Meiosis & Genetics Flashcards
(24 cards)
how many genes do chromosomes have
1500 genes each
how many chromosomes do humans have
46 chromosomes
how many chromosomes do you get from each parent
23
what is the pair of chromosomes from your parents called
homologous
what are homologous chromosomes
they are genes that are the same size and are simmliar
what is meiosis
Meiosis is a kind of cell division that reduces the number of chromosomes by half through the separation of homologous chromosomes.
what happens durring interphase i
interphase carries out a variety of metabolic functions, copies its DNA, and makes proteins.
what is crossing over
Crossing over occurs when a section of one chromosome changes place with a section of its homologous chromosome.
what happens during prophase i
During prophase I, replicated chromosomes, consisting of two sister chromatids, condense.
What happens during metaphase I?
During metaphase I, the pairs of homologous chromosomes line up in the center of the cell.
What happens during anaphase I?
each homologous chromosome is guided by the spindle fibers toward opposite poles of the cell.
what is the final stage of meiosis
telophase - During telophase I, the homologous chromosomes reach opposite poles of the cell.
what do genes effect
they can effect hair, skin, and eye color. and other things like height and face shapes.
what are the 8 stages of meiosis
(prophase I, metaphase I, anaphase I, telophase I) and meiosis II (prophase II, metaphase II, anaphase II, telophase II).
Meiosis is
a process where a single cell divides twice to produce four cells containing half the original amount of genetic information.
processes that occur during meiosis
Crossing Over, Reduction to Haploid, Random Chromatid Assortment, Fertilization.
meiosis
Meiosis is the process by which gametes are produced. Meiosis involves two rounds of cell division and produces four non-identical haploid daughter cells.
mitosis
Mitosis is the process by which most cells in the body divide, involves a single round of cell division, and produces two identical, diploid daughter cells
metaphase ii
metaphase ii is chromosomes positioned at the equator
Compare and contrast sexual reproduction with asexual reproduction.
Asexual reproduction involves one parent and produces offspring that are genetically identical to each other and to the parent. Sexual reproduction involves two parents and produces offspring that are genetically unique.
Define crossing over and list the phase in which it occurs.
Crossing over occurs during prophase I and is the process where two homologous non-sister chromatids pair up with each other and exchange different segments of genetic material to form two recombinant chromosome sister chromatids
Why must sex cells first undergo meiosis before fertilization?
To create haploid gametes that will be used in fertilization; need to reduce the number of chromosomes to n in order to correctly yield a 2n (diploid) organism during fertilization, if not problems may occur
Discuss two ways meiosis contributes to genetic variation.
Crossing over; random lining up of chromosomes at equator
Although mitosis and meiosis both involve cell division, they transmit genetic material in very different ways. What happens when either of these processes goes awry?
Cancer; mutations
