Biology revision points and complete definetions of all questions and biological problems

Movement: This is very easy to see in most animals, but it is not easy to see in plants way in movement. Movement may occur when the organism needs some kind of source to live better may be for food and hunting for shade and even to hide from predators. Most plants are rooted to the ground so the whole plant cannot move. But parts of plants may slowly perhaps only the contents of their cells move. So that you only see the movement under a microscope.

Respiration: This means that they break down food inside their cells, sometimes by combining it with oxygen. This releases energy from the food, and the organisms can use this energy to carry out the rest of the seven characters.

Sensitivity: Living organisms are sensitive towards their surroundings. They can sense changes in their surroundings and respond to this change. This is sometimes also called Irritability. The changes they sense are of many types, such as temperature, light intensity, sound, day length and the presence of chemicals and the amazing sense of danger when predators are around.

Growth: Living organisms grow. Some of the nutrients they feed on provide them with the energy needed to help the cells in the organisms to grow, and to build new cells, so that the organisms grow larger.

Reproduction: Living organisms reproduce, every kind of living organisms is able to make new organisms like it self, either by self dividing or in other words Asexually or by having a partner like in most cases male and female will out go and reproduce Sexually.

Excretion: Living organisms excrete, chemical reactions take place inside the cells of an organism, some of the substances made during or by the reactions which are chemically done can be poisonous, so the organism needs to get rid of those substances.

Nutrition: Living organisms need to feed. They need to take in substances from their surroundings. They use these substances for growth, or as a source of energy to continue on living properly and to out go all the other characteristics.

Classifying living organisims.

No body knows how many different kinds, or species of living organisms there are on earth. About 1.4 million different species have been described and named. But many biologists think that this may only be one tenth of the species on earth! We have almost certainly discovered most of the large land animals, but there are probably many animals living in the deep oceans which have never been seen by humans. And biologists estimate that there are certainly millions of insects and smaller animals and plants that have not yet been discovered.

To make it easier to study this organism’s biologist has sorted them into groups. This sorting is called Classification. Living organisms have evolved over 100 of millions of years. Living organisms are all related to one another biologist classify them by putting closely related organisms in to the same group.

The vertebrates

One group of the organisms is the vertebrates. The vertebrates all belong to a large group or phylum, called chordates. The chordates all have a stiffening rod that runs along inside the upper surface of their body. In the vertebrates this rod has been replaced by a row of bones have vertebral column or backbone.

There is a smaller and easier way to remember vertebrates classes: FARM-B

Fish: Nearly all fish live in water. Their skin is moist and covered in scales. Gaseous exchange occurs through gills and fins and tails assist in movement and the balance in the water. Fish have a sense organ called the lateral line running along the side of the body, it can detect vibrations in the water.

Amphibian: The class amphibians contains frogs, toads, salamanders and newts. Theses animals have smooth moist skins with no scales. The adults have four limbs and they live on land but they always have to go back to the water to breed. They lay their eggs in the water, where they hatch in to tadpoles, the tadpoles breathe through gills like fish , but under go a dramatic change called Metamorphosis , to become adult and breathe through lungs and their skin.

Reptiles: The reptiles have tough scales all over their body they may live in water like turtles and crocodiles or on land like many lizards and snakes most reptiles apart from snakes have four legs. Reptiles have rubbery shelled eggs which are always laid on lands.

Mammals: Any vertebrate with hair is a mammal. Mammals have a prominent flap on the out side of the ear called Pena. They do not lay eggs, the young mammal develop in side the body of the mother attached to her by the umbilical cord and placenta after birth the young are cared for by their parents and feed on milk from their mothers mammary glands.

Birds: Birds are closely related to reptiles, their body is covered with feathers which help to keep them warm, some parts of the body usually the lower part of their legs, are covered with scales instead of feathers they lay eggs with hard shells all birds have either beaks or bills, and all have 2 wings for flight.

Arthropods: If you judge success by sheer numbers the phylum arthropoda wins by a huge margin. The arthropods do not have a back bone they are called invertebrates they have a skeleton out side the body, called an exoskeleton and jointed legs. The exoskeleton covered by a water proof layer called a cuticle protects water proof and supports and allow movement to occur.

With in the arthropods there are 3 main classes:

1) Arachnids ( arachnida)-Spiders, ticks and scorpions.

2) Crustaceans (crustacean)-Lobsters, crabs and wood lice.

3) Insects (insecta)-Ants, butterflies and lady birds.

4) Myra pods-Millipedes and centipedes

remember: Insects are segmented in to 3 parts 1) head 2) thorax 3) abdomen and the legs in most insects are usually attached to the thorax and wings to the thorax also insects have six legs and 2 pair of wings in most cases except a certain fly and have one pair of antennas and have compound eyes.

Remember: Arachnids are segmented in to two parts cephalothoraxes and the abdomen cephalothoraxes just simply mean that their head is attached to their thorax and they have 8 legs also they have no antennas and they have eyes a good example is a spider.

Remember: Crustaceans are also cephalothoraxes and have jointed legs they have a hard shell covering them called a ( carapace) covering their segmented body and they have a calcified skeleton made out of calcium salts and they have above 8 and less then 20 as a range for the number of legs they own. They have 2 pairs of antennas

Remember: Myra Pods are highly segmented they have one pair of antennas and they are leg jointed their exoskeleton is made of chitin and they have a head and they also have eyes the range of legs they have is above ten less than twenty good examples of Myra pods are centipedes and millipedes.

Fungi :In some ways fungi are a little like plants, They grow rooted to the spot and do not move around. However, fungi do not photosynthesis, and do not have chlorophyll. Instead, they feed on other living or dead organisms. They do this by producing enzymes which seep out from the fungus in to what ever it is growing on. The enzymes digest this food, which is then soaked up into the fungus’s body. This is called Apostrophic feeding.

The main body of a fungi is called a Mycelium. It is made up of many threads called Hyphae. The hyphae grow through what ever the fungus is feeding on-perhaps a piece of bread, or through the soil. Each hyphae is surrounded by a cell wall, but this is not made of cellulose like that of plant cells. Different fungi have different substances in their cell walls, but many of them have cell walls made of chitin-the exoskeleton of insects is also made of chitin. At a certain time of year, some fungi grow a (mushroom) above the ground. This is for reproduction, which is done by producing thousands of tiny spores.

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