Let’s Revise a bit of Unit 1 first!

Lesson starter

1. What word would you use to describe this cell? Why?

2. Describe what would move and to where through osmosis

3% salt

solution

13% salt

solution

membrane

X Y

Lesson starter

3. What would be present in the water after one hour in each tube?

A B

waterStarch +

amylase

Starch

A – sugar

B – water only

C – starch

D – amylase

E - salt

Lesson starter

• 4. a) name parts A and B

• B) which part is destroyed at high temperatures?

AB

Lesson starter

• 5. What word(s) could be used to describe small molecules passing through a membrane and large not?

• 6. active transport and diffusion are two cellular processes. Comment on both their a) concentration gradient and b) energy requirements

Lesson starter

• 7. describe one example of an aseptic technique

THINK, PAIR AND SHARE

• Where do cells come from?

• When does the body need to produce new cells?

• What would control cell division?

Start Timer

2

1

0

Lesson starter

What term is used to describe cell 1 which is swollen with water?

_________________________________________________________________

In what type of solution would you place cell 1 to turn it into cell 4?

________________________________________________________________

Lesson starter

• Make up a rhyme or song to remember the 6 stages of mitosis

Unit 2: Let’s go!

NAT 5 BIO: Unit 2 Multicellular Organisms

1. Producing new cells

2. Control and communication

3. Reproduction

4. Variation and Inheritance

5. Transport systems in plants

6. Transport systems in plants

7. Absorption of materials

Organisation of Cells

Cells

Tissues

Organs

Organ Systems

• This is the order of increasing complexity

• Multicellular organisms have more than one cell type and are made up of tissues and organs.

• Organs perform different functions.

• The cells are specialised for their function.

National 5 Cell Biology

Mitosis

We are learning to:

• State the number of chromosomes found in a human cell

• State that body cells are diploid

• Give examples of when cells need to divide

• State what is meant by mitosis

• Describe the process of mitosis

01/03/2018

What I'm looking for:

• 3 reasons why cells need to divide

• Labelled diagram of a chromosome

• Description of each stage of mitosis

Lesson starter

1. What is mitosis?

2. Where does mitosis occur?

3. What is the difference between a unicellular and multicellular organism?

4. Can anyone guess how many chromosomes there are in every human cell?

What's the difference?

MADE OF ONE CELL

MADE OF ONE CELL

MADE OF ONE CELL

MADE OF MANY CELLS

MADE OF MANY CELLS

MADE OF MANY CELLS

Lesson starter

1. What is the difference between unicellular and multicellular organisms?

2. Give an example of each

3. Why do we need new cells?

Types of Organism

UnicellularOrganisms

with one cell

Amoeba

Bacteria

Yeast

Paramecium

MulticellularOrganisms made

of many cells

Human

Dog

Mouse

Oak tree

Cell Division in a Unicellular Organism

• In the video, you will see a paramecium dividing

• Think!

–How is this different to cell division in a multicellular organism

Blood clotting

Now write a short note on the role of cell division

Cell division in different organisms

Unicellular

Reproduction

Multicellular

Growth and Repair

Mitosis

• Cell division is an important process which increases the number of cells in an organism.

• The division of the nucleus is called MITOSIS.

• Mitosis is important in multicellular organisms as it produces new cells for growth and repair

• Unicellular organisms use mitosis for reproduction **

Mitosis

• Inside nearly all cells is a nucleus.

• The nucleus contains genetic instructions that control all cell activities.

• The instructions are carried on chromosomes.

• Genes on the chromosome control each characteristics.

• Inside human cells there are 23 pairs or 46 single chromosomes. The cell is called a diploid cell.

New terms ***

• Haploid – one set of chromosomes e.g.

sperm and egg cells which have 23chromosomes in total!

• Diploid – two sets of chromosomes e.g. all

other cells (hair, skin, liver etc). These have 46chromosomes in total!

Lesson starter

1. What is mitosis?

2. Where does mitosis occur?

3. Name one diploid cell

4. Name one haploid cell

Stages of mitosis

• Stage 1 - chromosomes appear in the nucleus

(chromosomes shorten and thicken)

• Stage 2 – chromosomes replicate (double)

• Stage 3 – chromosomes line up in the middle of the

cell (equator)

• Stage 4 – spindle fibres appear and pull chromatids to

opposite poles of the cell

• Stage 5 – cytoplasm begins to divide

• Stage 6 – 2 new daughter cells are formed

Stages of mitosis (dance)

• Stage 1 - chromosomes appear

• Stage 2 – they duplicate (double)

• Stage 3 – they line up at the equator

• Stage 4 – spindle fibres pull chromatids to opposite poles

of the cell

• Stage 5 – cytoplasm divides

• Stage 6 – & 2 new daughter cells are formed

Chromosomes

Higher or Lower?

Human body cells have 46 chromosomes but what about these organisms?

Cell Cycle

What happens during mitosis?

Rat skin cell mitosis

•DNA replicates

•Chromosomes appear in the nucleushttps://www.youtube.com/watch?v=gwcwS

ZIfKlM

https://www.youtube.com/watch?annotatio

n_id=annotation_1723462511&feature=iv&

src_vid=gwcwSZIfKlM&v=lpAa4TWjHQ4

•Nuclear membrane disappears

•Chromosomes line up along the equator of

the cell

•Spindle fibres attach to the chromosomes

•Spindle fibres shorten

•Chromatids are pulled apart to each pole of

the cell

•Nuclear membrane reforms

•Cytoplasm divides to produce two identical

daughter cells

Daughter Cells

• Daughter cells have the same number of chromosomes as the parent cell (46). This is important so that the cells can function properly.

I can:

• State the number of chromosomes found in a human cell

• State that body cells are diploid

• Give examples of when cells need to divide

• State what is meant by mitosis

• Describe the process of mitosis

Stem cells

SQA Summary

• Stem cells in animals are unspecialised cells which can divide in order to self- renew. They have the potential to become different types of cell. Stem cells are involved in growth and repair.

• Specialisation of cells leads to the formation of a variety of cells, tissues and organs. Groups of organs which work together form systems.

• A hierarchy exists: cells>tissues>organ>systems.

Lesson starter

• 1. Give 2 functions of xylem cells?

• 2. What is a root hair cell?

• 3. Name the tissue that contains a sieve tube?

• 4. The palisade mesophyll cells contain chlorophyll why is this useful for the plant?

6. Describe the gas exchange that occurs across the stomata?

7.Name the cells that offer the plant protection?

What are stem cells?

• Unspecialised cells

• E.g. a basic animal cell which hasn’t been suited to a specific function

Stem Cell technology

• Stem cells in animals can divide and have the potential to become different types of cell.

•They have the potential to develop into any of the specialised tissues the body needs.

Lesson starter

1. What is a stem cell?

2. What are the two different types?

3. How are they controversial?

Two types of stem cell

• There are 2 types of stem cells:

• Embryonic – from an unborn embryo, can develop into any other cell as it has not developed yet!

• Adult tissue – involved in growth and repair. Found in organs, skin, blood and bone marrow, can develop into cells from the same tissue only!

• E.g. bone marrow can only produce new blood cells and platelets

Bone

marrowPlatelets

Red blood cell

white blood cell

Uses of stem cells

• Stem cells can be use to:

• Make new skin (skin graft)

• Cornea Repair (eyes)

• Bone marrow transplantation (leukaemia)

• Stem cell technology can be controversial as it is unnatural.

• Embryonic stem cell technology is especially controversial as it goes against certain religions and cultures.

• Embryonic stem cell technology is seen by some as taking away a human life.

Controversial?giving rise or likely to give rise (get a reaction) to controversy or public disagreement.

Read pages 79 and 80

• Write down two advantage and two disadvantages of stem cells.

http://www.bbc.co.uk/learningzone/clips/stem-cell-research-and-

medicine/6013.html

Watch the video clip and answer the following questions….

1. What do scientists hope stem cells will enable them to do?

2. What is the easiest way to obtain stem cells at the moment?

3. What are stem cells?

4. Why are stem cells special?

5. How could stem cells be used to help the women shown in the clip?

6. What are the two main ethical issues surrounding the use of stem cells?

Specialised animal cells

https://www.twigonglow.com/film/different-types-of-cell-1042/

Make a table ☺Specialised animal cell Diagram Function

Cheek Epithelium (leave about 4 lines for each)

Red Blood Cell

White Blood Cell

Nerve Cell

Ciliated epithelium

Goblet cell

Smooth Muscle Cell

Cheek epithelium

• Flat, irregular shape

• This allows this layer to be loose so cells can constantly be replaced

*** epithelium = protection

Blood cells

• Red blood cells (RBC)

• Biconcave shape –provides a large surface area

• Contains haemoglobin

• Carried oxygen around body

• White blood cell

• Able to change shape

• Contains sacs of microbe-digesting enzymes

• Kill harmful microbes

Nerve cells (neurons)

• Motor neuron

• Used in nervous system for the transmission of nerve impulses

• Shape – axon (long extended cytoplasm)

Ciliated epithelium tissue

• Here you find two types of cell

• Found in trachea

• Goblet cell

• Cup shape

• Produces mucus

• Traps dirt and germs

• Ciliated epithelial cell

• Hair-like

• Beats upwards sweeping

dirty mucus up away from

lungs

Smooth muscle cell

• Spindle shape (kite)

• This allows cells to form sheets able to contract

• Responsible for peristalsis (movement of food down the oesophagus – contract behind food, relax in front

Specialised plant cells

Make a table ☺Specialised plant cell Diagram Function

Guard Cell (leave about 4 lines for each)

Mesophyll cell

Xylem

Phloem

Root hair cell

Epidermal cell

Guard cell • Sausage shape

• Controls opening & closing of stomata

• Controls gas exchange in plants

• CO2 moves in

• O2 moves out

• Water fills vacuole= swollen

and opens

• Loses water = shrinks and closes

Mesophyll cell

• Contains chloroplasts and chlorophyll for photosynthesis

Xylem and phloem

Xylem

• Dead plant tissue

• Contains rings of lignin for support

• Transports water up the plant like a straw

Phloem

• Live tissue

• Contains a sieve tube and companion cell to control the quantity of sugar going in and out of plant

• Transports sugars up and down the plant

Root hair Cell

• Root hair cells are found in the roots of a plant

• They have a long extension which increases surface area for maximum absorption of water for the plant

1) Specialised Animal Cells

• Design a poster page in your jotter detailing the different specialised cells which occur in humans.

2) Specialised Plant Cells• Design a poster page in your jotter detailing the

different specialised cells which occur in plants.

Quiz time!

Identify the following cells (1-7) and state their function

1 2 3

45

6

7

1. What is meant by a ‘specialised cell’?

2. State the function of red blood cells in our body?

3. State the function of nerve cells in our body?

4. Name 2 essential substances that enter cells?

5. State the function of goblet cells?

6. Why are smooth muscle cells important?

7. What type of cell is

responsible for fighting

infection?

8. Give 2 functions of xylem cells?

9. What is the function of a root hair cell?

10. Name the cell that contains a sieve tube?

11. The palisade mesophyll

cells contain chlorophyll why is this useful for the plant?

12.Name the cells that control the opening and closing of the stomata?

13. Describe the gas exchange that occurs across the stomata?

14.Name the cells that offer the plant protection?