TTC FIRST TERM

EXAM BIO SEMINAR

2012

WELCOME!LET’S WORK HARD

TOGETHER!

JaySze Yong

Let’s start!Syllabus of the day:

Chapter 1 : Introduction to Biology

Chapter 2 : Cell Structure and Organisation

Chapter 3 : Movement of Substances Across the Plasma

Membrane

It’s not about how many times have you studied, but how much did you understand

Introduction of Biology① Study of Biology

② Scientific Investigation

→ Study of Biology

What is Biology? The study of life.

Why is it important? To provide a better understanding on ourselves(living things) and surrounding environment.

• Understand ourselves and our surrounding environment.

• Understand the interaction between living things and the environment.

• Appreciate and be thankful for the diverse variety of living things.

Fields of Study in Biology• Genetics • Anatomy• Virology• Mycology• Microbiology• Botany• Entomology• Ecology• Zoology

• Physiology• Bacteriology• Histology• Embryology• Taxonomy

Question!• Name a five examples of fields of study in Biology.

• State three branches of Biology and explain.

→ Scientific Investigation• Scientific methods are used to proof whether an event is a fact or a

myth….

• Its about carrying out experiment!

• Scientific method : Process of gathering facts of a problem about an event or phenomena.

• Few steps involved in scientific method. *In a fixed sequence!*

☺ Steps involved….

1.IDENTIFYING A PROBLEM

2.MAKING A HYPOTHESIS

3.PLANNING INVESTIGATION

4.IDENTIFYING AND CONTROLLING

VARIABLES

5.CONDUCTING EXPERIMENT

6.COLLECTING DATA

7.ANALYSING AND INTERPRETING DATA

8.MAKING CONCLUSIONS

9.WRITING REPORT

Must memoriseall the steps! Including the descriptions.

① Identifying problem:

• Observe a specific phenomenon, determine the problem to be answered.

① Making hypothesis:

• Hypothesis: A smart guess or prediction to explain the problem.

• Statement to explain relationship between manipulated variable and responding variable.

• The statement to be tested throughout the experiment.

② Planning investigation:

• Plan experiment to test hypothesis.

• Determine the ingredients needed! Eg: Materials, apparatus, procedures..

③ Identifying and controlling variables:

• Identify manipulated, responding, fixed variables.

⑤ Conducting experiment:

• Carry out experiment as planned to test hypothesis!

• Observe all variables, handle all apparatus and materials, collect results.

⑥ Collecting data:

• Collect and record data.

• Data collected based on variables.

• Present data in table/ graph/ diagrams/ charts.

⑦ Analysing and interpreting data:

• Explain your results.

• Analyse relationship between manipulated and responding variable (hypothesis).

⑧ Making conclusions:

• Judge whether hypothesis is correct.

• Decide whether the hypothesis is valid. If results = hypothesis, then hypothesis is VALID.

• General statement about results based on hypothesis.

⑧ Writing report:

• Report written based on procedures and findings of experiment.

• *Start from problem statement, then objective, hypothesis, variables……lastly, conclusion*

Cell Structure and Cell Organisation Question before we start! What is a cell?

The basic units of life.

Here we come the main characters of the chapter…

Remember all the name of organelles and functions of them.Organelles? Little organs in a cell.

All cells:

• Little tiny structures called organelles(‘little organs’) to carry out special functions.

• A big fluid tank which carries all organelles called cytoplasm.

• Thin membrane coat wrapping the whole cell called plasma membrane.

However!Only plant cell:Extra outer boundary protect coat surrounding plasma membrane called cell wall.

Question!• Compare the similarities & differences between animal cell and plant cell!

Similarities

Both have plasma membrane, cytoplasm, nucleus, mitochondria, Golgi apparatus, Endoplasmic reticulum

Animal cells Differences Plant cells

Irregular Shape Regular

Absent Cell Walls Present, made up of cellulose

Absent Chloroplasts Present, contains chlorophyll

Absent. Even if present, in small

sizes and numerous in amount

Vacuoles Large

In form of glycogen. Food storage In form of starch

Present Centrioles Absent

Useful cuties in a cell! = Organelles

NUCLEUS : Controls all activities of cell.

ER(Endoplasmic Reticulum): Rough –Synthesise protein.Smooth – Synthesiselipids.

Golgi Apparatus : Responsible in modifying, packaging, transporting of proteins.

Uses light energy and carry out photosynthesis.

Non – organelles of a cell:(Anything that is not inside the cytoplasm AND not wrapped in a membrane)

① Cytoplasm② Cell wall③ Plasma membrane

Formation of spindle during cell division.

‘Power house’, Synthesiseenergy in the form of ATP.

Vacuole: Stores water, sugar, minerals etc.Maintains turgidity of cells.

Question!Label!

Chloroplast

Vacuole

Nucleus

Rough ER

Smooth ER

Golgi Apparatus

Lysosome / Normal vesicle

Plasma membrane

Cell Wall

Mitochondrion

Cytoplasm

Special cases…

• Some organelles are found high in numbers in certain cells. Examples:

• Many mitochondria : Sperm cells, muscle cells, meristematic cells of plants.

• Many chloroplasts : Palisade mesophyll cells

• Many Rough ER & Golgi Apparatus : Pancreatic cells, Cells in salivary gland (For enzymes)

Cell Organisation• TWO types of organisms :

1. Unicellular Organism : Single-cell organism.

Examples: Paramecium sp., Amoeba sp.

2. Multicellular Organism : Larger organism with MORE THAN ONE CELL.

Examples: Animals, Plants, Insects….

Living Processes of Unicellular OrganismsAmoeba sp. –

Movement/Locomotion :

• Amoeba moves by cytoplasmic projection,

by extending pseudopodia and anchoring

the tips onto an object.

• This is followed by the flow of cytoplasm

into the pseudopodia.

• This form of locomotion a.k.a amoeboid

movement.

Reproduction

• Asexually by binary fission and forming spores.

• In a favourable environment where food is abundant, Amoeba reproduces by binary fission.

•

• In a harsh environment where food is scarce and dry, Amoeba forms spores.

Feeding

• Feeds on bacteria and diatoms.

• Engulfs food by phagocytosis.

• Nutrition in Amoeba sp.

• Amoeba sp. approaches the food particles.

• 2 pseudopodia extend out and enclose the food particles.

• The food particles are packaged in a food vacuole which fuses with lysosome containing lysozyme.

• The food particles are digested by the lysozyme. The resulting nutrients diffuse into the cytoplasm and assimilated.

Living Processes of Unicellular OrganismsParamecium sp.

Movement

• Rhythmic beating of the cilia. (singular, cilium)

• This action results in moving forward while

rotating and spiraling along its axis.

Feeding

• Feeds on microscopic organisms.

• Nutrition in Paramecium sp is as follows:

• The rhythmic beating of cilia along a

mouth-like opening (oral groove) sweeps

water and suspended food particles into

the cytostome.

• In the cytostome, food vacuoles

containing the food particles are formed.

• The content of the food vacuoles are

digested by hydrolytic enzymes from the

cytoplasm.

• Nutrients from the digested food then

dissolve and diffuse into the cytoplasm and

are used to generate energy.

• Undigested materials are released

• Reproduction

• Paramecium sp reproduces asexually as well as sexually.

• Paramecium sp has 2 nuclei. The macronucleus controls cellular metabolism of the cell and is also necessary for asexual reproduction while the micronucleus is required for sexual reproduction.

• In a favourable environment, Paramecium sp. reproduces rapidly by binary fission. Sexual reproduction in Paramecium sp., known as conjugation, takes place when the environmental conditions are not favourable.

Multicellular OrganismCell specialisation is a process of change and adaptation that a cell undergoes to give special structures and specific functions. It gives rise to various types of cells in multicellular organism.

Cell

Tissue

Organ

System

Organism

Various systems make up multicellular organism.

A system consists of several organs that work together to carry out a living process.

A group of tissues that cooperate closely to perform specialisedfunction.

A group of cells which are similar in structure and are designed to perform specialisedfunction.

The basic unit of organism. Undergoes cell specialisation to form various types.

Summary

Reminder for you to remember what did we learn!

Homeostasis• Homeostasis: The maintenance of a relatively constant internal

environment for optimal functions of cell.

• Internal environment = Interstitial fluid

THE END