1Biology - Cell Division, Diversity...

Front 1

MItosis only occupies a small percentage of the cell cycle, what does the remaining percentage include?

Back 1

Copying and checking of genetic information

Front 2

What are the 5 main stages of mitosis?

Back 2

Interphase, prophase, metaphase, anaphase
telophase (IPMAT = If Penguins MATtered)

Front 3

Describe interphase (3) - mitosis
IPMAT

Back 3

DNA is unravelled and replicated
Organelles are replicated
ATP content is increased

Front 4

Describe prophase (4) - mitosis
IPMAT

Back 4

Chromosomes condense (shorter and fatter)
Centrioles move to opposite ends of the cell
Spindle (network of protein fibres) forms
Nuclear envelope breaks down

Front 5

Describe metaphase (1) - mitosis
IPMAT

Back 5

Chromosomes (each with 2 chromatids) line up along the middle of the cell and become attached to the spindle by their centromere

Front 6

Descrive anaphase (2) - mitosis
IPMAT

Back 6

Centromeres divide, separating each pair of sister chromatids
Spindles contract, pulling chromatids to opposite ends of the cell, centromere first

Front 7

Describe telophase (3)- mitosis
IPMAT

Back 7

Chromatids uncoil and become long and thin again (are now chromosomes again)
Nuclear envelope forms around each two groups of chromosomes
Cytoplasm divides

Front 8

What is a homologous pair of chromosomes?

Back 8

Chromosomes that have the same genes and are the same size but have different versions of these genes.
EG - half our chromosomes came from our father, and half from our mother

Front 9

Why is mitosis important for growth, repair and asexual reproduction?

Back 9

GROWTH: creates more cells of the same (EG - human skin) so the overal tissue etc, can expand
REPAIR: to replace old, damaged cells
ASEXUAL REPRODUCTION: new organisims are created by a single cell, these new organisims are genetically identical to their parent

Front 10

Cells that are produced as a product of meosis are NOT....

Back 10

... Genetically identical

Front 11

What is a stem cell?

Back 11

An unspecialised cell that can become any cell

Front 12

What is differentiation?

Back 12

Stem cells dividing to become new, specialised cells

Front 13

What is differentiation in reference to erythrocytes (red blood cells) and neutrophils (white blood cells)? (4)

Back 13

1. Bones are living organs
2. Containing nerves and blood vessels
3. Main bones in the body have marrow in the centres
4. Here, adult stem cells DIFFERENTIATE to replace worn out red blood cells

Front 14

What is differentiation in reference to the production of xylem cessels and phloem sieve tubes from cambium? (4)

Back 14

1. In plants, stem cells are found in the cambium
2. In the root and stem, these cells divide and DIFFERENTIATE to become xylem and phloem
3. The vascular cmbium forms a ring inside the root and shoots
4. The cells divide and grow out from this ring

Front 15

How are erythrocytes (red blood cells) specialised for their particular function? (2)

Back 15

1. Biconcave shape provides a large surface area for gas exchange
2. No nucleus so more room for haemoglobin

Front 16

How are neutrophils (white blood cells) specialised for their particular function? (2)

Back 16

1. Flexible shape to engulf foreign particles/pathogens
2. Many lysosomes in cytoplasm containing digestive enzymes to break down engulfed particles

Front 17

How are epithelial cells specialised for their particular function? (2)

Back 17

1. Cells are joined by interlinking membranes and a membrane at their base, these membranes contain cilia to move foreign particles away from the organ they are protectiong (EG - lungs)
2. Others have microvill which increase the surface area of the cell

Front 18

How are sperm cells specialised for their particular function? (3)

Back 18

1. Flagellum to swim to the egg
2. Many mitochondria to provide energy to swim
3. Acrosome contains digestive enzymes to enable the sperm to penetrate the surface of the egg

Front 19

How are palisade cells specialised for their particular function? (2)

Back 19

1. Contain many chloroplast for photosynthesis
2. Thin walls for easy diffusion of gases (EG - CO2 diffusing in)

Front 20

How are root hair cells specialised for their particular function? (3)

Back 20

1. Large surface area for absorption
2. Thin, permeable cell wall for entry of water and ions
3. Cytoplasm contains extra mitochondria to provide energy for active transport

Front 21

How are guard cells specialised for their particualr function? (2)

Back 21

1. Tiny pores in surface for gas exchange
2. Thin outer walls and thick inner walls force them to bend outwards, opening the stomata

Front 22

Meaning of:
Tissue
Organ
And organ system?

Back 22

Different cells are organised into tissues, different tissues are organised into organs and different organs are organised into organ systems

Front 23

How are cells organised into tissues?

Back 23

They are all specialised to work together to carry out a particular function

Front 24

Describe squamous and ciliated epithelia

Back 24

SQUAMOUS: A single layer of flat cells lining a surface (EG - alveoli in lungs)
CILIATED: layer of cells covered in cilia (EG - the trachea)

Front 25

Describe xylem and phloem tissue.

Back 25

XYLEM: Transports water and supports the plant (contains xylem vessell cells and parenchyma cells)
PHLOEM: Transports sugars around the plant (made of sieve cells, companian cells and ordinary plant cells). Each sieve has end walls with holes in them so sap can easily move through them (sieve plates)

Front 26

What is the importance of cooperation between cells, tissues, organs and organ systems?

Back 26

1. Different cells are specialised for different functions
2. Each cell depends on other cells to carry out the functions that itself cannot
3. This means they must all cooporate together to keep the organism alive and running