Cell Cycle, Mitosis & Meiosis

Question 1

cytokinesis

Answer 1

cytoplasmic division following nuclear division resulting in 2 new daughter cells

Question 2

interphase

Answer 2

phase of cell cycle where the cell is not dividing; it is subdivided into growth and synthesis phases

Question 3

mitosis

Answer 3

type of nuclear division that produces daughter cells genetically identical to each other and the parent cell

Question 4

chromatids

Answer 4

replicates of chromosomes

Question 5

haploid

Answer 5

having only 1 set of chromosomes

Question 6

homologous chromosomes

Answer 6

matching chromosomes containing the same genes at the same places (loci)- may contain different alleles

Question 7

meiosis

Answer 7

type of nuclear division that results in the formation of cells containing half the number of chromosomes of the parent cell

Question 8

differentiation

Answer 8

process by which stem cells become specialised into different types of cell

Question 9

epithelial cells

Answer 9

cells that constitute lining tissue

Question 10

erythrocyte

Answer 10

red blood cell

Question 11

neutrophil

Answer 11

type of white blood cell that is phagocytic

Question 12

stem cell

Answer 12

unspecialised cell able to express all its genes and divide by mitosis

Question 13

genome

Answer 13

genetic material within an individual

Question 14

gene pool

Answer 14

all the genetic material within a population

Question 15

guard cells

Answer 15

in leaf epidermis, cells that surround stomata

Question 16

palisade cells

Answer 16

closely-packed photosynthetic cells within leaves

Question 17

root-hair cells

Answer 17

epidermal cells of young roots with long hair-like projections

Question 18

tissues

Answer 18

group of cells that work together to perform a specific function

Question 19

meristem

Answer 19

area of unspecialised cells within a plant that can divide and differentiate into other cell types

Question 20

organ

Answer 20

collection of tissues working together to perform a function

Question 21

phloem

Answer 21

tissue that carries products of photosynthesis in solution within plants

Question 22

xylem

Answer 22

tissues that carries water and mineral ions from the roots to all parts of the plant

Question 23

organ system

Answer 23

a number of organs working together to carry out an overall life function

Question 24

why do cells divide

Answer 24

for growth and repair

Question 25

which cells undergo division in the body and when

Answer 25

skin cells- replacement and repair | epithelial cells- mouth and lining of stomach

Question 26

purpose of controlled sequence of cell division with checkpoints

Answer 26

prevent uncontrolled division leading to tumours detect and repair damage to DNA ensure DNA isn't reversed and only replicated once

Question 27

5 phases of the cell cycle

Answer 27

``` M phase G0 phase G1 phase S phase G2 phase ```

Question 28

function of mitosis (M phase)

Answer 28

asexual reproduction, growth, tissue repair

Question 29

structure of chromosomes

Answer 29

made of DNA, protein and small amount of RNA, very large molecule, coiled, 4 chromatids and 1 centromere

Question 30

types of protein involved

Answer 30

histone scaffold polymerases

Question 31

histone proteins

Answer 31

large number of positive amino acids that bind to phosphate group of DNA so stabilise structure

Question 32

polymerases

Answer 32

enzyme transcription + DNA replication prior to divisions of chromosomes

Question 33

process of cytokinesis

Answer 33

after mitosis, cell splits into 2 and each new cell contains a nucleus

Question 34

animal cells in cytokinesis

Answer 34

cytoplasm 'nips in' due to membrane folding inwards

Question 35

plant cells in cytokinesis

Answer 35

end plate forms where spindle equator of the cell was situated, new cellulose and membrane are laid down along the cell plate

Question 36

number of divisions in meiosis

Answer 36

2

Question 37

stages in divisions of meiosis

Answer 37

prophase, metaphase, anaphase, telophase

Question 38

fusion of the nuclei of gametes form

Answer 38

a zygote

Question 39

a diploid zygote is formed by

Answer 39

fertilisation

Question 40

gametes are produced in

Answer 40

the ovaries or testes

Question 41

phases of interphase

Answer 41

G1, S, G2

Question 42

why is the synthesis phase rapid

Answer 42

exposed DNA base pairs are more susceptible to mutagenic agents so reduces chances of spontaneous mutations

Question 43

what is tubulin

Answer 43

a cytoskeleton protein

Question 44

structure of the spindle

Answer 44

3D structure lines of latitude on a globe in plant cells they form from cytoplasm

Question 45

why are chromatids of each chromosome no longer identical in prophase 2

Answer 45

crossing over in prophase 1

Question 46

4 main tissues in animal body

Answer 46

epithelial connective tissues muscle tissues nervous tissues

Question 47

epithelial

Answer 47

lining tissue

Question 48

connective tissues

Answer 48

hold structures together & provide support e.g. blood,bone,cartilage

Question 49

muscle tissues

Answer 49

made of cells that are specialised to contract & cause movement

Question 50

nervous tissues

Answer 50

made of cells specialised to conduct electrical impulses

Question 51

pluripotent

Answer 51

refer to stem cells- capable of giving rise to several different cell types

Question 52

examples of differentiating cells in animals

Answer 52

erythrocytes neutrophils from stem cells in bone marrow

Question 53

examples of differentiating cells in plants

Answer 53

xylem tissue | phloem tissue from meristem cells (like cambium)