Cellular Reproduction (chapter 16) Flashcards
what are the three main cells discussed in bio 30?
germ, somatic and stem
what is a germ cell?
line of cells that cause gamates (eggs in females, sperm in men)
what are somatic cells? and they have a _______ amount of chromosomes
body cells which have a diploid amount of chromasomes
define diploid
two complete sets of chromosome pairs in a cell (one from mother, one from father)
how many chromosome pairs do body cells have?
23 pairs, 46 single chromosomes
what are stem cells?
cells that are able to differentiate as well as become other types of cells
where does sexual reproduction occur?
germ cells
what does sexual reproduction introduce?
genetic variation
genetic material is found in different forms depending on the stage of the cycle. what are these stages?
chromatin, chromosomes, or chromatids
what is chromatin?
a mixture of dna and proteins that make up chromosomes
what is a chromosome?
structures made of a protein and a singular dna molecule to carry genetic info.
what is a chromatid?
a half of a chromosome, the sister chromatid’s are formed together at a place called the centromere
all somatic cells contain ______ pairs
homologous (23 maternal, 23 paternal)
what do the first 44 chromosomes do and what are the called?
autosomes, carry genetic coding
how many sex chromosomes are there and how do they work?
2 sex chromosomes, determining the sex (male XY, female XX)
what are the two processes that take place in the cell cycle?
divison and replication
what do cells do during mitosis?
cells divide
where does mitosis occur?
somatic cells
all of the cells produced by mitosis are __________ in genetic makeup to the original cells
identical
what is differentiation in mitosis?
when cells become specialized
how many phases does mitosis have?
4
what are the 4 phases of mitosis?
- prophase
- metaphase
- anaphase
- telophase
explain what occurs during prophase of mitosis?
chromosomes condense, create mitotic spindle
explain what occurs during metaphase of mitosis?
chromosomes move to M middle of the cell, spindle fibers attach to the centromeres
explain what occurs during anaphase of mitosis?
chromatids are pulled Away to opposite sides of the cell by spindles
explain what occurs during telophase of mitosis?
chromatids at opposite ends of the cell, spread out to form chromatin, then divided by cytokinesis
what is the main purpose of mitosis?
growth and replace worn out cells
what is cytokinesis?
cytoplasm division
what are the 4 phases of the cell cycle?
growth 1, synthesis, growth 2, mitosis
what is meiosis?
a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes
haploid (meiosis)
the presence of a single set of chromosomes in an organism’s cells (23)
difference between mitosis and meiosis?
mitosis: produces two genetically identical daughter cells, one from each parent cell
meiosis: produces cells that are genetically unique from the parent and are made up of half as much pf the dna contents
where does meiosis take place?
soley in the reproductive tissues of sexually reproducing organisms, takes place in germ cells
meiosis involves _____ cell divisions leading to ______ haploid cells formed
two, four
mitosis involves ________ cell division, leading to ________ diploid cells
one, two
what are the two different kinds of meiosis?
meiosis 1 and meiosis 2
what is meiosis 1?
meiosis 1 is the first division and means the number of cells is doubled but the number of chromosomes is not. this results in half as many chromosomes per cell (23)
what is meiosis 2?
this division is similar to mitosis, the number of chromosomes remains the same
homologous chromosomes
pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical
what is disjunction?
disjunction refers to the seperation of homologous chromosomes or sister chromatids during cell division
when does disjunction take place in meiosis?
anaphase 1 or anaphase 2
what is budding?
an asexual reproductive strat, nucleus of an organism cell divides equally, but cytoplasm divides unequally
what is sporulation?
an asexual reproduction strat, the production of spores
what is regeneration?
an asexual reproduction strat, the development of an entire new body part (ex: lizard tail)
what is vegetative propagation?
an asexual reproduction strat, regeneration in plants
why sexual reproduction?
genetic variation!!
meiosis - special form of cell division occuring only in the ________ of a sexually reproducing organisms where ________ gametes are formed, having ______ the dna contents of the original sex-forming cell
reproductive tissue, haploid, half
how many cell divisions are in mitosis and meiosis?
one in mitosis, two in meiosis
what is the purpose of meiosis 1?
reduction division (separates homologous chromosomes)
what is the purpose of meiosis 2?
separates sister chromatids
prophase of meiosis 1?
chromosomes condense, and pair up with homologous pair
metaphase of meiosis 1?
the homologous pairs of chromosomes line up in the M middle of the cell
anaphase 1 of meiosis?
the homologues pairs are pulled Away and move apart to opposite ends of the cell
telophase 1 of meiosis?
chromosomes gather at the poles of cell, nucleus forms, cell divides via cytokinesis forming 2 daughter cells
prophase of meiosis 2?
each of the daughter cells condenses again
metaphase of meiosis 2?
the chromosomes align in the M middle of the cell
anaphase of meiosis 2?
the sister chromatids separate and are pulled A away to opposite poles of the cell
telophase of meiosis 2?
chromosomes gather at the 2 poles of the cell and the cell divides via cytokinesis forming 2 daughter cells (1n 1c) from each of the two cells from meiosis I
what is spermatogenesis?
the production of mature sperm and occurs from puberty through life in males
what is oogenesis?
development of ova
where does nondisjunction occur?
during anaphase of meiosis 1 or 2
what is karyotyping?
A type of genetic test that analyzes the size, shape, and number of chromosomes in a sample of cells taken from blood, amniotic fluid, bone marrow, or other tissue
mitosis creates _____ cells
body
meiosis creates what?
sperm and egg (gametes)
interphase comes before mitosis and meiosis, what does it do?
duplicated chromosomes (46 chromosomes, 92 chromatids)