Human Biology

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Human Biology by Mind Map: Human Biology

1. Microscopes

1.1. Calculating magnification

1.1.1. multiply magnification of objective lens with magnification of ocular lens

1.2. FOV

1.2.1. diameter of circle view when looking down a microscope

1.2.2. higher the magnification, smaller the FOV

1.2.3. calculate intial FOV

1.2.3.1. use tiny ruler

1.2.3.2. grid slide

1.3. Diagram of microscope

2. Cells

2.1. organelles

2.1.1. specialised structure, surrounded by its own membrane and perform specific function

2.1.2. examples

2.1.2.1. nucleus

2.1.2.2. Endoplasmic Reticulum

2.1.2.3. Chloroplast

2.1.2.4. Centrioles

2.1.2.5. Mitochondria

2.1.2.6. Vacuoles

2.1.2.7. Lysosome

2.1.2.8. Ribosome

2.1.2.9. Golgi Apparatus

2.2. non-organelles

2.2.1. cell membrane

2.2.2. Cytoplasm

2.2.3. cell wall

2.2.4. cytoskeleton

2.2.4.1. framework of protein fibres that gives cell its shape

2.2.4.2. assists in cell movement

2.2.4.3. consists of

2.2.4.3.1. microtubules

2.2.4.3.2. microfilaments

2.3. multi-cellular organism

2.3.1. can feed, excrete

2.3.2. repsire

2.3.3. respond to stimuli

2.3.4. reporudce, grow

2.4. Unicellular orgainsm

2.4.1. consists of one single cell

2.5. inclusions

2.5.1. chemical substances that are not part of the cell structure but found in cytoplasm

2.5.2. red pigment = haemoglobin

2.5.3. melanin pigment in skin, hair

2.6. cells are small

2.6.1. small cell has larger SA to volume ratio than large cell

2.6.1.1. larger SA = easier for particles to enter and leave celll

2.6.1.2. small volume = easier for organelles to reach one place from the other

3. Enzymes

3.1. metabolism

3.1.1. all chemical reactions that take place in cell

3.1.2. types

3.1.2.1. catabolism

3.1.2.1.1. reactions in which large molecules broken down into smaller ones

3.1.2.1.2. releases energy

3.1.2.2. anabolism

3.1.2.2.1. small molecules built into larger molecules

3.1.2.2.2. uses energy

3.2. importance

3.2.1. allow chem reactions to take place at body temp

3.2.2. without them- reaction proceed to slow

3.3. Specific

3.3.1. only combine with one particular subtrate

3.3.1.1. one specific chem reaction

3.4. factors

3.4.1. termperature

3.4.1.1. optimum temp

3.4.1.1.1. enzyme works best and effiicient at temp 30-35

3.4.2. Enzyme concentration

3.4.2.1. more concentrate = fast rate of chem reaction

3.4.3. Subtrate concentration

3.4.3.1. more concentrate= faster rate

3.4.4. Products of reaction must be constantly removed

3.4.4.1. or rate of reaction will slow

3.4.4.1.1. harder for subtrate mol to be in contact with enzyme mol

3.4.5. PH levels

3.4.5.1. each enzyme has optimum PH which help make more efficient

3.4.6. presence of co- factors/ co-enzymes

3.4.6.1. co-factors

3.4.6.1.1. change shape of active site so enzyme can combine with subtrate

3.4.6.1.2. certain ion

3.4.6.2. co-enzyme

3.4.6.2.1. non-protein organic molecules

3.4.6.3. most enzyme require co-factor before catalysing reaction

3.4.7. enzyme inhibitors

3.4.7.1. substances slow or stop enzyme activity

3.4.7.2. control reactions = produce products in specific amounts

3.4.7.3. penicillin inhibits enzyme in bacteria that is involved in construction of cell wall

4. Tissues

4.1. level of structural organisation

4.1.1. cell - tissues - organs - system - organism

4.2. a group of cells that are simillar in structure that work together to carry out a specific task

4.3. 4 types

4.3.1. epithelial tissue

4.3.1.1. covering or lining tissue

4.3.1.2. closely joined together

4.3.1.3. vary in shape

4.3.1.4. outer layer of skin

4.3.1.5. covering and inner lining of heart

4.3.1.6. kidneys, heart, stomach, hollow organs made up of epithelium

4.3.2. connective

4.3.2.1. provides support for body

4.3.2.2. holds all body parts together

4.3.2.3. cells not close together, separated by matrix

4.3.2.3.1. large amounts of material that is not made up of cells

4.3.2.4. bone, cartilage, tendons, ligaments, blood

4.3.3. muscular

4.3.3.1. cells are long and thin = muscle fibres

4.3.3.2. 3 types

4.3.3.2.1. skeletal

4.3.3.2.2. involuntary

4.3.3.2.3. cardiac

4.3.4. nervous

4.3.4.1. made up of specialised nerve cells (neurons)

4.3.4.2. neurons consists of long projections from the body of the cell

4.3.4.3. when neuron stimulated = messages carried along these projections from one part of the body to the other

4.3.4.4. nervous tissue found in brain, spinal cord, nerves

5. cell transport

5.1. 2 types of cell transport

5.1.1. Passive transport

5.1.1.1. cell does not use energy

5.1.1.2. Examples

5.1.1.2.1. Diffusion

5.1.1.2.2. Osmosis

5.1.1.2.3. carrier mediated transport- Facilitated Diffusion

5.1.2. Active transport

5.1.2.1. Uses energy

5.1.2.2. Examples

5.1.2.2.1. carrier mediated transport- Protein pumps

5.1.2.2.2. Vesicular transport

5.2. cell membrane

5.2.1. Plasma membrane

5.2.1.1. double layer of phospholipids

5.2.1.2. proteins floating in this layer

5.2.1.3. function

5.2.1.3.1. control entry and exit

5.2.1.3.2. seperate cell from neighbouring cells

5.3. homeostasis

5.3.1. body systems work together to make sure that cellular environment is kept constant

5.4. fluid mosaic model

5.4.1. cell membrane structure

5.4.2. 'fluid' = molecules that make up model are constantly changing position

5.4.3. 'mosaic' = all different kinds of molecules

6. Circulatory system

6.1. main internal transport system

6.2. link between cells inside body (require certain requirements) and environment outside body (supplies requirements)

6.3. special organs

6.3.1. extract requirements from environment

6.3.1.1. Digestive system = absorb nutrients

6.3.1.2. respiratory system= absorb oxygen

6.3.2. pass waste from body to environment

6.3.2.1. respiratory system = excrete CO2

6.3.2.2. Kidneys = excrete wastes

6.4. Blood

6.4.1. Transport link between cells of all the body

6.4.2. Functions

6.4.2.1. Transport O2, nutrients to all cells of body

6.4.2.2. transport CO2, other wastes products away from cells

6.4.2.3. Transport hormones to cells

6.4.2.4. maintain PH of body fluids

6.4.2.5. Distribute heat = maintain body temp

6.4.2.6. maintain water content, ion concentration of body fluids

6.4.2.7. protect against disease-causing micro-organisms

6.4.2.8. prevent blood loss = clotting when vessels damaged

6.4.3. Made of...

6.4.3.1. plasma

6.4.3.1.1. liquid part

6.4.3.1.2. 55% of blood volume

6.4.3.1.3. 91% H20

6.4.3.1.4. rest made of dissolved substances

6.4.3.2. formed elements

6.4.3.2.1. cells or cell fragments

6.4.3.2.2. 45% of blood volume

6.4.3.2.3. red blood cells (erythrocytes)

6.4.3.2.4. white blood cells (leucocytes)

6.4.3.2.5. platelets (thrombocytes)

6.5. transport of oxygen

6.5.1. 3% O2 in blood plasma

6.5.2. 97% in combination with haemoglobin molecules (red blood cells)

6.5.2.1. haemoglobin + oxygen = oxyhaemoglobin

6.5.2.1.1. Hb + O2 = HbO2

6.5.2.1.2. easily broken down to release oxygen

6.5.2.2. when O2 concentration high

6.5.2.2.1. O2 + Hb

6.5.2.2.2. occur in capillaries of lungs

6.5.2.2.3. O2 diffuses into blood from air in air sacs

6.5.2.3. when O2 concentration low

6.5.2.3.1. HbO2 = Hb + O2

6.5.2.3.2. tissue fluid around cells = low O2 concentration as cells continuously use O2

6.5.2.3.3. while flowing through capillaries between cells, red blood cells give up O2, = O2 diffuses into tissue fluid = into cell

6.6. transport of CO2

6.6.1. 3% dissolved in plasma

6.6.2. 22% as carbominohaemoglobin

6.6.2.1. combines with globin part of haemoglobin

6.6.3. 70% as bicarbonate ions

6.6.3.1. CO2 react with H20 = H2CO3 = dissociates into hydrogen ion, bicarbonate ions

6.6.4. as blood flows through capillaries between body cells, CO2 dissolves in plasma = difference in CO2 concentration

6.6.5. In alveoli (air sacs of lungs), surrounded by dense network of capillaries

6.6.5.1. CO2 dissolved in plasma = diffuses out of blood, into air in alveolus

6.6.5.2. carbominohaemoglobin breaks down = CO2 mol released, diffuses into alveolus

6.6.5.3. H ions + bicarbonate ions = form H2CO3 acid = break down under enzyme action = H20 +CO2

6.6.5.3.1. CO2 diffuses into alveolus

6.6.6. CO2 + H20 = H2CO3 = hydrogen ions + bicarbonate ions

6.7. transport of nutrients/ wastes

6.7.1. transported and dissolved in plasma

6.7.2. 4 organic nutrients

6.7.2.1. glucose

6.7.2.2. vitamins

6.7.2.3. amino acids

6.7.2.4. fatty acids / glycerol

6.7.3. 4 important ions (inorganic nutrients)

6.7.3.1. sodium ions

6.7.3.2. calcium

6.7.3.3. pottasium

6.7.3.4. chloride/ iodide

6.7.4. 3 organic wastes

6.7.4.1. urea

6.7.4.2. creatinine

6.7.4.3. urea acid

6.7.4.4. CO2

6.8. blood vessels

6.8.1. arteries

6.8.1.1. carry blood away from heart

6.8.1.2. walls smooth/eastic

6.8.1.3. divide into smaller arteries (arterioles)

6.8.1.4. arteries

6.8.1.4.1. muscles contract, reduce diameter of artery, thus, blood flow to an organ (vasoconstriction)

6.8.1.4.2. Muscle relax = increase diameter of artery = increase blood flow to organ (vasodilation)

6.8.2. capillaries

6.8.2.1. microscopic blood vessels

6.8.2.2. form network that can reach every cell

6.8.2.3. one layer of cell = easy access to surrounding cell

6.8.3. veins

6.8.3.1. carry blood back to body

6.8.3.2. no muscular walls

6.8.3.3. low blood pressure, have valves to prevent back flow

6.8.3.4. divide into smaller veins = venules

6.8.4. when exercise

6.8.4.1. cell respire = more for energy

6.8.4.2. respiration in muscle cell create wastes = CO2 and lactic acid

6.8.4.3. act as vasodilators = increase blood flow = ensure cells supplied with O2 ad nutrients

6.8.4.4. heat released increase blood temperature, increase heart rate

7. Excretery System

7.1. Removal of wastes of metabolism from body

7.2. 4 organs involved in processing and excreting wastes

7.2.1. Lungs

7.2.1.1. Excrete CO2 from body from cells

7.2.2. Liver

7.2.2.1. Process many substances so can be excreted

7.2.2.1.1. detoxifies alcohol/ drugs

7.2.2.1.2. breaks down haemoglobin to bile pigments

7.2.2.1.3. deactivates hormones

7.2.2.2. proteins

7.2.2.2.1. used extensively in body

7.2.2.2.2. built up from amino acids

7.2.2.2.3. used for cell structures, enzymes, antibodies and grandular secretion

7.2.2.2.4. very little is used in energy-releasing processes as long sufficient supply of carbohydrate/ fats

7.2.2.2.5. view protein structure

7.2.2.3. deamination

7.2.2.3.1. process of metabolising proteins to form carbohydrates

7.2.2.3.2. occurs if other energy sources used up

7.2.2.3.3. process = remove amino group (NH2) from amino acid (view diagram)

7.2.2.3.4. because amino group (NH2) converted to Ammonia (NH3) in liver (wastes)

7.2.3. Sweat Glands

7.2.3.1. lower layers of skin

7.2.3.2. Secrete sweat

7.2.3.2.1. largely water = for cooling (500 ML of water/sweat/ some drugs a day)

7.2.3.2.2. by products of metabolism = salts, urea, lactic acid

7.2.3.3. How?

7.2.3.3.1. duct carries sweat from sweat glands

7.2.3.3.2. cells surrounding glands = squeeze sweat to skin surface

7.2.3.4. view diagram

7.2.4. Kidneys

7.2.4.1. principle excretory system organs

7.2.4.2. maintain constant concentration of materials in body fluids

7.2.4.3. remove toxic wastes

7.2.4.3.1. nitrogenous wastes urea

7.2.4.3.2. uric acid

7.2.4.3.3. creatinine

7.2.4.4. review diagram

7.2.4.5. microscopic structure of kidney

7.2.4.5.1. nephron

7.2.4.5.2. urine formation

8. New Topic

9. Reproduction cycles & fertillisation

9.1. Ovarian Cycle

9.1.1. Begin at Puberty (11-14) End at menopause (40-45)

9.1.2. The cyclic changes within ovaries (28 days)

9.1.3. 3 stages

9.1.3.1. Ovulation (13-15)

9.1.3.1.1. mature follicle bursts= expels egg

9.1.3.1.2. egg swept into fallopian tubes by current (beating cilia within funnel)

9.1.3.2. Luteal phase (15-28)

9.1.3.2.1. once egg expelled = follicle collapses

9.1.3.2.2. blood within= form clots = absorbed by remaining follicle cells= corpus leteum

9.1.3.2.3. corpus luteum = secretes hormones (unfluence uterine lining)

9.1.3.2.4. 2 alternate endings

9.1.3.3. New Topic

9.2. Menstrual cycle

9.2.1. cyclic changes occuring in ovaries, where the changes in the endometrium are associated with stages in ovarian cycle

9.2.2. endometrium changes = to prepare for developing embryo (egg released at ovulation is fertillised)

9.2.3. stages- view diagram

9.3. sexual intercourse

9.3.1. in order to take place

9.3.1.1. sperm must be deposited in vagina

9.3.1.2. penis must be enlarged and firm (erection)

9.3.1.3. ejaculation must occur, can be accompanied with orgasm

9.3.1.3.1. sexual stimulation of penis = rhythmic contractions of epididymis, vasa deferentia, seminal vesicles, prostate glands propel contents of ducts and glands into urethra then out of body (3ml of semen/250-300mil sperm)

9.3.1.4. female sexually stimulated

9.3.1.4.1. blood fills erectile tissue near vaginal opening = reduce size of vaginal opening = increase stimulation of penis

9.3.1.4.2. arousal = copious secretion of mucus by glands near cervix = lubrication of epithelial lining of vagina = easy entry of penis

9.4. Fertilisation

9.4.1. male ejaculate = sperm released in vagina at entrance to the uterus ( insemination)

9.4.2. Sperm travel through cervix - body of uterus - uterine tubes

9.4.3. - upper portion of uterine tubes reached often within few minutes ( swimming motion of sperm / muscular contraction of uterus & uterine tubes

9.4.4. sperm mortality high = few thousands make out of millions make it to uterine tubes

9.4.5. since ovulation, muscular contraction of uterine tube & beating action of cilia have been transporting egg towards uterus. (fertellisation normally occur in uterine tubes, when egg 1/3 way down tube. )

9.4.6. mature egg surrounded by layer of follicle cells = corona radiata

9.4.7. acid hold cells of corona radiata together= can be loosened = thousands of sperms containing enzymnes on tip surround egg

9.4.8. entrance of 1 sperm into egg = stimulate formation of fertilisation membrane around egg = prevent entrance of anymore sperm

9.4.9. once sperm enter egg = tail absorbed, head move through cytoplasm of egg in form of male pronucleus

9.4.10. entrance of sperm = stimulate secondary oocyte to complete meiosis 2

9.4.11. nucleus of egg develop into female pronucleus = fuse with male pronucleus = form single nucleus = diploid number of chromosomes (zygote) = fertilisation complete

10. Follicular Phase (0-13)

10.1. development of the follicle

10.2. puberty begins = cells forming wall of primary follicle enlarge & divide = create layer of cells around egg

10.3. cell secrete = create fluid filled space around follicular cells = force egg to edge of follicle (secondary follicle)

10.4. fluid cavity continue growing = follicle enlarge = pushes way to ovary surface = mature follicle

11. scientific inquiry

11.1. ask a question

11.1.1. Begins with problem.

11.1.2. Scientists try to find solution for that problem

11.2. Do background research

11.2.1. review of books

11.2.2. scientific journals

11.2.3. Google/Internet

11.3. construct hypothesis

11.3.1. tentative proposal made to explain certain observations

11.3.2. Often make a prediction based on hypothesis (using if-then reasoning)

11.3.3. a statement

11.3.4. short

11.3.5. single idea that can be tested

11.3.6. links 2 variables and states relationship between them

11.4. Test with an experiment

11.4.1. Prediction based on hypothesis

11.4.2. Variable

11.4.2.1. independant variable

11.4.2.1.1. factor that is being investigated

11.4.2.1.2. deliberately changed to determine its effect

11.4.2.2. dependant variable

11.4.2.2.1. observation or results of the changes made by independant variable

11.4.2.3. controlled variable

11.4.2.3.1. factors kept the same for both control and experimental groups

11.4.2.4. uncontrolled variable

11.4.2.4.1. variables that are not kept the same for control and experimental groups

11.4.2.4.2. overlooked or impossible to control

11.4.3. Repitition

11.4.3.1. Doing same experiment many times

11.4.3.2. Performing experiments on larger sample size

11.4.3.3. Test reliability

11.4.4. Placebos

11.4.4.1. inactive substance that looks like real medications

11.4.4.2. In forms of pills, tablets, injections, mock-surgery

11.4.4.3. One group (control group) gets placebos which looks identical

11.4.4.4. if difference between 2 groups clear

11.4.4.4.1. drug is effective

11.5. Analyse results and draw conclusion

11.5.1. data collected in forms of

11.5.1.1. table

11.5.1.1.1. organised

11.5.1.2. graphs

11.5.1.2.1. easy to see trends

11.5.1.3. bar or column graphs/histograms

11.5.1.3.1. when there are many categories

11.5.1.4. quantitative data

11.5.1.4.1. can be measured

11.5.1.4.2. length, height, area, volume, weight

11.5.1.5. qualitative data

11.5.1.5.1. observed, not measured

11.5.1.5.2. colours, textures, smells tastes

11.5.1.5.3. appearance, beauty

11.6. Conclude hypothesis

11.6.1. TRUE

11.6.2. FALSE

11.7. Report results for peer review

12. Cellular Respiration

12.1. energy goes to..

12.1.1. 60%

12.1.1.1. heat to keep body at const. temp. (homeostasis)

12.1.2. 40%

12.1.2.1. used to form ATP (adenosine triphosphate)

12.1.2.1.1. energy required for...

12.1.2.1.2. formation of ATP

12.2. C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy

12.3. 20 seperate reactions in series needed (with help of enzymnes) to control release of energy

12.4. 2 types

12.4.1. anerobic

12.4.1.1. occurs in cytoplasm

12.4.1.1.1. enzymes for anaerobic r.

12.4.1.2. breakdown of glucose without oxygen

12.4.1.3. no oxygen available = 2 mol of pyruvic acid = 2 lactic acids

12.4.1.4. during vigorous exercising, oxygen unable to supply enough O2 to energy demands of contractin muscles ,= anaerobic r. supplies extra energy

12.4.1.4.1. result - accumulation of lactic acids in muscles (muscle pain)

12.4.1.5. lactic acid then taken by blood to liver = combine with O2 to form glucose then glycolygen

12.4.2. aerobic

12.4.2.1. occurs in mitochondria

12.4.2.2. inner membrane of mitochondria has enzymes needed for 20 reactions to breakdown glucose in cellular respiration

12.4.2.2.1. inner membrane of mitochondria is folded = karge SA for reaction to take place

12.4.2.3. pyruvic acids = broken down to CO2 and H20

12.4.2.3.1. enzymes in mitochondria = 2 more series of reactions to occur

13. circulatory system

13.1. body's main internal transport system

13.2. link between cells inside body and environment outside body

13.3. blood

13.3.1. transport link between all cells in body

13.3.2. functions

13.3.2.1. transport oxygen and nutrients to cells

13.3.2.2. transport CO2 and other wastes products away from cells

13.3.2.3. maintain PH of body fluids

13.3.2.4. maintain body temp = distribute heat

13.3.2.5. maintain water content, ion concentration of body fluid

13.3.2.6. protect against disease-causing micro-organisms

13.3.2.7. clotting when vessels damaged

13.3.3. consists of

13.3.3.1. 55% plasma (liquid)

13.3.3.1.1. 91% water

13.3.3.1.2. rest made up of dissolved substances (nutrients, ions, gases, hormones, proteins, wastes

13.3.3.2. 45% formed elements (non-liquid), (cell and cell fragments)

13.3.3.2.1. white blood cells (leucocytes)

13.3.3.2.2. red blood cells (erythrocytes)

13.3.3.2.3. platelets (thrombocytes)

13.4. special organs needed to extract requirements from environment

13.4.1. respiratory system

13.4.1.1. absorb oxygen

13.4.2. digestive system

13.4.2.1. absorb protein

13.5. Other organs pass waste from body to environment

13.5.1. respiratory system

13.5.1.1. excretes CO2

13.5.2. digestive system

13.5.2.1. kidneys excrete wastes

14. DNA

14.1. DNA= deoxyribonucleic acid

14.2. molecule strucuture

14.2.1. in form of long strands

14.2.1.1. length 2-3m

14.2.1.2. width 1/2000000th of mm

14.2.2. long mol can fit in small nucleus space

14.2.2.1. DNA strand coiled around histones

14.2.3. if cell not dividing

14.2.3.1. coiled DNA forms tangled network =chromatin

14.2.4. if cell dividing

14.2.4.1. must keep DNA intact during cell division

14.2.4.2. chromatin become chromosomes

14.2.4.2.1. coiled chromatin becomes even more tightly coiled = chromosomes (can be seen with light microscope)

14.3. DNA strucuture

14.3.1. double helix

14.3.2. nucelotide

14.3.2.1. each phosphate group and sugar molecule with a nitrogen base

14.3.2.2. units making up DNA molecule

14.3.3. 4 nitrogen bases

14.3.3.1. adenosine - thymine

14.3.3.2. cytosine - guanine

14.3.3.3. weak hydrogen bond between base pairs

14.3.4. view diagram

14.4. Replication of DNA

14.4.1. undergoing process between cell division.

14.4.2. results in formation fo new DNA mol tht are identical = form exact replicas of themselves

14.4.3. process

14.4.3.1. 2 linked chains of DNA mol seperate

14.4.3.2. easy = weak hydrogen bond between bases

14.4.3.3. each seperated section = contain half original info= serve as templates for nucleotides tht will form other new half ( A-T, C-G)

14.5. Role of DNA

14.6. nuclei of human cell

14.6.1. 46 DNA mol

14.6.2. DNA mol contain genes

14.6.2.1. section of mol

14.6.2.2. contain genetic code

14.6.2.3. determine structure & activities of cell

15. Digestive System

15.1. extracts nutrients from food we eat and absorbs them into body for use by cells

15.2. Digestion is process in which carbohydrate, protein and fat mol broken down to products small enough to be absorbed by cells.

15.3. Organs specially structured and arranged = carry out 6 activities

15.3.1. ingestion of food and water

15.3.2. mechanical digestion of food

15.3.3. chemical digestion of food

15.3.4. movement of food along alimentary canal

15.3.5. absorption of digested food and water into blood and lymph

15.3.6. elimination of material that is not absorbed

15.4. Alimentary canal = continuous tube tht runs from mouth to anus

15.5. Study worksheet

15.6. Diagram of villi

15.7. Diet

15.7.1. Affects absorption in alimentary canal

15.7.2. speed of material moving through alimentary canal

15.7.2.1. Size and contents of meal

15.7.3. Material pushed into small intestines more quickly

15.7.3.1. large meal (causes greater stretching of stomach)

15.7.4. Process is slow of movement from stomach to small intestine

15.7.4.1. Consume high protein, high fat content

15.7.5. Alcohol/ caffeine stimulate movements in stomach

15.8. Illnesses

15.8.1. Constipation

15.8.1.1. movements of large intestines reduced, contents remain there too long

15.8.1.2. water is absorbed = faeces become drier, harder than usual

15.8.1.3. Defecation becomes difficult/ painful

15.8.1.4. Due to lack of roughage in diet (cellulose/ insoluble fibre. lack of exercise, emotional problems

15.8.1.4.1. Roughage stimulates movement of alimentary canals

15.8.2. Diarrhoea

15.8.2.1. frequent defecations of watery faeces

15.8.2.2. Due to irritation of small/large intestines = (caused by bacterial or viral infection)

15.8.2.3. Increases peristalsis = contents move through intestines too fast = not enough water absorption

15.8.3. Bowel Cancer

15.8.3.1. uncontrolled growth of cells of walls of large intestines

15.8.3.2. unbalanced diet (high consumption of red and processed meat and low consumption offibre

15.8.3.3. high alcohol consumption/ smoking

15.8.3.4. Overweight, obese, physical inactivity

15.8.4. Coeliac disease

15.8.4.1. cannot tolerate gluten

15.8.4.2. gluten = wheat, rye, barley

15.8.4.3. if eaten= immune system responds = damaging / destroying villi in small intestines

15.8.4.4. Therefore, nutrients can't be absorbed

15.8.4.5. Inherited, symptoms : muscle cramps, joint pain, leg tingling

15.8.5. Importance soluble fibre

15.8.5.1. Sources : fruits, vegetables, soy, barley products

15.8.5.2. Links to low cholesterol in blood

15.8.5.3. decrease = risk of heart diseases, cancer

15.8.5.4. benefit effect on glucose levels

15.8.5.5. fats in intestines trapped by soluble fibre = prevent their absorption by the body

16. Production of sex cells

16.1. production of sperm/egg

16.1.1. reproductive systems specialise for production of male/female sex cells (gametes)

16.1.2. gametogenesis

16.1.2.1. meiosis results in half chromosome-new cells, developing into gametes (sperm or egg)

16.1.2.2. 2 types

16.1.2.2.1. spermatogenesis

16.1.2.2.2. oogensis

16.1.3. male (spermatozoon) & female (ovum) gametes fuse together at fertilisation = form zygote

16.1.3.1. gametes = have only half the chromosome number of body cells (meiosis)

16.1.4. from zygote = multicelled organism develop

17. New Topic

18. New Topic