Heterospory:It is a phenomenon in which two kinds of spores are borne by the same plant. These spores differ in size. The smaller one is known as microspore and the larger one is known as megaspore.

The microspore germinates to form the male gametophyte and the megaspore germinates to form the female gametophyte. The male gametophyte releases the male gametes and these reach the female gametophyte to fuse with the egg. The development of the zygote takes place inside the female gametophyte.

Platyhelminthes: Triploblastic, acoelomate, unsegmented and bilaterally symmetrical metazoans, without ****, circulatory system, but with a mouth, protonephridial system, parenchyma tissues within the space between the body wall and the gut, and spiral cleavage development.

Characteristic Features of Phylum Platyhelminthes:
1. Phylum Platyhelminthes are triploblastic, acoelomate (without a body cavity) and bilaterally symmetrical animals.
2. Body is soft, un-segmented and dorsoventrally flattened.
3. Metameric segmentation and skeletal structures, in any form, are absent. Pseudometamerism is seen in some members (e.g., Eucestoda).
4. Anterior end of the body is differenti­ated into a head.

Chloroplasts:The small organelles inside the cells of plants and algae are called Chloroplasts. They absorb light to make sugar in photosynthesis. The sugar is stored in the form of starch. Chloroplasts contain chlorophyll which absorbs sunlight for photosynthesis.

Granule Cell of the Cerebellum is the smallest cell of the human body it is approximately 4um to 4.5um in size.

Every organism can be classified at 7 different levels -

1. kingdom
2. phylum
3. class
4. order
5. family
6. genus 
7. species.

Each level contains organisms with similar characteristics. The kingdom is the largest group and very broad.

Biomolecules are molecules that occur naturally in living organisms. Biomolecules include macromolecules like proteins, carbohydrates, lipids and nucleic acids. It also includes small molecules like primary and secondary metabolites and natural products.

Claspers are an external appendage found on male sharks, skates, and rays that are designed to deliver sperm inside of a female. However, they are dissimilar to a ***** in that they are not an independent appendage, but rather a deeply grooved cartilaginous extension of the sharks pelvic fins.

As a building is made up of numbers of bricks basically 

similarly the living organisms are made up of a very fundamental structure called CELL

• defined as ,, the fundamental structural and functional unit of life
• discovered by Robert Hook's in 1665
• by using simple microscope 🔬 
• a typical cell consist of a nucleus, cytoplasm and cell membrane.
• there are two types of cells on the basis of level of development of membranes of cell organelles as

1. PROKARYOTIC CELLS
2. EUKARYOTIC CELLS

The egg laying organisms are known as oviparous like frogs

and the other term is viviparous used for the organisms which give birth to young once like human beings

The International Union for Conservation of Nature (IUCN), officially International Union for Conservation of Nature and Natural Resources is an international organization working in the field of nature conservation and sustainable use of natural resources.