6) Cell Division and Cellular Organization

Question 1

What is mitosis

Answer 1

Growth of multicellular organism
Repair damage tissues
Method of asexual reproduction
Continuous process

Question 2

Describe Mitosis stage

Answer 2

Interphase - DNA unravelled and organelles replicated. , ATP increased

Prophase - Chromosomes condense , centrioles move at ends of cell , nuclear envelope breaks down

Metaphase -Chromosomes align in the middle of the cell by spindles.

Anaphase - centromere seperates into sister chromatids , pulled in opposite ends

Telophase - chromatids reach opposite poles, Uncoil and are long. Nuclear envelope reforms create 2 nuclei

Cytokinesis - Cytoplasm divides , cleavage furrow , divide cell membrane.
Create 2 daughter cells that are genetically identical.

Question 3

What is Meiosis

Answer 3

Gametes join in fertilisation to form a zygote.
Produce gametes
reduction division
Create haploi cells
Genetically different

Question 4

What happens in Meiosis 2

Answer 4

all the same
Prophase 1 - homologous pairs have bits of chromatids that swall over eachother , cause different combination of alleles (crossing over )
Anophase 2 - sister chromatids seperate ,new cwll inherit one chromatid of each , 4 haploid daughter cells made

Question 5

What are the 2 events that cause genetic variation

Answer 5

Crossing over of chromatids - Meiosis 1 , different alleles in prophase 1

Independant assort of chromasomes Metaphase 1 - Pairs of chromosomes aline at equator and seperate in anaphase 1 randomly.
Different cells have different paternal chromosome combinations

Question 6

Define :
Totipotet
pluripotent
multipotent

Answer 6

Develop into any type of cell - ebryo and placenta
Develop into any cell - exclude placenta and embryo
Develop into a few types of cells

Question 7

Describe Adult Stem Cells

Answer 7

Stem cells in the bone marrow
Multipotent - differentiate into certain stem cells
erythrocytes , neutrophils

Question 8

Describe Embryonic Stem Cells

Answer 8

Found from embryo .
Can be totipotent or pluripotent
DIfferentiate into any stem cell in the body

Question 9

What are the uses of stem cells

Answer 9

repair damage tissues
drug testing on grown tissues
treating neurological diseases eg. alzheimers and parkinsons
Researching developmental biology eg . formation of organs , embryos