Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
1)Similarities-Mitosis produce new offspring of same species DifferencesSexual Involve Two parents Involve one male and one female gamete Involve meiosis Offspring is not genetically identical to parent Example: human, cat, dog Asexual involve only One parent No gamete involved Involve mitosis Offspring is genetically identical to parent Example: Amoeba, yeast, starfish 2)a) Spermatogenesis b) Germ cells are found at the seminiferous wall. Germ cells go through the process of mitosis and form many spermatogonia. This takes place when boy reach puberty. All spermatogonia will then go through the process of growth and form primary spermatocyte. Primary spermatocyte then goes through meiosis 1 and become secondary spermatocyte. After this, secondary spermatocyte then goes through meiosis 2 and form spermatid and lastly it will form sperm through differentiation. c)Oogenesis d)Germ cells are found at the epithelium of ovary. Germ cells than goes through mitosis and form many oogonia. This process takes during embryo stage. Only one oogonium goes through the process of growth and the rest of it degenerates. One primary oocyte then goes through meiosis 1 and form one secondary oocyte and one polar body. The size of secondary oocyte is bigger than polar body because of uneven distribution of cytoplasm happens. The secondary oocyte and polar body goes through meiosis 2 and form one ovum and 3 polar bodies. e)Similarities -Goes through the process of mitosis Goes through the process of meiosis Differences – spermatogenesis oogenesis thousands of sperms produced only one ovum is produced no polar body formed 3 polar bodies are formed occurs during puberty occurs during embryo stage sperms are in same size uneven distribution of cytoplasm occurs takes place in testis takes place in ovary 3)a)Follicle stimulating hormone(FSH) Luteinising hormone(LH) Oestrogen Progesterone b)After menstruation, pituitary gland secretes Follicle stimulating hormone(FSH) for development of egg follicle. The developing egg follicle then secretes oestrogen . Oestrogen helps repair and thicken endometrium. High level of oestrogen stimulates pituitary gland to secrete luteinising hormone (LH). LH stimulate ovulation and development of corpus luteum. Corpus luteum then secretes progesterone. progesterone helps to thicken the endometrium. If fertilization does not occur, then corpus luteum will degenerate and level of progesterone will decrease. This causes the endometrium to break down . Menstruation will occur. c)The woman will become more emotional and she will mentally disturb. The woman may unable to carry a baby due to hormone imbalance 4)Menopause is when your body stops ovulation and this happens at a certain age after 50-60 years. Menopause affect the woman by making her very emotional , she might get a headache because of her uneven level of hormones. She might even get ovary cancer . 5)a)After the development of zygote after fertilisation , the zygote will go through four days of mitosis . after that, the zygote will form a morula , and then a blastocyst is form. Blastocyst will then implant to the uterus. In the blastocyst, the inner cell mass develops into embryo and the trophoblast sends out villi to the wall and then form the placenta . b)Identical twins Fraternal twins share one placenta two different placenta identical characteristics non-identical characteristics involve only one ovum and one sperm involve two ova and two sperms same sex different sex one zygote split into two two zygotes are formed occurs during the process of fertilisation 6)a)A: Umbilical arteries B: Umbilical veins C: Placenta Amniotic fluid D: Amniotic sac E: Umbilical cord b)The placenta needs to be thick to not allow any substances to enter in thin wall, to allow diffusion of substances occurs easily. c)Because when a pregnant mother takes drugs or smoke, those things is small enough to go through the placenta and into the foetus. This will then cause the foetus to be disable in the future. Development of foetus, mentally retarded d)To exchange the substances between the foetus and the mother Absorb shock e) If blood group is incompatible it will cause agglutination. To prevent microorganism to enter into the foetus. Protects high pressure from mother Because the baby unable to withstand high blood pressure. Separated circulatory system protects the baby from getting invaded by microorganism. 7)a)i)condom ii)sperm bank vasectomy/ tubal ligation iii)oral contraceptive pill b) the guy must wear the condom during sex Condom is wear on man’s penis, it helps to prevent sperm from entering vagina. c)The hormone is injected into the mother every day. Use the ultrasound to detect whether ovum is produced, insert a needle inside to take the ovum out . Then, put the ovum, sperm and culture medium into the petri dish and let fertilization occur . After embryo is formed it is placed into the uterus using a catheter and then pregnancy test is carried out . d)Sexually transmitted diseases is disease passed through sexually . To prevent it we must prevent having many sex partners and using a condom during sex 8)a)only one embryo cell enlarges and form embryo mother sac cell . Diploid nuclei of mother sac cell goes through meiosis and form 4 haploid cells . Three haploid cell is degenerated and one is left. It goes through mitosis 3 times and form 8 nuclei . Two synergids , two polar nuclei , one egg cell and three antipodal cell are formed. Then 2 layers of integuments are formed around the embryo sac and micropyle which is a small opening b) After pollen grain lands on the stigma, Stigma then releases sugary liquid to germinate the pollen. During the germination of pollen, pollen tube is formed. During formation of pollen tube, generative nucleus will form 2 male nuclei. This will then have two male nuclei . When the pollen tube reaches the embryo sac, The tube nuclei will degenerates . One male nucleus will fuse with the egg cell and form zygote . After maturation, it will become embryo. The other male nucleus will fuse with the two polar nuclei and form triploid nucleus, then it will become endosperm that is food for the embryo. This process is called double fertilization. 9)a)Growth is an irreversible process which involves increase of number of cells , size , organ function and complexity . b)The three stages of growth is cell division , cell elongation and cell differentiation. In cell divison , cell go through mitosis , it makes the cell small and identical. In cell elongation, cells increase in size ,for animal cell, it enlarge by assimilation of food , for plant cell to grow they go through vacuolation . In cell differentiation , cells differentiates to specialized cell . c)The parameters which can measure growth are length and height. The disadvantages of this is that it is not completely accurate because it did not take into consideration in other dimension. The next parameter is volume , the disadvantage is we cannot measure it if its irregular shape. The other parameter is fresh mass , the disadvantage is the volume of water is keep changing. The last parameter is dry mass , the disadvantage is that u have to kill the organism. 10)a)Insects b)Ecdysis happens at point A, the insects sheds their inelastic and hard exoskeleton so that they can grow bigger in size. After they shed their exoskeleton , their body take in air and water , this helps to expand their body to a bigger size . Their body will then build cells and tissues in the expanded volume. Over time , their exoskeleton will then slowly grow harden and the insect will stop growing in size. 11)a)Lateral meristem has two types of meristem which is vascular cambium and cork cambium. Vascular cambium and cork cambium helps to strengthen the plant by its diameter. This is because in primary growth the plants grows in height so it is tall and heavy. So in secondary growth the plants grow is width to support the weight of the plant . Vascular cambium goes through cell division forms a lot of cambial cells. The cambial cells link together to form cambium ring. The cells in the cambium ring divides actively and causes primary xylem to be pushed inwards, while primary phloem is pushed outwards. Cork cambium divides actively forms cork cells. The inner part of cork cambium will become secondary cortex, the outer part of cork cambium will become cork. b)i)C ii)F iii)A iv)D v)G