Zygot Formation, Chromosomal Mutations, Embryo Formation Flashcards
Haploid+haploid=?
Diploid
n+n=?
2n
Zygote
Newly fertilized egg
Is the new zygote diploid or haploid?
Diploid
What are the two types of fertilization?
External fertilization
and
Internal fertilization
How does External fertilization occur?
Gametes join together outside the body of the female.
How does internal fertilization occur?
Gametes join together inside the female
There are_______ eggs in external fertilization.
Many
There are ______ eggs in internal fertilization.
Few
Describe the zygotes in external fertilization.
A large number are produced because they are more likely to be damaged outside
Describe the zygotes in internal fertilization.
Few because they are protected by the moist internal environment of the female
Examples of external fertilization
Fish, frogs
Examples of internal fertilization
Land animals
What is a chromosome mutation?
When changes occur which include variations in the number of individual chromosomes
What’s a trisomy?
3 copies of a single chromosome
What number chromosome has a trisomy in Down syndrome?
21st
What disease is 2n+1?
Down Syndrome
Down syndrome is found in ______ of every _____ births.
3, 1000
Name some characteristics of someone with down Syndrome.
Short stature, small, round head, mental disabilities with IQ seldom above 70, shorter life expectancy, more likely to have respiratory disease and heart defects
Frequency of babies with Down syndrome __________ as the age of the mother ________
Increases, increases
Describe Klinefelter Syndrome
Males with male genitalia but under developed testes that cannot produce sperm. Enlargement of breasts.
What is wrong with the chromosomes of a person with Klinefelter Syndrome?
They have a trisomy of the sex chromosome. They have a Y and 2 x’s instead of one.
Klinefelter Syndrome occurs in _____ of every _____ male births.
1, 500
What’s a monosomy?
Having one copy of a single chromosome
2n-1) (1 less than you need