2.6

Question 1

Cytokinesis

Answer 1

Cytoplasmic division following nuclear division resulting in two new daughter cells

Question 2

Mitosis

Answer 2

Nuclear division that produces daughter cells genetically identical to each other and the parent cell

Question 3

M phase

Answer 3

Cell growth stops
Nuclear division
Cytokinesis

Question 4

G0 phase

Answer 4

Cell death

Question 5

G1 phase

Answer 5

Cells grow
Transcription of genes for RNA
Organelles duplicate
Biosynthesis

Question 6

S phase

Answer 6

DNA replicates

Question 7

G2 phase

Answer 7

Cells grow

Question 8

Chromatids

Answer 8

Replications of chromosomes

Question 9

Significance of mitosis

Answer 9

Asexual reproduction
Growth
Tissue repair

Question 10

Prophase

Answer 10

Nuclear envelope breaks down
Centrioles move to opposite poles
Spindle forms

Question 11

Metaphase

Answer 11

Chromosomes attach to spindle equator by centromeres

Question 12

Anaphase

Answer 12

Centromere of each chromatic splits in opposite directions to opposite poles

Question 13

Telophase

Answer 13

Chromosomes reach poles

New nuclear envelope forms

Question 14

Meiosis

Answer 14

Nuclear division that results in formation of cells containing half the number of chromosome of the parent cell

Question 15

Haploid

Answer 15

One set of chromosomes

Question 16

Homologous chromosomes

Answer 16

Matching chromosomes
Same gene
Same place

They may contain different alleles though

Question 17

Prophase 1

Answer 17

Chromatin condenses 
Chromosome super coils
Nuclear envelope breaks down
 Chromosomes come together in their homologous pairs
Cross over of chromatids

Question 18

Metaphase 1

Answer 18

Homologous chromosomes attach to equator by centromere

Question 19

Anaphase 1

Answer 19

Members of each homologous pairs are pulled apart

As crossed over areas are separate this results in allele shuffling

Question 20

Telophase 1

Answer 20

Two new nuclear envelopes form

Haploid

Question 21

Prophase 2

Answer 21

Nuclear envelope breaks down
Chromosomes coil and condense
Spindles form

Question 22

Metaphase 2

Answer 22

Chromosomes attach by spindle to the equator

Random arrangement

Question 23

Anaphase 2

Answer 23

Centromeres divide

Move to poles

Question 24

Telophase 2

Answer 24

Nuclear envelope reforms

Four haploid cells

Question 25

Differentiation

Answer 25

Examples: ``` Epithelial cell Erythrocytes -carry oxygen Neutrophil - ingest invading pathogens Stem cell Sperm cell ```

Question 26

Palisade cells

Answer 26

Long and cylindrical Large vacuole Many chloroplast Cytoskeleton threads and motor proteins to move chloroplasts

Question 27

Guard cells

Answer 27

Light energy is used to treat ATP actively transports potassium ions from surroundings into guard cells Controls stomata

Question 28

Tissue

Answer 28

A group of cells working together to perform a specific function or set of functions

Question 29

Animal tissues

Answer 29

``` Four main types: Epithelial Connective Muscular - skeletal,cardiac,smooth Nervous ```

Question 30

Meristem

Answer 30

Unspecialised plant cells within a plant that can divide and differentiate Thin walls No chloroplasts Do not have large vacuoles

Question 31

Organ

Answer 31

A collection of tissues working together to perform a function

Question 32

Vascular tissues in plants

Answer 32

Xylem and phloem Lignin is deposited into cell walls to strengthen and waterproof them Ends of cells break down so xylem forms a continuous column to carry water and dissolved substances Sieve tubes lose most of their organelles and sieve plates form between them Companion cells retain their organelles and continue metabolic functions of loading sugars into sieve tube elements

Question 33

Stem cells

Answer 33

Undifferentiated Able to express all their genes Divide by mitosis Sources: Embryonic Umbilical chord blood Labs Bone marrow transplant Repair damaged or lost tissue