chapter 13,12 and 16

Question 1

What are the phases of mitosis

Answer 1

prohase, prometaphase, metaphase, anaphase and telophase (overlapping with the latter stages of mitosis, sytokinesis completes the mitotic phase)

mitosis is part of cell cycle. the mitosis alternates with a much longer interphase

Question 2

interphase exit out of…

Answer 2

interphase can be divided into three phases: G1, the Sphase and G2

Question 3

explain G1, the S phase and G2 phase

Answer 3

During all three the phases the cell grwos by producing proteins and cytoplasmic organelles. duplication of chromosomes crucial for eventual division of the cell only happen during the S phase. the cell grows (G1) the cell continues to grow as it copies its chromosomes (S) grows more as it completes preparations for cell division (G2)

organelles such as mitochondria and endoplasmic reticulum

Question 4

what happends in the G2 of interphase (mitosis)

Answer 4

• a nuclear envelope encloses the nucleus
• two centrosomes have formed by duplication of a single centrosome. centrosome are regions in animal cells that organise the microtububules of the spiindle. each chromosome contains two centrioles

chromosomes, duplicated during the s phase cannot be seen individually

Question 5

what is a chromatin

Answer 5

together the entire complex of DNA and proteins that is building material of the chormosomes.

Question 6

what happens in the prophase (mitosis)

Answer 6

• the chromatin fibers become more tightly coiled, condensending into descrete chromosomes observable with a light telescoop
• the nucleoli disappear
• each duplicated chromosome appears as two identical sister chromatids joined at thair centromeres and often, all along their arm by cohesins, resulting in sister chromatid cohesing
• the mitotic spindle begins to form. it is composed of the centrosomes and the microtubules that extend from them. the radial array of shorter microtubules that extend from centrosomes are called aasters.
• the centrosomes move away from eachother propelled partly by the lengthening microtubules between them.

class notes:
chromosomes supercoil
nuclear envelope breaks down to smal

Question 7

what is a nucleolus

Answer 7

nonmembranous structure involved in production of ribosomems: a nucleus had one of more nucleoli. here a type of RNA is synthesized. also in the nucleolus, proteins imported from the cytoplasm are assembles with rRNA into large and small subunits of ribosomes (conection to ribosomes)

de kern van de nucleus

Question 8

somatic cells

Answer 8

al body cells exept reproductive cells (gametes)

Question 9

cytokinesis

Answer 9

the division of the cytoplasm (one cell become two, each the genetic equivelent to the parent cell)

Question 10

what is inheritance or heredity?

Answer 10

the transmission of traits from one generation to another