Cellular division and organisation

Question 0

Interphase

Answer 0

DNA is replicated and checked
Organelles replicated
ATP content increased
Cell increases in size
Largest part of cell cycle

Question 1

Prophase

Answer 1

Chromosomes condense (visible)
Centrioles make spindle (from fibrous proteins)
Nuclear envelope breaks down

Question 2

Metaphase

Answer 2

Chromosomes line up, middle of cell

Spindle attaches to centromeres

Question 3

Anaphase

Answer 3

Centromeres divide, chromatids separated

Spindle contracts, chromatids pulled to poles

Question 4

Telophase

Answer 4

At poles chromatids uncoil=chromosomes
2 nuclear envelopes form
2 genetically identical daughter cells
Same number of chromosomes as parent cell
(cytokinesis next stage)

Question 5

Mitosis used for

Answer 5

Growth of organism
Tissue repair
Old cell replacement
Asexual reproduction

Question 6

Define cell cycle

Answer 6

A continuous process, the events as one parent cell divides to produce two new daughter cells.

Question 7

Define differentiation

Answer 7

The ability of a cell to specialise to for a particular type of cell

Question 8

Define stem cell

Answer 8

Cells that aren’t specialised or differentiated, maintaining the capacity to undergo mitosis and differentiate into a range of cell types

Question 9

Stem cells in humans and plants and what they differentiate into

Answer 9

Animal (bone marrow) erythrocytes and neutrophils
Embryonic, anything?
Plant (meristem tissues) cambium into xylem and phloem

Question 10

Budding in yeast

Answer 10

Asexual reproduction, mitosis
One nucleus moves to one side of cell
Cell wall bulges
Nucleus moves into bulge
Bulge constricts, separate daughter cell

Question 11

Meiosis produces cells that are

Answer 11

Not genetically identical
Gametes
Haploid

Question 12

Erythrocyte specialisation

Answer 12

Carry oxygen in blood
Small, flexible (fit through capillaries)
Packed with haemoglobin (bind with O2)
No nucleus (more space Hb)
Biconcave shape (large SA take up O2)

Question 13

Neutrophil specialisation

Answer 13

Engulf, digest foreign matter or old cells
Flexible shape (move through tissues)
Lobed nucleus (move through membranes)
Many ribosomes (make digestive enzymes)
Many lysosomes (hold enzymes)
Many mitochondria (release energy for activity)
Well-developed cytoskeleton (enable movement)
Membrane-bound receptors (recognise materials destroy)

Question 14

Sperm cell specialisation

Answer 14

Carry paternal chromosomes to egg
Flagellum (rapid movement)
Acrosome (digest egg surface)
Small (easier movement)
Many mitochondria (release E for rapid movement)

Question 15

Epithelial cell specialisation

Answer 15

Surfaces
Squamous, flat thin (large area, short diffusion distance)
Ciliated (move mucus)
Cuboid (barrier)
Many glycolipids+glycoproteins in plasma membrane (hold cells together as a surface)

Question 16

Palidade cell specialisation

Answer 16

For photosynthesis
Elongated (many chloroplasts)
Many chloroplasts (absorb most light)
Cytoplasmic streaming (move chloroplasts, less damage)
Starch grains (store photosynthesis products)

Question 17

Root hair cells

Answer 17

Absorb water and mineral ions form soil
Long extension (increase SA)
Active pumps in plasma membrane (absorb mineral ions active transport)
Thin cell wall (reduce barrier for ions and water movement)

Question 18

Guard cell specialisation

Answer 18

Control stomatal opening
Active pumps in cell surface membrane (move mineral ions in/out, alter water potential)
Unevenly thickened wall (cell change shape as more turgid)
Large vacuole (take up water, expand open stomata

Question 19

Homologous pair of chromosomes

Answer 19

Same shape and size
Centromere same position
Same genes same positions

Question 20

Tissue

Answer 20

Collection of cells work together perform a particular function
Eg ciliated epithelium
Xylem
Phloem

Question 21

Organ

Answer 21

Collection of tissues working together to perform a common function

Question 22

Organ system

Answer 22

Two or more organs working together to perform a life function

Question 23

Cell signalling

Answer 23

Communication and coordination between cells

The shape of the signal molecule is complementary to the shape of the receptor molecule on the target cell.