Chapter 13 Meiosis And Sexual Life Cycle Flashcards
What do children inherit from their parents?
Just the DNA
Transformation of traits from one generation to the next
Heredity
Same trait but expressed differently. Ex. Eye color
Similar characteristics but not identical
Variation
…..
Genetics
Basic units of heredity
Made up of segments of DNA
Genes
Gametes
Sperm and egg
?The location for a specific trait?
Gene locus
Most DNA is packed into ______________
Chromosomes
Human somatic cells have _____ pairs of chromosomes
23
Homologous chromosome pairs are the same __________ and _____________
Length and centromere placement
Homologous chromosome pairs carry genes controlling the ________ inherited characters
Ex eye close
Same
Humans have _____ set of sex chromosomes and _____ pairs of autosome chromosomes
1, 22
2n is ….
Diploid -two sets
2n= 46 chromosomes total
n is …..
Haploid
Single set of chromosomes
n=23
Zygote…
One set of chromosomes from each parent
I cell
Each replicated chromosome consists of …..
Two identical sister chromatids
Meiosis starts with a _________ cell and ends with _________ cells
Diploid, haploid
Meiosis results in four daughter cells with only ____ as many chromosomes as the parent cell
Half
I’m meiosis 1 ____________ chromosomes separate and in meiosis 2 ____________ spectate
Homologous, sister
Two key differences from mitosis to meiosis
- homologous pairs form a bivalent or tetrad
- crossing over
Meiosis 1 and meiosis 2
Meiosis 1 (reductions division): homologous pair up and separate, resulting in two haploid daughter cells with replicated chromosomes
Meiosis 2 (equational division) sister chromatids separate
What is the spot on a chromosome called where crossing over happens?
Chiasma
Physical exchange between chromosomes prices of the crossing bivalent
Crossing over