Bio 111 lab TAMU exam
Asexual (vegetative) reproduction - 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 - 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 - 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 - ANSWER A pictorial display of metaphase chromosomes from a mitotic
cell
Homologous chromosomes- pairs
Ploidy: Number of sets of chromosomes in a cell - 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? - 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 - 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
Asexual (vegetative) reproduction - 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 - 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 - 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 - ANSWER A pictorial display of metaphase chromosomes from a mitotic
cell
Homologous chromosomes- pairs
Ploidy: Number of sets of chromosomes in a cell - 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? - 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 - 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
