Biology 101 Exam 2 UW Madison UPDATED ACTUAL Questions And Correct
Answers
C
Terms in this set (136)
# of chromosomes in gametes vs zygotes: Gametes: 23 chromosomes
Zygotes: 46 chromosomes
Why is the timing of meiosis and fertilization important in Meiosis has to occur before fertilization because in meiosis, gametes are formed
the human life cycle? and in fertilization, the gametes come together and reproduce.
What is the difference between prophase I and prophase Prophase I of meiosis:
of mitosis? -Synapsis occurs- pairing of homologous chromosomes.
-Crossing over occurs- exchange of genetic material b/w maternal and paternal
chromatids.
Prophase of mitosis does not have synapsis or crossing over.
What is the process of pairing homologous Maternal chromosomes and paternal chromosomes pair in meiosis. Genes come
chromosomes and consequences of doing so? in pairs that separate from one another in formation of gametes. This could result
in different traits being represented in offspring.
What is the difference between metaphase I and Metaphase I of meiosis:
metaphase of mitosis? -homologous pairs of chromosomes line up on metaphase plate (random
alignment: independent assortment).
Metaphase of mitosis:
-Chromosomes line up on metaphase plate
What is the difference between anaphase I and anaphase Anaphase I of meiosis:
of mitosis? -synaptonemal complex degrades -> homologous chromosomes separate and
move to opposite poles of cell.
-sister chromatids stay attached
Anaphase of mitosis:
-Cohesins degrade
-sister chromatids separate to opposite ends of cell
, What are key events in Telophase I of meiosis? Each half of the cell has complete 1n set of replicated chromosomes, each
chromosome consisting of two sister chromatids.
Interkinesis -> both haploid cells enter meiosis II
What are the events of meiosis II? Prophase II
Metaphase II
Anaphase II: chromatids separate in this phase and move to opposite poles of
cells
Telophase and Cytokinesis: four haploid daughter cells, nuclei reform and
chromosomes decondense.
In what ways does meiosis increase genetic variability 1) Mutation
and why this is important? 2) Random alignment of chromosomes on metaphase I plate can produce 2^23
different gametes.
3) Crossing over
4) Fertilization
Important to know because it lets us determine chances of forming certain traits
in offspring.
What is nondisjunction? An error in cell division that causes homologous chromosomes or sister
chromatids to move to the same side of the dividing cell. Resulting in n+1 gamete
extra chromosomes or n-1 gamete missing chromosomes.
Happens on gene 21 and can lead to down syndrome
Why does advanced material aging increase risk of non- When the cells are going through meiosis there is a chance they miss the M1
disjunction event to occur? checkpoint and this could result in homologous chromosomes or sister
chromatids not separating from the other.
What is the difference between blending theory of Blending theory:
inheritance and particulate theory of inheritance? -Theory that explains the genetic material of parents mixes similar to the colors
yellow and blue making green.
Particulate theory:
-Parents pass on heritable genes that retain separate identities. One offspring
might be green, but the next might be blue and can pass on green gene or
yellow. Particulate genes!
Why are garden peas a good model organism to study -Short generation time
genetics? -Easily observable traits
-Ability to control matings/crossings
Monohybrid cross A cross between individuals that involves one pair of contrasting traits
Answers
C
Terms in this set (136)
# of chromosomes in gametes vs zygotes: Gametes: 23 chromosomes
Zygotes: 46 chromosomes
Why is the timing of meiosis and fertilization important in Meiosis has to occur before fertilization because in meiosis, gametes are formed
the human life cycle? and in fertilization, the gametes come together and reproduce.
What is the difference between prophase I and prophase Prophase I of meiosis:
of mitosis? -Synapsis occurs- pairing of homologous chromosomes.
-Crossing over occurs- exchange of genetic material b/w maternal and paternal
chromatids.
Prophase of mitosis does not have synapsis or crossing over.
What is the process of pairing homologous Maternal chromosomes and paternal chromosomes pair in meiosis. Genes come
chromosomes and consequences of doing so? in pairs that separate from one another in formation of gametes. This could result
in different traits being represented in offspring.
What is the difference between metaphase I and Metaphase I of meiosis:
metaphase of mitosis? -homologous pairs of chromosomes line up on metaphase plate (random
alignment: independent assortment).
Metaphase of mitosis:
-Chromosomes line up on metaphase plate
What is the difference between anaphase I and anaphase Anaphase I of meiosis:
of mitosis? -synaptonemal complex degrades -> homologous chromosomes separate and
move to opposite poles of cell.
-sister chromatids stay attached
Anaphase of mitosis:
-Cohesins degrade
-sister chromatids separate to opposite ends of cell
, What are key events in Telophase I of meiosis? Each half of the cell has complete 1n set of replicated chromosomes, each
chromosome consisting of two sister chromatids.
Interkinesis -> both haploid cells enter meiosis II
What are the events of meiosis II? Prophase II
Metaphase II
Anaphase II: chromatids separate in this phase and move to opposite poles of
cells
Telophase and Cytokinesis: four haploid daughter cells, nuclei reform and
chromosomes decondense.
In what ways does meiosis increase genetic variability 1) Mutation
and why this is important? 2) Random alignment of chromosomes on metaphase I plate can produce 2^23
different gametes.
3) Crossing over
4) Fertilization
Important to know because it lets us determine chances of forming certain traits
in offspring.
What is nondisjunction? An error in cell division that causes homologous chromosomes or sister
chromatids to move to the same side of the dividing cell. Resulting in n+1 gamete
extra chromosomes or n-1 gamete missing chromosomes.
Happens on gene 21 and can lead to down syndrome
Why does advanced material aging increase risk of non- When the cells are going through meiosis there is a chance they miss the M1
disjunction event to occur? checkpoint and this could result in homologous chromosomes or sister
chromatids not separating from the other.
What is the difference between blending theory of Blending theory:
inheritance and particulate theory of inheritance? -Theory that explains the genetic material of parents mixes similar to the colors
yellow and blue making green.
Particulate theory:
-Parents pass on heritable genes that retain separate identities. One offspring
might be green, but the next might be blue and can pass on green gene or
yellow. Particulate genes!
Why are garden peas a good model organism to study -Short generation time
genetics? -Easily observable traits
-Ability to control matings/crossings
Monohybrid cross A cross between individuals that involves one pair of contrasting traits
