MUSCULAR SYSTEM IN HUMANS

DIGESTIVE SYSTEM IN HUMANS

EXCRETORY SYSTEM IN HUMANS

HUMAN NERVOUS SYSTEM - CROSS SECTION OF BARAIN

Different Diagrams of Structure of Long Bones

SKELETAL SYSTEM - HUMANS

Flower Structure and Reproduction

Flower Structure and Reproduction

Flowers are the plant's reproductive structures. Angiosperms are types of plants that bear fruits and flowers. Flowers are usually both male and female, and are brightly colored to attract insects to help them carry pollen used for sexual reproduction. Not all flowers are colorful, though. These flowers usually use the wind for pollination.

Parts of the Flower

The receptacle is the part of the branch on which a flower forms. Color the receptacle (B) brown. Sepals are leaf like structures that surround and protect the flower before it blooms. Color the sepals (C) green. Petals are the colorful part of the flower that attracts insects and even other small animals, such as mice, birds, and bats. Color the petals (D) a bright color of your choice. All flowering plants have flowers, but some are not brightly colored. The petals of these flowers are reduced or absent and the plant relies on the wind or water for pollination.

The flower has both male and female reproductive parts. The female reproductive structures are called carpels. In most flowers, the carpels are fused together to form a pistil. Color the pistil (P) pink. The pistil has three parts, which can be seen, in the box labeled "pistil". The stigma at the top is often sticky and is where the pollen attaches. Color the stigma (J) purple. The style is the long tube that attaches the stigma to the ovary. Sperm from the pollen will travel down this tube to the ovules. The ovules, or eggs, are stored in the ovary until they are fertilized. Plants can only fertilize eggs of the same species. Special chemicals prevent sperm from fertilizing the eggs of flowers that are not the same kind. Color the style (K) red, and the ovary (L) pink. Color the ovules (O) black.

The male reproductive structures are called the stamens. Color the stamens (H) blue. Each stamen consists of an anther (A), which produces pollen, and a filament (F), which supports the anther. In the box labeled "stamen" color the anther dark blue, and the filament light blue. Pollen produced by the anther is carried by insects or other animals to the pistil of another flower where it may fertilize the eggs.

The other flowers in the picture follow the same plan, although they come in many different colors and styles. Color each of the flowers according to the colors above (blue for stamen, pink for pistil, bright colors for the petals. etc.). Note that in some of the flowers, not all the structures are visible.

Plant Reproduction

Sexual reproduction in plants occurs when the pollen from an anther is transferred to the stigma. Plants can fertilize themselves: called self-fertilization. Self-fertilization occurs when the pollen from an anther fertilizes the eggs on the same flower. Cross-fertilization occurs when the pollen is transferred to the stigma of an entirely different plant.

When the ovules are fertilized, they will develop into seeds. The petals of the flower fall off leaving only the ovary behind, which will develop into a fruit. There are many different kinds of fruits, including apples and oranges and peaches. A fruit is any structure that encloses and protects a seed, so fruits are also "helicopters" and acorns, and bean pods. When you eat a fruit, you are actually eating the ovary of the flower.

ADAPTATIONS FOR TYPES OF POLLINATION

Adaptations  to Insect and Wind Pollination

Adaptations of Insect Pollinated Flowers

• Attract Pollinators: brightly coloured petals, petal shape, food reward – pollen and/or nectar, fragrance – volatile chemicals released into the air.
• Pollen Collection by Insect: sticky pollen – stays in contact with anther until insect arrives.
• Pollen Capture By Flower: sticky stigmas so pollen from insect will transfer to them.

Adaptations of Wind Pollinated Flowers

Pollen Collection by Wind: smooth – easily removed from anther, small pollen easily transported by the wind.

Pollen Capture by Flower: stigmas large and feathery – greater surface area to intercept pollen, stigmas outside the flower

Massive Pollen Production: compensate for the excessive losses.

Note:

• An adaptation is a feature (behaviour or modified structure) which fits the organism better to carry out a particular function.
• Ideally name or describe the feature and then give its advantage.

The absence of a feature is not an adaptation.

POLLINATION IN FLOWERS

Flower Structure

Parts of Light Microscope

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Microscope Parts and Functions
A microscopes function is to see things at different levels, magnifications e.g. cells that can not be seen with a naked eye.
1. Eyepiece: The eyepiece (sometimes called the 'ocular') is the lens of the microscope closest to the eye that you look through. It is half of the magnification equation (eyepiece power multiplied by objective power equals magnification), and magnifies the image made by the objective lens... sometimes called the virtual image. Eyepieces come in many different powers. One can identify which power any given eyepiece is by the inscription on the eyecup of the lens, such as "5x", "10x", or "15X". Oculars are also designed with different angles of view; the most common is the wide field (W.F.).
2. Eyepiece Holder: This simply connects the eyepiece to the microscope body, usually with a set-screw to allow the user to easily change the eyepiece to vary magnifying power.
3. Body: The main structural support of the microscope which connects the lens apparatus to the base.
4. >Nose Piece: This connects the objective lens to the microscope body. With a turret, or rotating nose piece as many as five objectives can be attached to create different powers of magnification when rotated into position and used with the existing eyepiece.
5. Objective: The lens closest to the object being viewed which creates a magnified image in an area called the "primary image plane". This is the other half of the microscope magnification equation (eyepiece power times objective power equals magnification). Objective lenses have many designs and qualities which differ with each manufacturer. Usually inscribed on the barrel of the objective lens is the magnification power and the numerical aperture (a measure of the limit of resolution of the lens).
6. Focusing Mechanism: Adjustment knobs to allow coarse or fine (hundredths of a millimeter) variations in the focusing of the stage or objective lens of the microscope.
7. Stage: The platform on which the prepared slide or object to be viewed is placed. A slide is usually held in place by spring-loaded metal stage clips. More sophisticated high-powered microscopes have mechanical stages which allow the viewer to smoothly move the stage along the X (horizontal path) and Y (vertical path) axis. A mechanical stage is a must for high-power observing.
8. Illumination Source: The means employed to light the object to be viewed. The simplest is the illuminating mirror which reflects an ambient light source to light the object. Many microscopes have an electrical light source for easier and more consistent lighting. Generally electrical light sources are either tungsten or fluorescent, the fluorescent being preferred because it operates at a cooler temperature. Most microscopes illuminate from underneath, through the object, to the objective lens. On the other hand, stereo microscopes use both top and bottom illumination.
9. Base: The bottom or stand upon which the entire microscope rests or is connected.
Compound light microscope:
Microscope Part Function
Eyepiece (ocular lens) The part you look through. It has a lens that magnifies the object, usually by ten times (10x). The magnifying power is engraved on the side of the eyepiece. Tube Holds the
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eyepiece and the objective lenses at the proper working distance from each other. Revolving nosepiece Rotating disk holds two or more objective lenses. Turn it to change lenses. Each lens clicks into place. Objective lenses Magnify the object. Each lens has a different power of magnification, such as 10x, 40x, and 100x.The magnifying power is engraved on the side of each objective lens. Be sure you can identify each lens. For example, the low-power objective lens is usually 10x. Fine-adjustment knob Use with medium- and high-power magnification to bring the object into sharper focus. Coarse-adjustment knob Moves the tube or stage up or down and brings the object into focus. Use it only with the low-power objective lens. Stage Supports the microscope slide. Clips hold the slides into position. A hole in the center of the stage allows the light from the light source to pass through the slide. Condenser lens Directs light to the object being viewed. Diaphragm Use this to control the amount of light reaching the object being viewed. Light source Shining a light through the object being viewed makes it easier to see the details. (Your microscope might have a mirror instead of a light. If it does, you will adjust it to direct light through the lens.) Overall, the function of a microscope is to view specimens too small to be viewed by the human eye. and the other four are not here

REFLEX ARC

VILLI IN SMALL INTESTINE

STRUCTURE OF NEURON

BASIC STRUCTURE OF THE HUMAN EYE