Cell & animal reproduction Grade 6 Compiled by: Alya Kays Plants reproduction Animal Cell • The body is made up of millions of tiny cells • Most of the cell is made up of protoplasm • Cell parts: Nucleus Cytoplasm Cell membrane Animal Cell Nucleus Cytoplasm Cell Membrane SHAPE • Plant cell is rectangular in shape. • Animal cell is spherical in shape. Plant cells Animal cells CELL WALL • Plant cell is covered by a thick cell wall. • Cell wall is made up of cellulose and hemicellulose. • Animal cell is covered by a thin cell membrane. • It is made up of Lipoprotein. VACUOLE • In plant cell, Vacuole is big, prominent and permanent. Vacuole • In animal cell, Vacuole is small, temporary and not so prominent. PLASTIDS • Plastids are present only in plant cell. • Plastids are of three types. • *Leucoplast • *Chromoplast • *Chloroplast • PLASTID IS ABSENT IN ANIMAL CELL. Paramecium Skeletal muscles attach to bones. They help you do things such as kick a ball, chew food, or write. When one of these muscles contracts, or shortens, the bone attached to the muscle moves. Skeletal muscles are voluntary—that is, you control when they work. Skeletal muscles consist of cells containing light and dark bands that make them appear striped. Nerve cell: This photomicrograph shows a number of multipolar nerve cells. The central cell body is clearly visible in each of the cells, as are the dendrites. The dendrites are short extensions of the nerve cell body that function in the reception of stimuli. • The epithelium is a protective layer of cells that covers an organ surface or lines a body cavity. Shown here is a layer of simple squamous (scaly) epithelium. Skin is composed of several layers of epithelial cells. Bone cell Osteocytes Cell Division • Mitosis – Increases total number of cells – Results in animal growth – Chromosomes pairs are duplicated Cell Division • Meiosis – Produces gametes – Only have one-half the chromosomes of normal cells Gametes Reproductive Terminology Species Cows Ewes Sows Hens Mares Goats Frog Act calving lambing farrowing hatching foaling kidding hatching Offspring calf lamb pig chick foal kid tadpole Mammals Reproduction Objective: Specify how the reproductive system for mammals functions Terminology • Estrus – When a female is receptive to be bred • Lactation – Period of time that milk is secreted by the mammary glands • Parturition – Than act of giving birth Reproductive Functions of the Female Estrous cycle - time from one heat period (or menstrual cycle) to the next. Length of estrous cycle by species: Cow 19 - 21 days Ewe 16 - 17 days Sow 19 - 21 days Mare 21 - 24 days Woman 28 days Hen none Female Tract Female Reproductive System • Ovary - the ovary is comparable to the male testicle and is the site of gamete production. – A bovine animal has 20,000 potential eggs per ovary, while a human female has 400,000 potential eggs per ovary. – Ova are fully developed at puberty and are not continuously produced as in the male. – All species contain two functional ovaries except for the hen which has only a left functioning ovary. Female Reproductive System • Uterine Horn - The anterior, divided end of the uterus in the cow, ewe, and mare. Sow has only 2 horns, no body, woman has no horns, only body. • Uterus - Muscular sac connecting fallopian tubes and cervix 1. Sustains the sperm and aids in its transport 2. Supports embryo and fetus during gestation 3. Expels fetus at parturition Female Reproductive System Reproductive Functions (Female) Steps in the female reproductive process: 1. Ovulation — Produce gamete (ova or ovum) — Release of egg(s) — Infundibulum pushes the ovum into the fallopian tube Ovulation Rates Ovulation Rates by Species Cow1 egg per estrus Ewe1 to 3 eggs per estrus Sow10 to 20 eggs per estrus Mare1 egg per estrus HenApprox. 28 eggs per month Fertilization • When the sperm from a male reaches the egg from a female • Two cells join to form a complete cell • Pairs of chromosomes are formed again • Many different combinations of traits are formed Fertilization Figure 16.13 Fertilization Reproductive Functions (Female) Gestation and Lactation Periods: Species Cow Gestation Period 275 - 285 days Ewe Sow Mare Woman 115 112 330 270 - 142 days - 115 days - 345 days days Lactation(Milking) beef 180 - 270 days dairy 305 - 365 days 60 - 90 - 120 days 21 - 42 days 90 - 150 days ? years Baby development Human baby Birds Reproduction in Poultry Objective: Specify how the reproductive system for poultry functions Reproduction in Poultry The poultry oviduct has five parts: 1) Vagina – Holds the egg until laid 2) Uterus – Secretes the shell 3) Isthmus – Adds the two shell membranes 4) Magnum – Secretes the albumen 5) Infundibulum – Where fertilization takes place Reproduction in Poultry • Major difference: – Embryo of livestock develop inside the female’s body while the embryo of poultry develops inside the egg. • Poultry only have the left ovary and oviduct when mature • The yoke is the ovum • Chicken Incubation – 21 days 1- A butterfly starts its life as an egg, laid by a female adult butterfly after mating. Butterfly eggs vary in size and shape, but most are surrounded by a protective hard shell. 2- A caterpillar develops within the egg and then eats its way out of the shell. • 3- When the caterpillar reaches its final size it stops feeding. The caterpillar wriggles and twists to gradually remove its old skin, revealing a new protective skin called the chrysalis. 4- A caterpillar spends all its time eating. As it grows, the caterpillar becomes too large for its skin and molts (sheds its skin) to reveal new skin. Depending upon the type of butterfly, caterpillars molt four or five times. 5- Inside the chrysalis, the caterpillar changes from a wormlike creature into an adult butterfly. 6- When the butterfly reaches adulthood, it leaves the chrysalis. It pumps blood into its crumpled wings and expands them to their full size before flying away. Amphibians Life Cycle of a Frog Metamorphosis • Metamorphosis is the changes that a frog goes through during its life cycle. • There are four main stages in the life cycle of the frog. Egg • The first stage in the life cycle of the frog is the egg. • A frog lays many eggs at one time. • The eggs are covered with a jellylike coating. Tadpole • The second stage of the frog life cycle is the tadpole. • Hatched tadpoles have gills for breathing in the water. • They have a tail, but no legs. • As a tadpole grows, lungs begin to form. • Back and front legs begin to grow. These parts allow the adult frog to live on land. Adult Frog • Once the lungs form and begin to work, the gills and tail disappear. • The adult frog is now ready to live on land. Frog life cycle This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching. Free Powerpoint Presentations 66