Unit 5 Part 1 Flashcards
What’s genetics
The study of heredity and heredity variation
What’s heredity
The transmission of traits form one generation to the next
What are genes
Segments of dna that code for basic units of heredity
Asexual reproduction individuals
1 individual
Asexual gametes?
No fusion of gametes
Asexual makes:
clones of the parent, variation only happens through mutations
Sexual reproduction individuals
2 individuals
Sexual: offspring are
Unique and genetically varied
Homologous chromosomes are?
Pair of chromosomes that are same size same length same centromere position
What’s a karyotype
display of chromosome pairs ordered by size and length
Diploid =
Two complete sets of each chromosome
Haploid =
One set of chromosomes
What’s a life cycle
Sequence of stages in the reproductive history of an organism from conception to its own reproduction
What’s meiosis
Process that creates 4 haploid gamete cells
Meiosis I: interphase
cell goes through G1, S, and G2
Meiosis I: prophase
Synapsis: homologous chromosomes pair up and physically connect to each other forming a tetrad
Crossing over (recombination) occurs at the chiasmata and DNA is exchanged between the homologous pairs
Metaphase I
Independent orientation: tetrads line up at the metaphase plate
Anaphase I
Pairs of homologous chromosomes separate, sister chromosomes are still attached
Telophase I and Cytokenesis
Nuclei and cytoplasm divide, there is now a haploid set of chromosomes in each daughter cell
Prophase II
No crossing over, spindle forms
Metaphase II
Chromosomes line up at metaphase plate, because of crossing over in meiosis I chromatids are unique
Anaphase II
sister chromatids separate and move towards opposite poles