Chapter 2 Flashcards
(23 cards)
Sex linked genes
A gene located on a sex chromosome
Usually the X chromosome
Gametes
Meiosis forms egg and sperm sex cells
Genotype
Persons genetic material
Inside the body
Phenotype
Physical characteristics of a person
Outside the body. Based on the genotype
Dominant
Overriding the other gene
Recessive
Shows itself only if both genes are recessive. Dominant always over rides
Down syndrome
Extra copy of the chromosome 21
In vitro fertilization
Process of fertilization
When the egg and sperm are combined outside the body in vitro
Evolutionary Perspective
What matters is the individual lives long enough to reproduce and pass on characteristics.
Selection operates during the 1st half of life
When age increases the evolutionary selection decreases and
Turner
Missing X chromosome in female
Amniocentesis
Prenatal procedure that takes a sample of the Amniotic fluid and is tested for chromosomal or metabolic disorders
15-18th week in pregnancy
Ultrasound sonography
Prenatal procedure high-frequency sound waves are directed into the abdomen echo sound transforms into visual representation of the fetus is inner structure this detects abnormalities in the fetus
Chorionic Villus Sampling (CVS)
10-12th week in pregnancy
Prenatal procedure that removes a small sample of the placenta.
Detects genetic defects and chromosomal abnormality
XXY
Extra Y chromosome for male
Klinefelter
Males have an extra X chromosome making them XXY instead of the normal XY
Polygenetic Inheritance
Occurred when 1 characteristic is controlled by 2 or more genes.
Height, skin color, eye color
Fraternal Twins
2 eggs are fertilized by different sperm creating 2 ZYGOTES that are no more similar than ordinary siblings
DIZYOTIC — 2 eggs 2 sperm
Identical twins
Developed from 1 ZYGOTE that splits into 2 genetically identical twins.
MONOZYGOTIC 1 egg 1 sperm
Mitosis
The cells nucleus duplicated itself
splits once and forms 2 new cells
Each containing the SAME DNA as the parent cell in the same 23 pairs of chromosomes
Meiosis
Form of cell division
Splits twice and forms 4 cells
Each has HALF the generic material as the parent cell
DNA
A complex molecule that has a double helix and contains genetic material
Genes
Short segments of DNA helps reproduce and assemble proteins
Genes direct cells to reproduce themselves
Proteins are the building blocks of cells
Chromosomes
The nucleus of each human cell contains chromosomes
Threadline structures made up of DNA.
Comes in 23 pairs
