Distinguish between the following pairs of terms:
a) somatic cell and gamete
b) autosome and sex chromosome
A) Somatic cell: Two chromosomes of each type, known as homologous chromosomes.
Gamete: Egg and sperm
B) Autosome: Chromosomes other than the sex chromosomes.
Sex chromosome: Determine the sex of a person: XX= Female, XY= Male
Explain how haploid and diploid cells differ from each other. State which cells in the human body are diploid cells differ from each other. State which cells in the human body are diploid and which are haploid.
Haploid cells: Gametes, egg and sperm (contain a single set of chromosomes).
Diploid cells: Somatic cells (one from each parent).
List the phases of meiosis I and meiosis II and describe the events characteristic of each phase.
Meiosis I
- Prophase I: Replicated homologous chromosomes.
-Metaphase I: Chromosomes line up on the metaphase plate (horizontally).
-Anaphase I: Chromosomes separate on opposite poles of the cell.
-Telophase I/Cytokinesis: The cleavage furrow forms and th
Describe the process of synapsis during prophase I. What happens during this?
The pairing of two homologous chromosomes that occurs during meiosis. The genetic material is rearranged by crossing over between nonsister chromatids.
Describe two events that occur during Meiosis I but not during Mitosis.
In metaphase I, the metaphase plate is lined horizontally whereas the mitosis has their plate vertically.
allele
One of two or more forms of a gene.
asexual reproduction
A single parent passes copies of all its genes to its offspring.
autosome
Chromosomes other than the sex chromosomes.
chiasma
Crossovers are visible later in the stage, where sister chromatid cohesion holds the original sister chromatids together.
clone
A group of genetically identical offspring.
crossing over
The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis.
diploid cell
Somatic cells (one from each parent).
haploid cell
Gametes, egg and sperm (contain a single set of chromosomes).
homologous chromosomes
Two chromosomes of each type, from each parent.
meiosis I
Separation of homologous chromosomes
meiosis II
Separation of sister chromatids
recombinant
In prophase I, homologous chromosomes segments of nonsister chromatids are exchanged by crossing over, with genetic combinations of maternal and paternal genes on the same chromosome.
sex chromosome
Determine the sex of a person: XX= Female, XY= Male
sexual reproduction
An individual receives a unique combination of genes inherited from two parents.
somatic cell
Two chromosomes of each type, known as homologous chromosomes.
synapsis
The pairing of two homologous chromosomes that occurs during meiosis.
zygote
Contains both paternal and maternal sets of chromosomes (fusion of egg and sperm).