COEPULATION IN RANA This takes place during rainy season. The female frog sings to attract the male. The male , being stimulated by the songs will go after the female . When they are together, the female will carry the male on her back for several days until the ova reaches maturity, after which she will bring the male into water. In water, the female lays dozens of eggs into water. Then the male releases sperms into water to fertilize the ova- an example of external fertililization.
ASEXUAL REPRODUCTION IN PLANARIA / FLAT WORM <ul><li>Two types of reproduction in living organisms: </li></ul><ul><li>Asexual reproduction </li></ul><ul><li>Sexual reproduction </li></ul><ul><li>Figure shows one type of asexual reproduction in animal i.e regeneration </li></ul><ul><li>Describe this type of asexual reproduction. </li></ul><ul><li>Name few other animals and plants that exhibit this type of reproduction. </li></ul><ul><li>What are the advantages and disadvantages of asexual reproduction and sexual reproduction? </li></ul><ul><li>State few other forms of asexual reproduction in plants. </li></ul>
MALE REPRODUCTIVE ORGAN OF HUMAN SIDE VIEW FRONT VIEW A pair of testes is enclosed in the scrotum (folded skin bag) which are located below the pelvis at the exterior of the body. Explain why. What is the function of Cowper’s gland? ( Highly coiled structure) Delivers sperms from testis into seminal vesicle Contains seminal fluid that nourishes the sperms.
MALE REPRODUCTIVE SYSTEM 1. Sperms are produced by meiotic division of germinal epithelial cells in the seminiferous tubules of the testis. 2. Millions of sperms are produced in each of the seminiferous tubule and there are thousands of seminiferous tubules in each testis. 4. Sperm sac / seminal vesicle contains seminal fluid. Immature sperms are stored and nourished here before released. Part of urinary system. 5. Matured sperms are released through urethra during ejaculation. 3. Sperms swim in the fluid of seminiferous tubules into epididymis, and then the sperm duct before entering the seminal vesicle/ sperm sac. Secretes fluid that activates the sperms Cowper’s gland-secretes alkaline fluids
SPERMATOGENESIS It is the process whereby sperms are produced from germinal epithelium cells in the wall of seminiferous tubules of testis by meiosis. One seminiferous tubul of testis. Testis showing seiniferous tubules First meiotic division
TESTIS AND SEMINIFEROUS TUBULES Cell P Cell division X Cell Q Cell division X Cell division Y1 Cell R Cell S Cell division Y2 2n 2n 2n n n Cell T
SEMINIFEROUS TUBULES AND THE SPERM (Sertoli cell) Lumen containing fluid Sertoli cells nourish the immature sperms in the seminiferous tubules. The sperms later swim to the seminal vesicle through epididymis and sperm duct ( vas deferens)
FEMALE REPRODUCTIVE SYSTEM 1. Receives and stores the ovum prior to fertilization. It contains fluid and cilia . Beating of cilia help to move the ovum down the Fallopian tube into uterus 2. Uterus is thick-walled and serves as a place for implantation of the embrio. 3. A muscular tube through which seminal fluid and sperms enter the uterus 4. A pair of avaries is suspended in the coelomic cavity and they are covered by the Fallopian funnels. # # 5. Secondary Oocyte released by the ovary enters the fallopian tube through Fallopian funnels.
SECTION THROUGH OVARY Secretion of FSH hormone ( by pituitary gland) stimulates the development of one follicle in the ovary and that is the start of Oogenesis, the process involved in the production of ovum in ovary. Unlike spermatogenesis, Oogenesis results in the formation of a single ovum.
OOGENESIS Germinal epithelium cell (2n) mitosis Oogonium (2n) mitosis Primary Oocyte(2n) 1 st meiosis Secondary Oocyte(n) 2 nd meiosis Polar body Ovum(n) Polar body Finally degenerates <ul><li>Where are the germinal epithelium cells situated in the ovary? </li></ul><ul><li>At what stage is the number of chromosomes reduced? </li></ul><ul><li>List down the differences between spermatogenesis and Oogenesis </li></ul><ul><li>How is the in-vitro fertilisation carried out? </li></ul>5. Why is there only a single fertilisation takes place?
HORMONAL CONTROL OF MENSTRUAL CYCLE <ul><li>Menstrual cycle- an approximately monthly cycle of events associated with ovulation that replaces the oestrus cycle ( the formation of Graafian follicles, secondary oocytes, ovulation and followed by the formation of corpus luteum). The lining of uterus progressively becomes thicker, with more blood vessels in preparation for the implantation of the zygote/ embryo. </li></ul><ul><li>If fertilization does not occur, the uterine lining breaks down and is discharged from the body, together with blood ( menstruation ) due to the lack of progesteron. The presence of oestrogen stimulate the recovery / next growth of the uterine wall, and the cycle continues. </li></ul>
PMS AND MENOPAUSE <ul><li>PMS (premenstrual syndrome) </li></ul><ul><li>A physiological changes in a woman, a few days before menstruation. It includes: </li></ul><ul><li>-feeling of jealousy </li></ul><ul><li>-pain in the lumbar region </li></ul><ul><li>-headache </li></ul><ul><li>Q: Can you name others? </li></ul><ul><li>Menopause </li></ul><ul><li>A time in a woman’s life when ovulation and menstruation cease. It normally occurs between the ages of 45 and 55. The effects of the gonadotrophic hormones ( FSH and LH ) in the ovaries decrease so that the follicles do not develop properly. There is a change in the balance of hormones oestrogen and progesterone, secreted by the ovaries, which may be associated with certain physical symptoms such as weight gain and ‘hot flushes ’ and there may be also mood changes . These symptoms can be treated by long term hormone replacement therapy with oestrogens and progestrones. </li></ul><ul><li>Q: List down all the physical and physiological changes in a woman suffering from menopause. </li></ul>
SEQUENCE IN ANIMAL/HUMAN DEVELOPMENT #Not to be discussed in detail (not included in the syllabus) # # # morula Zygote (fertilized egg) undergoes several mitosis to form a solid spherical mass of cells, morula which later enters blastocyst stage and finally become implanted in the uterine wall. In human, blastula produces HCGT hormone which serve the function of progestrone prior the formation of placenta. HCGT- human chorionic gonadotrophic hormone
GASTRULATION GASTRULATION # Extra knowledge (not to be discussed)
<ul><li>Figure shows ovulation and the early development of human embrio. </li></ul><ul><li>Explain the process of ovulation </li></ul><ul><li>Explain how a fertilized ovum undergo changes until its inplantation in the uterine wall. </li></ul>
FERTILIZATION 1. Eplain the following: ovulation, fertilization, cleavage of the embryo, blastocyst and implantation process.
STRUCTURE 0f PLACENTA <ul><li>What is a placenta ? </li></ul><ul><li>How and when is it formed? </li></ul><ul><li>What is a finger like structure in the placenta? </li></ul><ul><li>Why is it called a temporary endocrine gland? </li></ul><ul><li>What substances are able to pass accros placental tissue from mother to foetus and vice versa? </li></ul><ul><li>How is placental tissue related to miscarriage? </li></ul>
PLACENTATION Figure shows a foetus in amniotic sac and the structure of a human placenta. Fluid X Explain the function of amniotic fluid. vagina
<ul><li>Figure shows human placenta and its role in the growth of fetus in a mother’s womb. </li></ul><ul><li>Explain exchange of substances between mother’s blood and fetal blood in the placenta. </li></ul><ul><li>Why a drug addicted or HIV mother might be bad for the development of a fetus? </li></ul>
1. Explain the implantation process. 2. How does a woman know she is conceived ( at earlier stage)?
SECTION THROUGH HUMAN FETUS IN UTERUS Amniotic fluid
video <ul><li>video clips of human embryonic development </li></ul>
S&T IN RELATION TO SEXUAL REPRODUCTION BIRTH CONTROL AND IN-VITRO FERTILIZATION <ul><li>Family planning- a program designed to allow spacing and timing of birth of children. It helps to: </li></ul><ul><li>-limit the family size </li></ul><ul><li>-safeguards individual health and rights of the parents and improve the quality of life of the mother and father and their children </li></ul><ul><li>-preserves our planet resources ( humans and the surrounding ). </li></ul><ul><li>-involves several birth control methods/ contraceptive methods: </li></ul><ul><li>IUD- intrauterine device, placed in the uterus </li></ul><ul><li>Cap – to cover the servix , so that no sperms are able to enter the uterus </li></ul><ul><li>strilization – the fallopian tube is cut / tied to prevent entrance of the sperms to the ovum </li></ul><ul><li>Spermicide – a chemicals that kills the sperm, applied on the vagina lining. </li></ul><ul><li>Contraceptive pills, containing progestron and oestrogen at a varying level / conc entrations. </li></ul><ul><li>2. Insemination , involving in-vitro fertilization </li></ul>
In-vitro fertilization Alternative to in-vitro fertilization, insemination in animals is also carried out, especially in animals husbandry. The fallpian tube / oviduct is cut and tied at both cut ends to ensure that there will be no sperms arrived at the ovums. Spermicide is a chemical used to kill the sperms.
IUD is a coiled structure, inserted into the uterus, normally by a trained nurses / doctors. This device vibrates during sexual intercourse, thereby preventing spems from arriving at the ovums in the oviduct. The cap prevents sperms from entering the uterus and thus the oviduct.
NATURAL METHOD Avoid sexual intercourse during fertile phase
Birth Control Methods 1 2 3 4 5 Explain each of the birth control methods as shown in the figure.
<ul><li>Insemination method: </li></ul><ul><li>It is used when the husband is infertile. </li></ul><ul><li>Hormone FSH is injected in a woman / wife to stimulate development of a number of follicles </li></ul><ul><li>Few follicles are identified and selected and placed in a petri dish / testube containing nutrients. </li></ul><ul><li>Sperm from a donor / husband or from the sperm bank is introduced into the petri dish/ test tube containing the ova. </li></ul><ul><li>The zigot / embryo at 8 cells stage is injected into the wife / or surrogate mother’s uterus for implantation </li></ul><ul><li>In-vitro fertilization: please complete the stages of invitro fertilization method. </li></ul><ul><li>Hormone (FSH) is injected into a woman to ………………………………………………….. </li></ul><ul><li>…………………………………………………… </li></ul><ul><li>…………………………………………………… </li></ul>Science and technological savvy in human sexual reproduction.
STRUCTURE OF SEED <ul><li>Thinking Room: </li></ul><ul><li>Describe the function of the endosperm and the cotyledon </li></ul><ul><li>What are the monocotiledonous and the dicotiledonous plants? </li></ul><ul><li>What is a testa? </li></ul><ul><li>Explain the development of the emryo in the monocotliledonous plant and in the docotililedonous plant . </li></ul>
GROWTH Growth is a process involving the increase in the number of cells, size, complexity and function of an organism which are irreversible . Complexity of cell refers to changes in the shape, structure and organisation of the cell to form a tissue and an organ. nucleus Cell wall Water is absorbed A small vacuole is formed Cell division by mitosis Increase in cell size
GROWTH OF CELLS CELL DIFFERENTIATION Guard cell and stomata Mesophyll cell phloem xylem Parencymatous cell of cortex
THE GROWTH STAGE OF A CELL <ul><li>Cell Division </li></ul><ul><li>Cell divison during a growth process is by mitosis to multiply the number of cells in an organism. </li></ul><ul><li>The increase in cells number is by geometric progression or exponential increases: 1 2 4 8 16 …….to produce thousands of cells in the organism. </li></ul><ul><li>Cell Enlargement </li></ul><ul><li>Cell division is followed by cell enlargement i.e the increase in size of each cell. </li></ul><ul><li>In plant cell, this is achieved by the absorbtion of water into the vacuole. </li></ul><ul><li>The entrance of water causes the vacuole to expand, becoming longer and wider because of an increase in the turgor pressure ( find out about turgor pressure ) </li></ul><ul><li>In animal cell, the increse in cell size is by assimilation of food substances and the absorption of water to synthesis the protoplasmic substances. </li></ul>
<ul><li>Cell differentiation </li></ul><ul><li>A cell will undergo differentiation process after achieving a maximum size and changes shape and complexity to form a specialized cell. </li></ul><ul><li>A specialized cell carries out special function eg. nerve cell transmits impulse in a nervous system and xylem vessel transports water in a plant. </li></ul><ul><li>In plants , the meristematic cells and the embryonic cells( which are unspecialized) differentiate to form several different specialized cells and tissues eg. parenchymatous cells / tissue in plant and nerve cells, muscle cells in animals. </li></ul><ul><li>Cell diffrentiation to form various tissues is under the control of genetic materials found in DNA and chromosomes. </li></ul><ul><li>DNA contains genes which specify the proteins to be synthesized in the cell / organism. </li></ul><ul><li>Different types of proteins in the cell determine the different types / specificity of cells and tissues that are formed in the organism. </li></ul>THE GROWTH STAGE OF A CELL
THE GROWTH ZONE IN A PLANT SHOOT Zone of cell division/ growth zone Zone of cell elongation Zone of cell differentiation Matured tissue Leaf primordium xylem phloem cambium Apical meristem -produces leaf primordium which protects the meristematic tissue Axial bud -containing cells which are capable to divide to form side branches.
THE GROWTH ZONE IN A PLANT ROOT Root hair phloem xylem Matured tissue Zone of cell division/ growth zone Zone of cell differentiation Zone of cell elongation cortex Apical Meristem Root cap
MEASUREMENT OF GROWTH The parameter usually used to measure growth in a multicellular organism is the changes in length, dry mass or height with respect to time. Eg. changes in the length of the tail, the height of a plant or humans, the length of a fruit or a diameter of the leaf can be used in the measurement of growth of organisms. Another parameter of growth is dry mass. Dry mass is the mass of ( partly / the whole) organism when water is completely widthdrawn from the organism by drying (eg. in an oven / temperature about 110 0 C) until the last few measurements of mass are unchanged. Fresh weight is not suitable. Why? Measurement of dry mass is more accurate in the measurement of growth because it is possible to get more than one readings in order to obtain an average reading. On the other hand, it has the advantage too because the organisms has to be destroyed , they should be of about the same age and size at the time of the experiment.
GROWTH CURVE OF A HUMAN Time / year Growth ( height/ weight) At birth Rapid growth Slow growth Very rapid growth Very little growth death senescence adult / Adolescence / childhood baby
GROWTH OF HUMAN ORGANS The difference in relative growth rate of the human body, heart and brain. Age/year body heart brain Growth /part of body weight at birth
GROWTH CURVE OF HUMANS Age / month Height / cm foetus 7 weeks until birth baby Embryo (0-6 weeks)
GRWTH OF A BOY AND A GIRL Rate of increse in height Kadar pertambahan berat Age / years Height / cm boy girl Fresh weight Rate of increse in weight boy girl Age / years
GROWTH STAGES <ul><li>1. nitial Growth: </li></ul><ul><li>The beginning of the growth process </li></ul><ul><li>The rate of growth is generally low </li></ul><ul><li>Cell division by mitosis takes place very actively but there is no increase in cell size. </li></ul><ul><li>2. Exponential Growth: </li></ul><ul><li>The highest growth rate </li></ul><ul><li>Cell size increases by absorbing water and and addition of protoplasmic subsatances. </li></ul>
<ul><li>Maturity Stage </li></ul><ul><li>Growth rate is low </li></ul><ul><li>Cells achieve the optimum size and there is no more increase in size of the cell. </li></ul><ul><li>A little cell division to replace damaged cells </li></ul><ul><li>Adulthood Stage </li></ul><ul><li>Growth rate is zero </li></ul><ul><li>Cells still divide to replace damaged / dead cells </li></ul><ul><li>5. Senescene Stage </li></ul><ul><li>Growt rate is negative because of loss of tissues due to aging process </li></ul><ul><li>Finally, the death of the organism </li></ul>
LENGKUNG PERTUMBUHAN TUMBUHAN <ul><li>Terangkan proses pertumbuhan pada peringkat : </li></ul><ul><li>AB </li></ul><ul><li>BC </li></ul><ul><li>CD </li></ul><ul><li>DE </li></ul><ul><li>EF </li></ul>Mengapakah pola pertumbuhan haiwan berangka luar berbentuk tangga? Beri contoh haiwan-haiwan berangkan luar. Apakah yang berlaku semasa ekdisis?
PERINGKAT PERTUMBUHAN 1. Bandingkan pertumbuhan dalam : a) Haiwan dan tumbuhan b) Haiwan berangka luar dan haiwan berangka dalam 2. Bagaimana anda mengukur kadar pertumbuhan mikroorganisma seperti bakteria?
Lengkung pertumbuhan Belalang Juta Lengkung pertumbuhan belalang juta (serangga) <ul><li>Huraikan lengkung pertumbuhan belalang juta </li></ul><ul><li>Terangkan perubahan yang berlaku pada belalang juta semasa ekdisis </li></ul><ul><li>Huraikan kitaran hidup serangga seperti belalang juta </li></ul>imago telur nimfa Nimfa instar I Nimfa instar II Nimfa instar III Nimfa instar IV Nimfa instar V
ZON PERTUMBUHAN DALAM TUMBUHAN Pertumbuhan berlaku dalam zon meristem apeks dan meristem sisi ( tisu kambium ) melalui pembahagian sel-sel menghasilkan banyak sel-sel baru., menyebabkan pertambahan panjang / ketinggian dan ukur lilit batang / akar 3 zon pertumbuhan dalam akar: