Cell Division

Question 1

what is interphase?

Answer 1

the first stage of the cell cycle, also called the growth stage. is where the somatic cell spends most of its life

Question 2

what are the 3 phases in interphase?

Answer 2

G1 phase: rapid growth and metabolic activity
S phase: DNA synthesis and replication into sister chromatids
G2 phase: allows the cell to rebuild tis energy reserves to prepare for division

Question 3

what are the 2 main processes in cel division? briefly describe them.

Answer 3

1. Mitosis: the division of the genetic material and contents of the nucleus
2. Cytokinesis: the division of the cytoplasm and organelles into 2 separate cells

Question 4

list all phases of mitosis

Answer 4

prophase, metaphase, anaphase, and telophase

Question 5

describe prophase

Answer 5

the chromatids condense as nucleolus and nuclear envelop disappear, the centrioles move toward opposite poles as the spindle apparatus forms

Question 6

describe metaphase

Answer 6

the chromosomes become aligned on the equator, the spindle apparatus continues to form

Question 7

describe anaphase

Answer 7

centromeres split and chromatids move to opposite poles, as spindle microtubules shorten

Question 8

describe telophase

Answer 8

nuclear envelopes and nucleoli form, chromosomes lengthen and cytokinesis is initiated

Question 9

describe cytokinesis

Answer 9

• indentation forms in cell membrane, until the membrane is pinched in two
• the cytoplasm and organelles divide between the two halves
• ends with the separation of 2 genetically identical daughter cells

Question 10

difference of mitosis and cytokinesis in plant cells

Answer 10

• plant cell have no centrioles

- cell wall doesn’t pinch during cytokinesis, instead a cell plate forms between the 2 daughter nuclei

Question 11

mitosis

Answer 11

• occurs in somatic cells
• 1 duplication of nuclear material
• 1 division of the nucleus
• cytokinesis occurs after nuclear division
• produces 2 identical daughter cells, each one c containing 2n chromosome

Question 12

DNA

Answer 12

• is where the genetic information of a cell is contained

- it is a moleucle of nucleic acid that governs processes of heredity in cells

Question 13

chromosome

Answer 13

• it is a length of DNA and its associated proteins

- in eukaryotic cells, they are found in the nucleus

Question 14

chromatin

Answer 14

-genetic material appears as a bunch of long, interwinded strands known as chromatin

Question 15

centromere

Answer 15

the pinched-in region in the chromosome

Question 16

homologous chromosome
sex chromosome
genes
alleles

Answer 16

• similar looking chromosomes. are different in that they carry different alleles
• are called X and Y, determine the sex of an individual
• areas of DNA that contain specific genetic information
• different forms of the same gene

Question 17

monoploid
diploid
haploid

Answer 17

• a cell that contains only 1 set of chromosomes (n)
• a cell that contains 2 sets of chromosomes (2n)
• a cell that contains unpaired chromosomes

Question 18

independent assortment

Answer 18

when the maternal and paternal chromosomes vary the pole their facing, leading to different combinations of the parent chromosomes

Question 19

crossing over

Answer 19

when non-sister chromatids are in synapses, and exchange pieces of chromosomes. the result is individual chromosomes containing some genes from mom, and some from dad

Question 20

nondisjunction

Answer 20

when chromosomes or chromatids do not separate as they should during meiosis