Bio 111 UPDATED ACTUAL Questions
and CORRECT Answers
Asexual (vegetative) reproduction - CORRECT ANSWER Example, a new plant grows
out of the root or a shoot from an existing plant.
Produces only genetically identical offspring since all divisions are by mitosis.
Offspring called clones meaning that each is an exact copy of the original organism
This method of reproduction is rapid and effective allowing the spread of an organism
Since the offspring are identical, there is no mechanism for introducing diversity
Sexual reproduction - CORRECT ANSWER Formation of new individual by a
combination of two haploid sex cells (gametes).
Fertilization- combination of genetic information from two separate cells that have one half the
original genetic information
Gametes for fertilization usually come from separate parents
Female- produces an egg
Male produces sperm
Both gametes are haploid, with a single set of chromosomes
The new individual is called a zygote, with two sets of chromosomes (diploid).
Meiosis is a process to convert a diploid cell to a haploid gamete, and cause a change in the
genetic information to increase diversity in the offspring.
Chromosomes in a Diploid Cell - CORRECT ANSWER Diploid set for humans; 2n = 46
Autosomes; homologous chromosomes, one from each parent (humans = 22 sets of 2)
Sex chromosomes (humans have 1 set of 2)
Female-sex chromosomes are homologous (XX)
Male-sex chromosomes are non-homologous (XY)
Karyotype - CORRECT ANSWER A pictorial display of metaphase chromosomes from a
mitotic cell
, Homologous chromosomes- pairs
Ploidy: Number of sets of chromosomes in a cell - CORRECT ANSWER Haploid (n)--
one set chromosomes
Diploid (2n)-- two sets chromosomes
Most plant and animal adults are diploid (2n)
Eggs and sperm are haploid (n)
What is meiosis I? - CORRECT ANSWER In meiosis I, chromosomes in a diploid cell
resegregate, producing four haploid daughter cells. It is this step in meiosis that generates genetic
diversity
Prophase I - CORRECT ANSWER DNA replication precedes the start of meiosis I.
During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis.
The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic
recombination becomes apparent. Chromosomal condensation allows these to be viewed in the
microscope. Note that the bivalent has two chromosomes and four chromatids, with one
chromosome coming from each parent.
Prometaphase I - CORRECT ANSWER The nuclear membrane disappears. One
kinetochore forms per chromosome rather than one per chromatid, and the chromosomes
attached to spindle fibers begin to move.
Metaphase I - CORRECT ANSWER Bivalents, each composed of two chromosomes (four
chromatids) align at the metaphase plate. The orientation is random, with either parental
homologue on a side. This means that there is a 50-50 chance for the daughter cells to get either
the mother's or father's homologue for each chromosome.
Anaphase I - CORRECT ANSWER Chiasmata separate. Chromosomes, each with two
chromatids, move to separate poles. Each of the daughter cells is now haploid (23
chromosomes), but each chromosome has two chromatids.
and CORRECT Answers
Asexual (vegetative) reproduction - CORRECT ANSWER Example, a new plant grows
out of the root or a shoot from an existing plant.
Produces only genetically identical offspring since all divisions are by mitosis.
Offspring called clones meaning that each is an exact copy of the original organism
This method of reproduction is rapid and effective allowing the spread of an organism
Since the offspring are identical, there is no mechanism for introducing diversity
Sexual reproduction - CORRECT ANSWER Formation of new individual by a
combination of two haploid sex cells (gametes).
Fertilization- combination of genetic information from two separate cells that have one half the
original genetic information
Gametes for fertilization usually come from separate parents
Female- produces an egg
Male produces sperm
Both gametes are haploid, with a single set of chromosomes
The new individual is called a zygote, with two sets of chromosomes (diploid).
Meiosis is a process to convert a diploid cell to a haploid gamete, and cause a change in the
genetic information to increase diversity in the offspring.
Chromosomes in a Diploid Cell - CORRECT ANSWER Diploid set for humans; 2n = 46
Autosomes; homologous chromosomes, one from each parent (humans = 22 sets of 2)
Sex chromosomes (humans have 1 set of 2)
Female-sex chromosomes are homologous (XX)
Male-sex chromosomes are non-homologous (XY)
Karyotype - CORRECT ANSWER A pictorial display of metaphase chromosomes from a
mitotic cell
, Homologous chromosomes- pairs
Ploidy: Number of sets of chromosomes in a cell - CORRECT ANSWER Haploid (n)--
one set chromosomes
Diploid (2n)-- two sets chromosomes
Most plant and animal adults are diploid (2n)
Eggs and sperm are haploid (n)
What is meiosis I? - CORRECT ANSWER In meiosis I, chromosomes in a diploid cell
resegregate, producing four haploid daughter cells. It is this step in meiosis that generates genetic
diversity
Prophase I - CORRECT ANSWER DNA replication precedes the start of meiosis I.
During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis.
The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic
recombination becomes apparent. Chromosomal condensation allows these to be viewed in the
microscope. Note that the bivalent has two chromosomes and four chromatids, with one
chromosome coming from each parent.
Prometaphase I - CORRECT ANSWER The nuclear membrane disappears. One
kinetochore forms per chromosome rather than one per chromatid, and the chromosomes
attached to spindle fibers begin to move.
Metaphase I - CORRECT ANSWER Bivalents, each composed of two chromosomes (four
chromatids) align at the metaphase plate. The orientation is random, with either parental
homologue on a side. This means that there is a 50-50 chance for the daughter cells to get either
the mother's or father's homologue for each chromosome.
Anaphase I - CORRECT ANSWER Chiasmata separate. Chromosomes, each with two
chromatids, move to separate poles. Each of the daughter cells is now haploid (23
chromosomes), but each chromosome has two chromatids.
