Introduction to Biology

Biology Introduction

• Biology is the study of living things
• Biology can be divided into branches, including botany, zoology, physiology, genetics, biochemistry, microbiology, geology, and virology
• A biology examination typically includes three papers: two theory papers and one practical paper

Unit 1.1: Studying the Environment and Organisms

• A backyard garden provides an opportunity to observe living and non-living things
• Matter is anything that occupies space and has mass
• Living and non-living things are both made of matter
• Non-living things that were once alive are made of organic matter
• Non-living things that have never been alive are made of inorganic matter
• Examples of inorganic matter are air, rocks, metals, and water
• Examples of organic matter are wood, petroleum, and feces
• Living things have different sizes and shapes, but share similarities and carry out similar life processes

Processes in Living Organisms

• Living organisms are distinguished from non-living organisms through the processes they carry out
• These processes are driven by chemical reactions
• Seven characteristics distinguish living organisms

Reproduction

• Reproduction is the process where living organisms produce offspring
• Reproduction is necessary for organisms to replace dead members of their species and increase population
• Some organisms reproduce sexually
• Other organisms reproduce asexually

Movement

• Movement is more noticeable in animals, while plants move through growth
• Movement in living things is "at will", whereas non-living things are moved by external forces

Growth

• Growth is a permanent increase in an organism's size, involving an increase in cell number and mass

Feeding

• All living organisms feed
• Organisms obtain materials from their environment for bodily use
• Some organisms create their own food from basic materials
• Other organisms consume pre-made food

Respiration

• Respiration is the process in which living organisms break down carbohydrates in their cells to obtain energy
• The energy released is used for growth, warmth, reproduction, and other life processes
• Some organisms respire anaerobically while others respire aerobically, both plants and animals

Excretion

• Excretion is the removal of metabolic waste from the body
• Chemical reactions like respiration make harmful substances that must be removed to prevent tissue damage
• The liver produces urea and uric acid, which are harmful and removed through excretion

Sensitivity

• Sensitivity or irritability is an organism’s ability to detect and react to different stimuli in its environment
• Differences exist between living and non-living things

Observation: Living vs. Non-Living

• Living organisms respire, need food, and excrete; non-living do not
• Living organisms respond to stimuli vs. non-living do not reproduce or show growth
• Living organisms move at will, while non living things experience no movement at will

Unit 1.2: Cells

• Cells are the smallest functional units in living organisms, and life begins with cells
• Objectives include studying both plant and animal cells and understanding the difference between them
• A cell is defined as the functional unit of a living organism
• Chemical reactions happen inside the cells

Microscopes

• Microscopes are used to view small objects invisible to the naked eye

Hand Lens Microscope

• A hand lens microscope consists of a convex lens attached to a frame with a handle
• Hand lenses have magnification powers, like x2.5 or x5.0
• To use a hand lens, the object must be placed on a flat surface at a short distance from the lens
• Image becomes distinct when the hand lens is moved up and down above the object

Compound Microscope

• A compound microscope has two sets of lenses
  • Eyepiece lens is closer to the eye
  • Objective lens is closer to the object
• Compound microscopes magnify objects at different powers

Using a Compound Microscope

• Position the microscope on a flat surface
• Ensure the microscope is always upright
• Avoid focusing the microscope directly at the sun with one's eye
• Hold the microscope by the handle, supporting the base with the other hand while carrying
• Make sure that eyepiece and objective lenses are clean

Viewing Through a Compound Microscope

• Illuminate objects under a microscope by setting the mirror to direct light through the lenses
• Then place the microscope slide with the object on the stage
• To select an objective lens, twist the revolving nose piece to line it up with the eyepiece
• A clicking sound indicates the lens is locked in place
• Focus with one eye through the eyepiece, by carefully turning the coarse adjustment knob to adjust the distance between the object and the lenses, continuing until the vision is clear
• Begin with a low-powered objective lens when focusing, then use the fine adjustment knob for a sharp image

Observing Onion Cell Structure (Activity 1.3)

• Materials: glass slide, cover slide, dropper, absorbent paper, forceps, iodine solution, shallow container, petri dish, onion bulb, mounted needle, razor blade
• Peel thin inner layer of onion skin using forceps
• Thin piece of onion skin is cut and placed on water drop on glass slide
• The needle covers specimen with coverslip, removing air bubbles
• Add water to the side of the slide and use absorbent paper to remove existing air bubbles
• Put the slide on the microscope for observation

Exercise:

• Observe cells through low/high power lenses and record observations
• Remove the slide, put specimen and leave
• Stains some parts of the cells

Basic Cell Structures Overview

• Cells typically consist of common components despite variance in structure, size, and shape

Cell Organelles

• Cell Organelles are units of a cell that are surrounded by the cell membrane
• Nucleus (Kernel in latin) is the major part of the cells and controls cell activities
• The nucleus contains genetic information in the form of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)
• Nucleus functions like a manager
• Nucleoplasm is contained in the nucleus and it is surrounded by the membrane

Nucleoplasm & Cytoplasm

• Chemical reactions occur within the transparent jelly-like cytoplasm found around the nucleus
• Cytoplasm consists of:
  • Amino acids
  • Mineral salts
  • Glucose
• Water is the primary solvent
• Cytoplasm includes organelles like:
  • Mitochondria
  • Ribosomes
  • Chloroplasts

Cell Membranes

• Cell membranes consist of a thin boundary
• Cell membranes are made up of:
  • Fats
  • Proteins
• Cell membranes are selectively permeable which control movement of substances in and out of the cell

Mitochondria

• Mitochondria measure about one micrometer (1/1000 of a meter)
• Respiration occurs here
• The number of mitochondria per cell depends on chemical activity

Ribosomes

• Ribosomes are in the cytoplasm
• Ribosomes may be on the rough endoplasmic reticulum
• Ribosomes produce proteins

Endoplasmic Reticulum

• The endoplasmic reticulum consists of membrane network which transports materials

Golgi Bodies

• Golgi bodies appear as stacks of vesicles functioning in transport
• These support endo plasmic reticulum

Cell Walls

• Cell Walls only in plant cells
• Cell walls are made up of cellulose to maintain shape and protect inner parts of cell
• Chloroplasts only in plant cells
• Chloroplasts contain chlorophyll which carries photosynthetic pigment
• Vacuoles only in plant cells with few in animal cells
• Vacuoles contain fluids and are surrounded by tonaplasm

Animal and Plant Cell Differences

• Plant cells often contain celluloses
• Animal cells contain cytoplasm and animal cell and plants cell irregular shapes
• Choloroplasts occur in plant cells and animals cells have large and central nucleus
• Animal cells are small in size

Cell Specialization

• Multicellular organisms’ different cells are specialized, giving them diverse structures

Specialized Animal Cells

• Red blood cells: Transport oxygen and carbon dioxide between locations, due to hemoglobin and lacking a nucleus
• Muscle cells: Bring movement through contracting and relaxing, made of contractile fibers, and are spindle-shaped
• Nerve cells: Conduct electric signals because of a long nerve fibre
• Ciliated cells: Trap dust particles in respiratory tract

Specialized White Blood Cells

• The white blood cell is specialized in eating and breaking down bacteria in the body, aiding defense against disease
• Sperm cells have long tails and carry heritable (DNA) factors for propulsion in female sexual organs

Specialized Plant Cells

• Root hair cells: Help intake water and salts, elongated to be very permable
• Palisade cells: Specialize on photosynthesis by containing chlorophyll
• Pholem sieve tubes: Transport food and do not have nucleus to optimize function
• Spongy cells: spherical to allow air flow and photosynthesis.

Unit 1.3: Plant vs. Animal Tissue

• Higher level of biological build up: cells -> tissue -> organ -> system -> organism
• Higher organisms depend on cell structure to function in organisms

Tissue examples in animals:

• Muscle tissue: Made of shaped cells which contract/relax for movement
• Nerve tissues: Electrical impulses transmit from sensory site to action site
• Adipose Tissue: Fat storage that protects from heat loss.

Tissue examples in plants:

• Palisade tissues: For the purpose if photosynthesis that is performed by thin-walled elongation
• Xylem Tissue: The woody tissue the transports water and salts
• Ploem tissue: Tubes that have cell plates at ends and provides food to the body
• Blood and Spongy are other example is tissue

Organs

• Organs are made up of interworking tissue that form a single shape with unified function
  • The stomach, eye, and kidney are examples in animals
  • The leaf and stem are examples in plants.

Systems

• Systems function in realted matters with one another
  • Digestive, endocrine, reproductive, and nervous.

Organisms

• Made of independent systems working.

Organization of Cells

• How cells organize starting with the smallest: cells -> tissue -> organ> system -> organisms
• Part of a cell that is often the outer most layer but very important: membrane
  • Part of a plant cell: made of celluose

Unit 1.4: Diffusion, Osmosis, and The Cell

• Diffusion: Movement of materials from a higher concentrations to a area of low concentration
  • Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
  • This movement is driven by the concentration gradient, the difference in particle concentration between two areas.

Factors Affecting Diffusion

• A higher temperature helps molecules diffuse easier and faster
• A thinner membrane allows diffusion to occur faster
• The concentration gradient will determine rate of molecules/particles diffusion rate
• Smaller particles have a faster diffusion rate
• Moisturized membrane also help

Osmosis

• Defintion: Water passing across a permeable membrane from a concentration to low.
• A semi-permeable membrane allows only certain molecules to pass through, and the concentration of these molecules must be higher
• Osmotic movement is essential to plant/animal

Demonstrations of Diffusions

Two test to check

1. Investigate osmosis in plant tissue Use potato and record data
2. Observe osmosis in animal tissue Use egg and record data

Cell Failure

• If osmosis too high, cells will fail and cause
  • Plasmolysis
  • Lysis
  • Crenantion
• Osmoregulation then controls levels

Unit 1.5:Enzymes

• An enzyme is substance that controls our body processes
• Metabolism: all chemical reactions in our body
• Catabolism: breaking down larger units
• Anabolism: Building of the smaller units with the broken ones
• Objectives: Explain enzymes, discuss features, and discuss applications

Enzymes: General overview

• Enzymen are biological catalysts
• Catalysis: Controls rate of reaction and don't change
• Enzymes are only organic substances and not living things

Characteristics of Enzymes:

• Features:
  • protiens
  • temperature-sensitive
  • pH-Sensitive
  • Enzymes are specific
• Enzymes break down in forward way

Saliva and Amylase

• Amylase helps break down strach to enzymes
• A proper test environment needed Caution: Careful on sharing because it leads to harm
• Test saliva and compare effects

Enzyme Classification and Application

• Two types of Classification for enzymes 1) Intracellular enzymes 2) Extracelluar enzymes
• Science has expanded the uses of enzymes
  • Breaking down stains and tanning animals

Unit 1.6: Classification

• To describe types using closeness in relationships Main objective: Sort types and describe based on their nature
• Many organisms are put a group and organized Classification- How organ respond using group

Classification of Organisms

• Biological classification
• A natural classification
• arranged organisms in kingdom
• Five kingdoms: animal, plant, fungi protista and moneran

Kingdom:

• Animalia or Animal Kingdom
• Eukaryotic and hetero -Porifera
  • Coelenterata
  • Platythel -minhdes
  • Nematoda -Mollusca -Arthropoda -Chordata -Echinoderntata
• Plantae: Consist of green tissue and chlorophyll
• Fungi; fungi make food. Eukaryotic and heterotroph - mushroom, yeast
• Monera are not defined as plants or cells as eg
  • algae and protozoa

System:

• In general they are not categorized

Biological names

• Based on regions of world - Use Binomina - The scientists will then provide name -Use leaf key and soil worms

UNIT 2.0: NUTRITION

• Includes both animals and plants
• Contains nutrients in our foods with 7 keys
  • Carbohydrates
  • protiens
  • fats
  • vitamins
  • mineral
  • water
  • roughage
• Carbohydrates: carbon , hydro, and oxygen
  • from kilo 16 Use for Body

Carbo groups:

1. monosaccharides: form carb
2. disacchairdes : mixed
3. poly: chain

protiens:

Also key mix of elements

• Amino acid
• peptides of amino acid = amide There are amino

What are lipids?

• Similar to cab and consist units
• Also called fats

What our the uses of fats?

Key to membranes

• source of energy
• store vits
• Protect nerve cells

Vitamin: are org matter

How can vitamin be beneficial to our bodys?

• Some are retina
• helps make you see Vitamin C Some helps tissues

Key element

• Calcium
• Iron also called fe
• water as solvent Water for us = 3/4 of what we are

Roughage

• rough like corn
• stimulates body Body Test
• Test food to find Iodine
• starch with iodine Test sugar:

UNIT 2.3 - Animal Nutrition

• Holozioc: digestion of protiens and animals
• holozoic feeding complex molecules being feed to body
• Terms definition:

1. Ingest;Take molecules in body
2. Digestion- Breaks down
3. Absortion- molecules take
4. Egestion Removes unused

Body canal

: A tube

• General work makes food To cnal we carry: mouth oesophagues Stomach Duodenem Small/large intestine Rectum and anus

Digestion Types

• First type is physical and the second type is chemical -Physical is starts at the mouth to the intes
• Chemical digestion occurs when salvation is released

Enzyme:

• Converts food in mouth to: > salava produces enzyme Water
• water is solvent and digestor for reactions Swallowing is the shaping of food and the oseaphigus leads to the perstals

Digestion in Stomoach

• The body is made to litres
• stomach release juice which is stomach juice
• HCI releases
• acid break down for digest

Chemical reaction in Small Intes

Duo/Ite

Absorption of dig

Ite can directly absorb these The colon are then water absorb

• What in Feaces:
• Undigh
• Dead and celulol

Main functions

• Livers filters waste Make glucose more storag
• Deamint: amino change structur

UNit 2.4 Plant

• Descirbe photosyn
• Describe rhozious to show food.
• photo means like and sunsynthesis
• carbon + plus h20 make food

2 Stage

• Stage one: Light - Chlorophy absorbs and water spit to hydrogen
• SecondStage
  • Hydrogen will meet C combine to form glucode

Tests for all elements

• Sun, Cholorophyll
• Also needs like for photo

Vascular Bundles

• tissue transport aterial and minerals

Leta Adaptaiton- Leaves

Large And other featurs

Saprophytic nutrition

• Plants need for growth

Ruziphorous

• Fungi
• Need all to gort

Dig in Rhozopiud

Rhizoids

• and Hypha
• also to gort