cell division

Question 1

what occurs during interphase

Answer 1

growth
prepares for division 
-DNA replicated + checked
-protein synthesis in cytoplasm
-mitochondria grow + divide

Question 2

names and explain the 3 stages of interphase

Answer 2

G1= first growth phase
-proteins that form organelles produced
-organelles duplicate
S= synthesis phase
-DNA replicated in nucleus
G2= second growth phase
-cells grows
-DNA checked

Question 3

what si the difference between mitosis and cytokinesis

Answer 3

M= nucleus divides
C= cytoplasm divides

Question 4

what happens in G0 phase

Answer 4

cell leaves cycle
differentiation- cll becomes specialised to carry out specific function
DNA may be damages so can no longer divide

Question 5

describe what happens in each stage of mitosis

Answer 5

prophase
-chromatin fibre condense forming chromosomes
-nuclear membrane breaks down
-protein microtubules form spindle fibres
-spindle fibres attach to centromeres
metaphase
-chromosomes moved to centre by spindle fibres
- metaphase plate
anaphase
-contromeres divide
-chromatids pulled to opposite ends by fibres
telophase
-chromatids reach poles
-nuclear envelope reforms

Question 6

what happens in stage 1 on meiosis

Answer 6

P1
-crossing over= chromatids entangling
-homologous chromosomes pair up
M1
-homologous airs line up along metaphase plate
A1
-homologous chromosomes pulled to opposite ends
-chromatids stay joined
sections of sister DNA break off and rejoin

Question 7

name some specialised cells

Answer 7

animals
-erythrocytes (red blood cells)
-neutrophils (WBCs with multi-lobed nucleus)
- sperm cells (tail)
plants
-palisade cells (thin cell walls of diffusion)
-root hair cells
-guard cells

Question 8

name the 4 types of animal tissues

Answer 8

nervous tissue
-transmission of impulses

epithelial
-cover body surfaces

muscle
-contracts

connective
-hold tissues together

Question 9

name specialised tissues in animals

Answer 9

squamous epithelium

• thin due to flat cells
• present for raid diffusion across surface

ciliated epithelium

• ciliated epithelium cells with hair like cilia
• sweep away mucus from lungs

cartelage
-prevents ends of bones rubbing together

muscle
-shorten in length to move bones

Question 10

name specialised plant tissues

Answer 10

epidermis
-covers surface

xylem tissue
-structural support

phloem
-transport o organic nutrients

Question 11

name and describe types of potency

Answer 11

ability to differentiate into cell types
totipotent= any type
pluripotent= all tissue types
multipotent= range of cells within tissue type

Question 12

name current and potential uses of stem cells

Answer 12

current
-treat burns
-drug trials
potential
-heart disease
-type 1 diabetes
-parkinsons