Chapter 13- Meiosis Flashcards
Meiosis reduces the number of
chromosomes
A process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females.
meiosis
Sexual reproduction requires
meiosis
Cell division that reduces chromosome number by half
meiosis
A haploid reproductive cell.
Gametes (eggs and sperm) each contained two chromosomes
Any of the cells of a multicellular organism except those that are destined to form gametes (germ-line cells).
Somatic cells (non reproductive cells)
Normal mitotic cell: ___________
Cell after completion of meiosis: _________
2n (diploid)
n (haploid)
reproductive cells (n) _______________
nonreproductive cells (2n) _____________
Gametes
Somatic cells
An egg and a sperm (gametes), each containing half the complement of chromosomes found in other cells, fuse to produce a single cell called a
zygote
_________ can fuse and form a zygote (2n) in a process called_________
gametes
fertilization
The diploid (2n) cell resulting from the fusion of male and female gametes (fertilization).
zygote
The fusion of gametes to form a new cell is called
fertilization
Special reduction division, occurs during gamete formation, producing cells with half the normal number of chromosomes.
meiosis
Meiosis and fertilization together constitute a
cycle of reproduction
Two sets of chromosomes are present in the somatic cells of adult individuals, making them _______ cells, but only one set is present in the gametes, which are thus ________
diploid
haploid
Alternation of 2n and n via meiosis, fusion, and mitosis
sexual reproduction
Reproduction that involves alternation of meiosis and fertilization is called
sexual reproduction
Offspring inherit chromosomes from____________, You, for example, inherited ___ chromosomes from your mother (maternal homologue), and ___ from your father (paternal homologue).
two parents
23
23
In animals, the single diploid zygote undergoes________ to give rise to all of the cells in the adult body
mitosis
Somatic cells undergo mitosis to form genetically identical,_________________
diploid daughter cells
Both somatic cells and germline cells are __________
diploid
Germ-line cells can undergo _______ to produce ____________
meiosis
haploid gametes
The life cycles of all sexually reproducing organisms follow a pattern of alternation between
diploid and haploid chromosome numbers,
1) Single zygote cell will undergo _________ and eventually give rise to __________________
2) Cells that will eventually undergo meiosis to produce gametes are set aside from somatic cells early in the course of development
mitosis
all the cells of the body
germ-line cells
In animals, the zygote first undergoes mitosis to produce _______ cells. Then later in the life cycle, some of these ______ cells undergo meiosis to produce _______ gametes
diploid
diploid
haploid
Many types of algae, spend the majority of their life cycle in a _________ state.
haploid
in algae, the zygote undergoing meiosis produces ________ cells that then undergo mitosis.
haploid
During zygote development, cells that are set aside from the somatic cells and that will eventually undergo meiosis to produce gametes.
germ-line cells
Meiosis in a diploid organism consists of two rounds of division, called
Meiosis 1 and meiosis 2
The first round of cell division in meiosis; it is referred to as a “reduction division” because homologous chromosomes separate, and the daughter cells have only the haploid number of chromosomes.
meiosis I
The second round of division in meiosis, during which the two haploid cells from meiosis I undergo a mitosis-like division without DNA replication to produce four haploid daughter cells.
meiosis II
Stages of meiosis 1
Interphase 1,
Prophase 1
Metaphase 1
Anaphase 1
In this stage of meiosis 1 chromosomes duplicate, forming sister chromatids
Interphase 1,
In this stage of meiosis 1 sister chromatids are attached by a cohesion complex
Interphase 1,
This stage of meiosis 1 like mitosis, has G1, S, and G2 phases
Interphase 1,