Prenataldevelopment

Question 1

Gestation is the period between ____ and ____.

Answer 1

Gestation is the period between conception and birth.

Question 2

How is gestational age calculated?

Answer 2

Calculated from the first day of the mothers last menstrual cycle to the current date

Question 3

During week two, what event(s) occur?

Answer 3

Egg is released from the ovary.

Question 4

During week three, what event(s) occur?

Answer 4

• Sperm and egg meet in fallopian tube
• Combined sperm/egg-zygote
• Zygote = 43 chromosomes — 23 from each parent.
• Begins dividing to form a ball of cells-blastocyst
• Blastocyst-inne group of cells with an outer shell.
• Inner group of cells-embryopblast - becomes an embryo
• Trophoblast - Outer group of cells become the placenta

Question 5

Define: Mendelian Trait

Answer 5

Dominant/Recessive

Examples: Cystic Fibrosis, Marfan Syndrome, Huntington’s diesease

Question 6

Define: Polygenic Trait

Answer 6

Controlled by two or more genes at different locations on different chromosomes.

Examples: Hair color, eye color, skin color, height

Question 7

Define: Epigenetic Expression

Answer 7

External modification to DNA that turn genes off/on.

Does NOT change the DNA sequence.

Examples: Food, nutrition, thermoplastics, etc.

Question 8

Monozygotic twins are ____ twins

Answer 8

Identical

Question 9

Dizygotic twins are ____ twins

Answer 9

Fraternal

Question 10

During week 4 of pregnancy what physiological actions are occurring?

Answer 10

• Blastocyst reaches uterus
• Implants into uterine wall (endometrium)
• Lining of uterus thick with blood
• nourishment from mother’s blood
• Human Chronic Gonadotropin (hCG) production begins.

Question 11

Explain an Ectopic Pregnancy.

Answer 11

The sperm is able to plant in the fallopian tubes but does so in the wrong direction.

Question 12

During week 5 of pregnancy what physiological actions are occurring?

Answer 12

• HCG produced by blastocysts increase
• Signals ovaries to stop releasing eggs and produce more estrogen and progesterone.
• Cells multiply and start to take on specific functions.
• Blood cells, kindey cells, and nerve cells develop.
• Brain, spinal cord, and heart begin to develop.
• Gastroinstestinal tract starts to form.
• Embryo grows rapidly.
• External features begin to from.