Presentation on theme: "GROWTH PATTERNS a) sigmoid growth curve ( organism and population )"— Presentation transcript:
1 GROWTH PATTERNS a) sigmoid growth curve ( organism and population ) b) human growth curvec) limited growth curve ( annual plants ) and unlimitedgrowth curve ( perennial plants )d) isometric growth ( fish ) and allometric growth( human organs )e) intermittent growth curve ( arthropods )
2 By the end of the lesson the students should be able to: 22.3 Types of Growth CurvesObjectives1By the end of the lesson the students should be able to:give the types of growth curvesdescribe the types of growth curvesgive the example of organisms which growth pattern follow the growth curves
3 Organism that have a sigmoid growth curve are:- Growth patternsSigmoid Growth Curves2Organism that have a sigmoid growth curve are:-Individual organism / large size of multi cell plants / animalsMicroorganisms population ( yeast, bacteria )3
5 Intermittent growth curve Growth PatternsThe Patterns1patterns of growth vary from species to speciesthe patterns of growth in living multicellular organisms are:human growth curvevs.allometricisometriclimitedunlimitedvs.Intermittent growth curve
7 Growth patternsHuman Growth Curves2In human, the growth curve after birth appears to consist of two sigmoid curves, with two main rapid growth phases, the infant phase and the adolescent phase.A slower growth phase is known as the childhood phase can be found in between these two rapid growth phases.
14 Growth patterns Infant phase: Human Growth Curves 8Infant phase:Very rapid growth rateIrrespective in both male or female babies.
15 Growth patterns 2. Childhood phase : growth rate is slower. Human Growth Curves92. Childhood phase :growth rate is slower.beginning at the age of four,the rate is slightly higher in boys than in girls
16 i.e. two years earlier than begins in males. Growth patternsHuman Growth Curves3. Adolescent phase:10growth rate is rapid.in the earlier part of this growth phase, females demonstrate a more rapid growth ratei.e. two years earlier than begins in males.
17 Growth patterns 3. Adolescent phase: Human Growth Curves 11At the later part of this growth phase, the male growth rate becomes higher than the female growth rate.This difference results in the females attaining puberty at an earlier age compared to males.Females attain puberty around the age of 12, while males attain puberty when they are about 14 years old.
18 most individuals would have attained maturity. Growth patternsHuman Growth Curves124. Adult phase:growth rate is zeromost individuals would have attained maturity.Males achieve this phase at the age about 18 while females at the age around 16.
19 growth rate is negative Growth patternsHuman Growth Curves135. Ageing phasegrowth rate is negativei.e. the body proportion will start to decrease starting from the age of 30.
21 Relative short life span Growth patternsLimited Growth Curves14The growth of an organism to a maximum fixed size, which depends on the type of the organism.Relative short life span
22 Growth patterns A single Sigmoid growth shape Limited Growth Curves 14Growth is complete when the organism achieves its maximum size.and then demonstrates the negative growth, senescenceA single Sigmoid growth shape
23 Growth patterns e.g. most plants and animals, including human Limited Growth Curves15e.g. most plants and animals, including human
25 Growth patternsLimited Growth Curves16In annual plants, the sigmoid growth curve of dry mass versus time shows a small reduction in dry mass in the initial part of growth, due to seed germination.During germination, food stored in the cotyledons is usually used up before the first leaves undergo photosynthesis.
26 Growth patterns Limited Growth Curves 18This loss of mass is later replaced when the first leaves develop and start photosynthesis.Later, growth rate is very rapid, until it becomes constant at a later stage.This rapid growth rate is maintained until the plant achieves maturity, after which the rate gradually reduces until it becomes zero.e.g: pea plant
27 Growth patterns Unlimited Growth Curves 19Refer to non-stop growth over a relatively long life spanExample organisms demonstrate unlimited growth:Obelia colonies,coral reefs andmultiple season woody trees
28 Growth patternsUnlimited Growth Curves19The growth curve for unlimited growth comprises a series of small sigmoid curves.This type of curve shows that there is an increase in the mass and size every season.
29 Growth patternsUnlimited Growth Curves20In plants that demonstrate unlimited growth, there is no fixed rate and the growth continues until enemies, natural catastrophe or diseases cause destructive effects on them.
32 Growth PatternsAllometric Growth23Allo= Gk. differentThe growth of an organism within which different organs grow at different rates from each other and from the overall growth.involves the change in size and externalshape/ features of the organism
33 Growth Patterns involves the change in size and external Allometric Growth23Allo= Gk. differentinvolves the change in size and externalshape/ features of the organism
34 Growth Patterns Allometric Growth 24It shows the correlation between the growth and development of the organisme.g. in mammals: the growth rates of the lymphatic and reproductive tissues is differenti.e. the growth rates of both tissues are the highest at the different stages of development
35 Growth PatternsAllometric Growth25the mammalian lymphatic tissues grows rapidly during the early childhood yearsbut during adolescence its growth rate is lower, why?the mammalian reproductive tissues grows faster during the stage of adolescence, why?
36 This is because lymphoid tissues are required by a young individual to give it natural immunity and defense againtsdisease.This function is less needed during the adult phase.The reproductive system only starts to grow anddevelop during the adolescent phase.Similarly, in embryos, the brain and the head will bothstart growth and development together in the earlyphase of life, while the complete development of handsand feet only occurs in the later phase.
39 Growth Patterns Isometric Growth 29The growth of an organism within the organs grow at the same rates with the other parts of the body.the relative size of the organs is constanti.e. the size of the organs increase, but the external features remain the samee.g. fish, grasshoppers, cockroaches
40 Growth Patterns Isometric Growth 30not accompanied by a change in shape of the organism40
41 Growth Patterns e.g. in grasshoppers Isometric Growth 31e.g. in grasshoppersthe relative proportion of the organs and whole body (size and shape remain the same
42 Growth PatternsIsometric Growth32e.g. in a cucumber leaf
43 Intermittent Growth Curve Growth Patterns33Intermittent Growth CurveIt is a discontinuous growth occurs in insects & other arthropods metamorphosis.Growth is limited by the hard exoskeleton during certain periods until the ecdysis / moulting process takes place.Then, growth occurs very suddenly at a rapid pace.(rate of movement)Produces a step-like (intermittant) growth curve.Each stage in between ecdysis is known as instar.43
45 Intermittent Growth Curve Growth Patterns35Intermittent Growth CurveEcdysis:also known as moultinga process of changing the old exoskeleton of arthropods replaced with new soft layer and later becomes harden again.occur periodically to allow growth and development.during ecdysis, arthropod breathes in a lot of air- body expands and break the old exoskeleton45
46 Intermittent Growth Curve Growth Patterns36Intermittent Growth CurveEcdysis:when old exoskeleton is removed,arthropod once again breathing in more air to increase it size beforenewly formed layer of chitinious exoskeleton hardens.
49 two types: complete and incomplete Growth Patterns38Intermittent Growth CurveMetamorphosis: Definitiona process of changing in shape which occur from one stage to the following stage in animals (insect).two types: complete and incompletecomplete metamorphosis occur in holometabolic insects e.g. housefly, butterflyincomplete metamorphosis occur in hemimetabolic insects e.g. cockroach grasshopper49