Genetics & Heredity

Heredity or Environment?  Color of hair  Color of eyes  Color of Skin  General health  Personality traits  Strength of eyesight  Physical strength  IQ  Height  Relationship with family  Relationship with friends  Level of education  Sex / Gender  Body Type  Weight  Religious involvement  Birth Defects  Blood Type

Study Guide T/F Questions  1. _______ The passing on of traits from parent to child is called heredity. Environmental influences are the surroundings that we are placed in.  READ The Scenario: Sammy has brown eyes and is five years old. She attends a neighborhood preschool every day. Her teachers have fallen in love with her witty personality and honey-colored hair. She is very intelligent and does well with the tasks assigned to her. Sammy’s parents are divorced and she misses her father very much. Sammy has juvenile arthritis and must see the doctor often. At her last doctor’s visit, the doctor reminded Sammy’s mom that diabetes has run in her family for several generations and that Sammy should be watched closely for any early symptoms of diabetes. Sammy’s growth chart shows that she will probably be small for her age.  List the Heredity Influences in the above scenario:  List the Environmental Influences in the above scenario: T

 2. _______ Genes carry inherited traits that are passed on from generations to generations. Hundreds of thousands of genes, which make up the traits of human beings, are carried on every chromosome. T

 3. ________Heredity influences such personal aspects as eye color, personality, and F food preference.

 4. _______ Dominant genes are stronger genes and recessive genes are weaker. T

Dominant vs. Recessive a. widow’s peak a. Continuous hairline b. Unattached earlobe a. Attached earlobe c. Short fingers a. Long fingers d. Freckles a. Lack of freckles

 5. _______ In the formation of a new individual where the genes are both recessive and dominant, the dominant will overpower. T  RECESSIVE Blonde hair Red hair Blue Eyes Widows peak Attached earlobes Can’t roll tongue Interlock hands and right thumb on top No hitchhiker’s thumb  DOMINANT Brown hair Other Color hair Brown eyes Straight hair line Free Earlobes Roll Tongue Second finger shorter then the 4 th Hitchhiker’s thumb

6. _______ It is probable that a dominant brown-eyed mother and a recessive blue-eyed father will have a brown-eyed child. Determine the chances of passing on a genetic trait in the following situation:  The wife is blue-eyed and carries genes for blue eyes on both of the chromosome pairs. The husband is brown eyed and carries a gene for brown eyes on one of the pairs and a gene for blue eyes on he other one of the pairs. Complete the following grid to determine the chances for each of their children to be born with blue or brown eyes. B = dominant brown gene b = recessive blue gene  There is a __________2___________ in four chance that the child will have brown eyes and carry a gene for blue eyes.  There is a __________2___________ in four chance that the child will have blue eyes and carry genes for only blue eyes. Wife b Husband B Husband b T Bb bb Bb bb

 7. _______ It is probable that a child can have recessive light colored hair even though both of his parents have dominant dark colored hair. Red Hair and blue –green eyes T

Recessive (weaker) genes will not produce the characteristic unless transmitted by both parents.

 8. _______ The female sex cell is the ovum with chromosomes and the male sex cell is the sperm with chromosomes. F XX XY XY XX

 9. _______ Each sperm cell and ovum cell carries 23 chromosomes and when the ovum is fertilized, the sex cell equals 46.  10. _______ 50% of the chromosomes come from the father, but he determines the sex of the child. XY Boy or XX Girl? F T new eyes Chromosomes.

 11. _______ is the union of an ovum and a sperm or the beginning of pregnancy. is the union of an ovum and a sperm or the beginning of pregnancy. F TwitterpationConception

MULTIPLE BIRTHS

 12. _______ Fraternal non-identical multiple births that come from two different eggs will look. F identical like siblings.

FRATERNAL TWINS Form when two eggs are released at the same time and each is fertilized. They grow side by side in the uterus. Because they are the result of two different ovum and sperm they are no more alike in terms of heredity than other siblings. They may be of opposite sexes.

 13. _______ Identical multiple births that come from one fertilized egg F can be different sexes. will be the same sex.

IDENTICAL TWINS A fertilized egg starts growing by dividing into two cells. These cells continue to divide. Sometimes, the cell mass splits in half soon after fertilization. Each cell mass grows into a separate embryo. They are always the same sex, and have very similar characteristics because they began as one zygote.

TRIPLETS * Triplets can occur through several combinations. Three separate ovum could be released and fertilized. * Two ovum could be released, fertilized and then one ovum splits into separate embryo, resulting in a set of identical twins and one fraternal twin. * One ovum could split into two parts resulting in identical triplets

14. _______ 14. _______ are when the ovum splits apart but the separation is not complete. are when the ovum splits apart but the separation is not complete. F Double jointed twins Conjoined twins

CONJOINED TWINS Conjoined twins result when a fertilized ovum begins to split into two parts, but does not fully complete the process. The babies are joined at whatever location does not complete the splitting process.

Beanie Baby’s First Portrait Complete the Genetic Gamble 1. Roll for your Baby’s gender 2. Roll for all characteristics Head / Evens = Dominant or Capital Tails / Odds = Recessive or Lowercase - Person #1 Rolls a _______ = recessive or dominant - Person #2 Rolls a _______ = recessive or dominant - Based on the results of the 2 rolls, your baby has_____________ characteristics.