area.

Activity 3: Heredity and Reproduction

The formation of gametes occurs via the process of meiosis, where at the end of the process cells that are formed will contain ½ the allotment of chromosomes as the original cells in the process. So that when they interact and form the zygote, the cell will have the correct allotment of chromosomes.  The key steps during the formation of gametes lead to variability of the genes (and physical characteristics) seen in offspring, relative to parents.  
The stages of gametogenesis that lead to this genetic diversity are based on Mendel’s laws of inheritance.  The two that are very important remember are the laws of independent assortment and the segregation of the alleles (genes).  Which indicates that genes can be “assigned” independent of all other genes to any of the gametes and can be exchanged between chromosomes independent of any other gene on the chromosome during both the formation of the gametes. Not only will the genes be “assigned” independently during the process of forming the gamete, but they can also assemble in the zygote independently, too.  We can examine the likelihood of genes being passed from the parent to the offspring through the development of the Punnett Square.
The Punnett Square is the process by which we indicate the various possible genes that each parent can contribute for given physical traits and then the possible combinations that each possible contribution can be seen in the offspring.  All these chances of how genes separate and then coalesce in the zygote gives us distinct probability charts that we can use for predicting what the child might express.  In examining these probabilities there are two things that we always must remember. First, the chance of getting any single gene from a parent is random (a flip of the coin). Second, the chance of having the gene being expressed is based on the concept of dominance. Where the child has equal chance of getting any copy of any gene that the parent has but will express those genes based the resulting combination of genes from both parents. In which, dominant traits will always have some degree of being expressed (depending on being fully dominant or having a co-dominance or an incomplete dominance expression) while the recessive traits are only expressed when the person has two identical recessive genes (homozygous recessive).
To examine this concept, we will be exploring the genetic inheritance and probability of expressing traits for one’s facial features.

1.      Determine the genotype for your facial features

2.      Create a table of phenotypes and genotypes that are possible for each parent in your pairing.

a.      Use yourself as 1 parent and your lab partner as the other parent.

3.      Determine the Genotype for the child:

a.      To determine the gender of the child, have the father will flip the coin

i.     HEADS=Girl, TAILS=Boy

Think about Question: WHY THE MALE IS THE ONLY PARENT TO FLIP A COIN TO DETERMINE THE SEX OF THE CHILD.
Think about question: EXPLAIN WHAT THE COIN REPRESENTS

b.      If the parent is heterozygous for a trait, then that person will have to flip a coin to determine which allele is passed to the child.

i.     Designate HEADS=Dominant and TAILS=Recessive
ii.     If both parents are heterozygous, each will flip the coin (simultaneously) for each of the trait that is heterozygous on the chart. 

1.      Results of the allele assortment is as follows:

a.       Two tails indicate homozygous recessive trait expressed.
b.      One head and One tail indicate heterozygous trait expressed
c.       Two heads indicate homozygous dominant trait expressed.
d.      For Polygenic traits flip the coin each time for the individual genes within the polygenetic trait.

c.      If the parent is homozygous then simply write the only allele that can be passed to the child in the designated area
d.      Record the outcome of genotype for the child based on the results of the coin flips

4.      Record the phenotype that the child

a.      Based on results of the combination of alleles, compare the child’s genotype with the indicate characteristic for facial features
b.      Write the phenotype that is expressed based on the results of the genotype combination.

5.      To the best of your ability, draw a representation of the outcome of all flips to create a drawing of the child that results from the two parents in this lab.