AP Bio Exam 3 Flashcards
Heredity
The transmission of traits from one generation to the next
Variation
A different combinations in which genetic traits are passed down
Genetics
Scientific study of heredity and inherited variation
Genes
Hereditary units of coded information
Where is the genetic program encoded in
DNA (polymer of four different nucleotides)
Gametes
Reproductive Cells
Somatic Cells
All cells of the body except gametes
How many chromosomes do humans have
46
Locus
Location of a specific gene’s location along the length of a chromosome
Describe asexual reproduction
A single individual passes copies of all of its genes to its offspring without the fusion of gametes. Creates an exact clone.
Describe sexual reproduction
Two parents give rise to offspring that have unique combos of genes.
What happens to chromosomes during mitosis
They condense, enough to be visible. Thus, we can distinguish them by size, the position of the centromeres, and the pattern of colored bands
The 46 chromosomes of the human body have
Two chromosomes of each 23 types
Karyotype
An ordered display of chromosomes
What do homologous pairs share?
Same length, centromere position, and staining pattern
(Except for X, Y, chromosomes!)
What is an interesting notice about the X, and Y chromosome?
The X is much longer
Sex Chromosomes
The X and Y chromosomes that determine your sex
Autosomes
All other chromosomes outside of sex chromosomes
The number of chromosomes represented by a single set is denoted by the symbol
n
Diploid cell
Any cell with two chromosome sets (2n)
Diploid number for humans
46 = 2n
What do gametes contain?
Haploid cells (n = 23)
Diploid v. Haploid Cells
Haploid: Single set of chromosomes
Diploid: double set of chromosomes
Human Life Cycle
Two haploids (Sperm, n) and (Egg, n) join to make a diploid zygote (2n)