cell cycle, mitosis, meiosis test

zygote

fertilized egg

gametes

sex cells

centromere

structure that connects the duplicate halves of the chromosomes

fertilization

the union of the sperm and egg

spindle

network of fibers that push and pull the chromosomes around in the cell during division

centrioles

organelle that organizes the construction of the microtubules for cell division

sperm cell

male gamete cell

egg cell

female gamete cell

reproductive cells

cells formed by meiosis

meiosis

process that has two divisions and reduces the chromosome number in half

diploid

chromosome number in all body (somatic) cells - full set of chromosomes - 2 of each kind of chromosomes

haploid

chromosome number in the gametes - half the chromosome number of body cells

23

human haploid number

46

human diploid number

tetrad

four sister chromatids in a homologous pair of chromosomes; forms during Prophase I; leads to crossing over

chromosomes

structures that carry the genetic information from one generation to the next

cleavage furrow

in a dividing animal cell, the indentation where cytoplasmic division will occur

cell plate

forms in plant cells to form new cell membrane and cell wall during telophase

when a cell grows too large, some problems that it faces includes;

too much demand placed on the DNA, obtaining enough food for the cell, and getting rid of wastes a large cell would produce

after mitotic division, how many chromosomes does each offspring cell contain as compared to the parent cell?

same number as parent cell

type of division where crossing over can occur

meiosis

used for growth and repair of cells, tissues, etc

mitosis

this division results in cells that are different from the parent cell

meiosis

type of division that cuts the chromosome number in half

meiosis

type of division of the nucleus in somatic cells

mitosis

metaphase

sister chromatids are lined up in the middle of the cell

prophase

nucleolus and nuclear membrane disappear and the chromosomes coil and condense to become visible

anaphase

sister chromatids are pulled apart to opposite sides of the cell

telophase

last phase of cell division, chromosome are in two new cells and nuclear membranes start to reform

cytokinesis

division of the cytoplasm

Interphase

period of the cell cycle between cell divisions;

G1, S, G2; cell spends the majority of time in this stage

G1 phase

stage of interphase in which cell grows and performs its normal functions; double number of organelles

S phase

DNA replicates

G2

cell prepares for division

correct order of cell cycle

interphase, mitosis, cytokinesis

phase of meiosis when crossing over occurs

Prophase I

offspring of this type of reproduction have a much better chance of adapting and surviving in a changing environment

sexual reproduction

mating is not required and offspring is identical to parent

asexual reproduction

involved egg, sperm, and fertilization

sexual reproduction

crossing over

increases the variety of genes in the chromosomes

How is cancer different from a normal cell in relation to the cell cycle?

A cancer cell does not follow normal cell division. The protein regulators that control the cell cycle are not functioning properly. Cancer cells will divide uncontrollably forming tumors that will invade healthy tissue.

How does crossing over occur during Meiosis?

During Prophase I, the homologous chromosomes are joined together and pieces of the sister chromatids can break off and reattach to their corresponding homologous chromsome. The genes exchange spots on the chromosomes.

Homologous chromosomes

How does crossing over contribute to genetic variation in sperm and egg cells?

After crossing over occurs, the resulting chromatids will now have genes from their sister chromatid. There is an exchange of genes and this will increase the variation during the formation of the egg and sperm cells.