Chapter 13: Flashcards
What is heredity?
The transmission of traits from one generation to the next
What is the difference between inheritance and heredity?
nothing
What are the units of heredity?
genes
What is DNA?
A polymer of 4 nucleotides
A certain combo of nucleotides = ?
A gene
What are the vehicles for fertilization?
Gametes
T or F? All species have the same # of chromosomes?
F
What is a locus
A genes specific location on the chromosome
What is a sexual reproduction?
a single individual produces two genetically identical offspring w/o fusion of gametes
What is a clone
a group of genetically identical individuals
What is sexual reproduction?
to parents give rise to offspring with mixed DNA from both parents
How many chromosomes does a somatic cell have?
46
How many chromosomes does a gamete have?
23
If one were to take images of all chromosomes and arrange them in pairs by length this would be called a _____?
karyotype
What are homologous chromosomes in meiosis?
corresponding sets of sister chromatids
How may pairs of autosomes does a somatic cell have?
22
What is an autosome?
not sex chromosomes
What is a diploid cell?
A cell with two full sets of chromosomes
What is a haploid cell?
A cell with one chromosome set
What do you call a chromosome that has been duplicated?
2 sister chromatids
What is fertilization?
The union of gametes
What is a fertilized egg referred to as?
A zygote
Is a zygote haploid or diploid?
diploid
Meiosis is responsable for the creation of what type of cells?
gametes
What are the cells that initially start the process of meiosis to produce gametes?
germ cells
What is alternation of generation
includes both diploid and haploid stages that are multicellular
What organism uses alternation of generations?
Plants and some algae
Only diploid cells can divide by mitosis. T or F?
F
Only diploid cell can divide by meiosis. T or F?
T
Meiosis results in how many daughter cells?
4
What is the end product of meiosis I of meiosis?
two haploid cells with duplicated chromosomes
What is the end products of meiosis II?
Haploid cells with unduplicated chromosomes
Sister chromosomes make up one ________ _________
duplicated chromosomes
What are the differences between homologous chromosomes?
one is paternal and one is maternal
Homologous pairs differentiate depending on the alleles at certain loci. T or F?
T
What is the basic goal of meiosis I?
to separate homologous chromosomes
what are the phases of meiosis I?
Prophase I
Metaphase I
Anaphase I
Telophase and Cytokinesis I
What stage does crossing over occur?
Prophase I
What happens in prophase I?
Duplicated homologous chromosomes pair up and exchange segments of their DNA
What is the chiasmata?
the point where crossing over occurs
What happens in metaphase I?
chromosomes line up by homologous pairs
What happens in anaphase I?
the two homologous chromosomes of each pair separate
What happens in telophase I and cytokinesis?
two haploid cells form; each chromosome still consists of two sister chromatids
T or F? During metaphase a kinetochore molecule attaches microtubules to both chromatids of one homolog
T
In anaphase I are the sister chromatids still attached?
yes
T or F? Chromosome duplication occurs in-between meiosis I and meiosis II.
F
In what phase(s) do spindle apparatus form?
Prophase I and II
How are chromosomes or sister chromatids moved to metaphase plate?
via microtubules
What happens in metaphase II?
Sister chromatids line up at metaphase plate
What happens in Anaphase II?
Sister chromatids are pulled apart after an enzyme breaks down the cohesion
In what stage do nucleoli form in meiosis?
telophase II
If one were to start meiosis with 4 chromosomes in one cell, how many chromosomes would be in each daughter cell and how many cells would there be?
In total you would have 8 chromosomes
In each haploid cell you would have 2
Crossing over occurs between what two chromatids?
non sister paternal and maternal
What is the synaptonemal complex?
A zipper like structure that hols the homologs together
What is synapsis?
DNA breaks close up and attached to corresponding segment of non sister chromatid (crossing over)
IN the cell cycle where is independent assortment seen?
Metaphase I
