Biology 3 Flashcards
(32 cards)
list the steps of Mitosis
1- Prophase 2- Metaphase 3- Anaphase 4- Telophase 5- Cytokinesis
List the steps of Meiosis
MEIOSIS I 1- Prophase I 2-Metaphase I 3- Anaphase I 4- Telophase I and Cytokinesis MEIOSIS II 1- Prophase II 2- Metaphase II 3- Anaphase II 4- Telophase II and Cytokinese
what is a Centromere
the part of a chromosome that links sister chromatids
What are Chromatids?
One copy of a newly copied chromosome which is still joined to the other copy by a single centromere
what is Chromatin?
the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.
what are Chromosomes?
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
what is crossing over in meiosis? and in which phases does it occur?
Crossing over occurs between prophase 1 and metaphase 1 and is the process where homologous chromosomes pair up with each other and exchange different segments of their genetic material to form recombinant chromosomes
what is Cytokinesis?
he cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.
Define Diploid
(of a cell or nucleus) containing two complete sets of chromosomes, one from each parent.
Down Syndrome
Down syndrome is a genetic disorder in which, most often, a third copy of chromosome 21 is present in cells because of an abnormal cell division when the egg and sperm first meet.
What are the steps of interphase?
G1– start
S Phase– Double Chromosomes
G2– Mitosis
what is a Gamete?
a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote. (sperm/egg)
Histone
any of a group of basic proteins found in chromatin.
what are Homologous chromosomes?
Homologous chromosomes are similar but not identical.
what is the second stage of cell division, between prophase and anaphase, during which the chromosomes become attached to the spindle fibers.
Metaphase
What is Mitosis?
a part of the cell cycle in which chromosomes in a cell nucleus are separated into two identical sets of chromosomes, and each set ends up in its own nucleus.
What is Nondisjunction
If nondisjunction occurs during anaphase I of meiosis I, this means that at least one pair of homologous chromosomes did not separate. The end result is two cells that have an extra copy of one chromosome and two cells that are missing that chromosome.
Prophase
Prophase is the first phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells (prep)
what is telophase?
the final phase of cell division, between anaphase and interphase, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.
Trisomy
a condition in which an extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities.
What happens in Prophase one
homogolous chromosomes pair up and exchange segments
What happens in Metaphase One
Pairs of homologus chromosomes line up
what happens in Anaphase one
pairs of homologus chromosomes split
what happens in telophase one and cytokinesis
2 haploid cells form
