• Hard and soft water.
  • Advantages of hard water.
  • Disadvantages of hard water.
  • Advantages of soft water.
  • Disadvantages of soft water.
  • Types of water hardness.

Hard and soft water.

Hard water is water which contains dissolved salts ie magnesium and calcium. Mainly from sea,
oceans, boreholes, lakes and dams.

Soft water is water with no or little dissolved salt in it. Mainly rain water.

Advantages of hard water.

• Contains dissolved minerals which are good for our health.
• It has a good taste to drink.
• It is good in brewing industry.

Disadvantages of hard water.

• Wastes a lot of soap because it does not lather easily.
• It discolours teeth when drank.
• It stains clothes.
• It causes clogging and blocking of pipes.
• It forms scales or fur on boilers and hot water pipes.
• Wastes a lot of time and energy during laundry.

Advantages of soft water.

• Does not stains teeth.
• Best in laundry.

Disadvantages of soft water.

• Does not have a good taste.
• Has no minerals required by the body.

Types of water hardness.

There are two types of water hardness, namely;

• Temporary water hardness.
• Permanent water hardness.

Temporary water hardness can be removed by boiling or distillation. Permanent water hardness can be removed by adding chemicals.

NB: The process of removing the dissolved minerals from hard water is called softening.

• Adaptations of animals to their environment
  • Feeding habitats in mammals.
  • Feeding adaptations in birds
• Adaptations of Animals to Movement.
  • Adaptations to Flying.
  • Adaptations to Swimming
  • Adaptations to Hopping and Leaping.
• Signs of Ill Health in Livestock.
  • Effects of Livestock Diseases.

Adaptations of Animals to their Environment

Feeding Habitats in Mammals.

Herbivores.

These are mammals that feed on plants eg cow, buffalo, antelopes, elephants etc

They are classified into two, namely;

• Grazers- They feed on grass eg cattle, buffalo, hippopotamus
• Browers- They feed on twigs and leaves eg antelopes, girraffes, goats

Carnivores.

These are mammals that feeds on flesh only. They include; lions, dogs, cats, leopard, etc

Adaptations of carnivores.

1. They have sharp and pointed incisiors for catching and holding their prey.
2. They have long pointed and strong canines for tearing off pieces of flesh from bone, they also penetrate flesh, holding and killing the prey.
3. They have ridged, flattened premolars and molars which fit well into each, saw like on both jaws for crushing bones and flesh into small portions.
4. They have strong scissor like carnassial teeth on both jaws for slicing into flesh and cracking bones.
5. They have well spaced teeth to prevent flesh from getting stuck between teeth.

Feeding Adaptations in Birds.

Grain eaters.

These are birds which feeds on grains or seeds.
They include; chicken, doves, Turkey, pigeons,Weaver bird and quelea birds. They have a strong, short, straight, thick, blunt and cone shaped beaks for picking grains.
Their claws are adapted to scratching.

Flesh eaters.

They are know us birds of prey.
They include Hawks, eagles, kites and falcons
They have short, thick, sharp and hooked(curved) beaks for cutting and tearing flesh.
They have a sharp eyesight for spotting their prey from far.
They have strong,sharp and curved claws called talons for holding and tearing their prey.

Nectar feeders.

They feed on nectars.
Examples include; sunbird and humming bird.
They have a long slender and slight curved beak for sucking nectarsfrom a flower.

Filter feeders.

These birds filters their foods from mud.
They include; ducks, sea gulls, swans, geese, pelican and flamingo.
They have a flat, broad, strong and serrated (v-shaped) beaksfor sieving or filtering their foods
Their feet are webbed.

Adaptations of Animals to Movement.

Reasons for movement.

1. To search for food (prey).
2. To search for shelter.
3. To escape from predators.
4. To search for favouble climatic condition.
5. To seek mates for reproduction.

Adaptations to Flying.

1. They have wings which has feathers to increase surface area for flapping against air.
2. They have hollow bones to make themlight so that they can float on air
3. They have a streamlined bodiesto enable them move quickly, smoothly and easily through air.

Adaptations to Swimming

1. They have fins(pelvic, pectoral, caudal, dorsal and anal fins) which help them to move in water.
2. They have swim bladder (air bladder) which help them to control their depth during swimming.
3. They have webbed feet which act as oarsfor propelling themin water.
4. They have streamlined body which help them to move smoothely in water.
5. They have scales pointing backwards and covered with slimy substance to minimise waterresistance

Adaptations to Hopping and Leaping.

They have a powerful hind legs to enable them move forward. Some have a
short fore legs and strong hind eg kangaroo. Some also have tails for balancing.
They include; amphibians, grasshopper, locust and kangaroos.

Signs of Ill Health in Livestock.

• Stunted or retarded growth.
• Loss of weight.
• Reduced yields.
• Rough coat.
• Coughing.
• Blood or worms in stool.
• Inactive.

Effects of Livestock Diseases.

• Lowers yields.
• Lowers quality of the product.
• Diseases can be passed to human being.
• Can cause death to animals

• Adaptations of plants to their environment.
  • Plants adapted to dry area.
  • Plants adapted to wet areas.
  • Adaptations to normal soil and water conditions.

Adaptations of plants to their environment.

Adaptations are mechanisms that enable a plant to survive in a habitat. Plants habitats include:-

• Dry areas
• Wet areas.
• Normal soil and water condition

Plants adapted to dry area.

Plants that are able to survive in dry area are called xerophytes.

Examples include: Cactus, acacia, euphorbia, baobab, sisal, marram grass, pricky pears, desert
shrubs, sun dune grass, jacaranda, thorn tree, cassava, casuarinas and candelabra.

Characteristics of xerophytes.

1. They have deep and widespread root system to obtain waterfrom a wider area.
2. They have stemsthat can store water; their stems are thick, fleshy and succulent. They also have waxy cuticle to reflect sunlight which may cause overheating.
3. They have needle-like leaves which reduces water loss by transpiration and evaporation.
4. Some have few leaves to reduce water losslike acacia.
5. Some shed leaves in dry seasonsto reduce water loss eg jacaranda.
6. Some fold their leaves to trap moisture for the plant eg sun dune grass.
7. Some are covered with a thick waxy cuticle which reduces water loss through evaporation eg sisal.
8. Some become inactive during dry seasons.
9. Some have sunken stomata that are hidden in small depression.
10. Some have reversed stomatal rhythm i.e. open their stomata during the night and close during the day.
11. Some have more stomata on the lowersurface than on the upper surface to reduce water loss through evaporation.

Plants adapted to wet areas.

They are called hydrophytes.

Most they grow in equatorial forests, swamps, marshes, lakes and rivers.

They include: water lily, butter cup, mangroves, bladderwort, water lettuce, duck weed, aquatic
ferns, rice plants and water hyacinth.

Adaptations of hydrophytes.

1. They have broad or wide flat leaves which enables them to float on water and encourages water loss by transpiration eg water lily
2. They have shallow roots which reduce the rate of absorption
3. They have leafy shoots which encourages water loss by transpiration, they also have more stomatas on the upper surface than on the lowersurface
4. They have numerous stomata which remain open to allow gas absorption for photosynthesis.
5. They have flexible stemsthat cannot be broken by water currents.
6. They have thin cuticle to encourage water loss through transpiration.
7. They have air sacs to enable them to float on water.
8. They have waxy and hairy leaf surface to prevent water from standing on the leaf surface.
9. They have floating flowers to allow for the cross pollination by small animals.

Adaptations to normal soil and water conditions.

Plants which grow in normal soil and water conditions are called mesophytes.

They includes maize, beans, potatoes and bananas.

Signs of unhealthy crops.

1. Leaf discoloration.
2. Stunted or stranded growth.
3. Curled leaves.
4. Spots or streaks
5. Wilting.

Effects of crop diseases.

1. Lower yields.
2. Reduces quality of produce.
3. Reducesincome or economic loss.

• Sexually Transmitted infections (STIs)

Sexually Transmitted Infections (STIs)

These are diseases which are passed from one person to another person through sexual contact.

They are also called sexual transmitted diseases (STDs)

NB: Genital herpes and HIV/AIDS are other STIs caused by virus.

• Fertilization
  • Types of Fertilization
  • Foetal Development.
• Excretion
  • Excretory Organs (SKIL)

Fertilization

Fertilization is the fusion or union of the nuclei of the ovum and the sperm in the
oviduct/fallopian tube.

Types of Fertilization.

There are two types of Fertilization that takes place in the female's body. Namely;

• Internal fertilization- Which takes place inside the female's body, mainly in human beings,
  birds and reptiles.
• External fertization - Which takes place outside the female's body, mainly amphibians and
  fish.

Process of Fertilization in human beings

During sexual intercourse/coitus/copulation, sperms are introduced in the vagina by the penis.

Sperms swim in the semen using their tails until they reach the oviduct where they meet a
mature ovum.

Many sperms surrounds the ovum but only one penetrates the ovum, the nuclei of the sperm
and the ovum fuse to form a Zygote

After fertilization a woman becomes pregnant and this is called conception. NB: The sperms
which do not penetrate the ovum are killed.

The zygote then undergo cell division, travels down to uterus and attaches itself on the uterine walls, this is called implantation

After implantation, the zygote is called embryo 

Foetal Development.

After implantation, the embryo develops a disc-shaped organ called placenta which joins the
embryo to the mother.

At 6weeks the embryo has formed most of the important body organs such as the
lips, nose, arms, ears, eyes, feet and toes.

At 8weeks(2months), the embryo is called foetus. The foetus is surrounded by the amnion which
contains a fluid called amniotic fluid.

Functions of the placenta

• Exchange of carbon dioxide and oxygen between the mother and the foetus.
• Supply food from the mother's blood to the foetus.
• Production of hormones that maintains pregnancy.
• Facilitates transfer of waste productsfrom the foetus to the mother's blood.

Functions of the umbilical cord.

• Joins the foetus to the placenta.
• It is a passage for oxygen, food and carbon dioxide.

Functions of the amniotic fluid.

• It acts as a shock absorber to protect the foetus against physical injuries.
• It keeps the foetus warm.
• It prevents the foetus from drying.
• It lubricates the foetus for easy movement.

NB: Gestation period takes nine months or 36 to 40weeks or 280days in human beings, this is
the period between conception and birth.

Signs of pregnancy.

• Menstruation stops.
• The breast becomes larger, tender and sensitive.
• Increased frequency of urination.
• Craving for some foods.
• In later stage, expectant mothers experience some slight backaches.
• Heartburns.
• The abdomen enlarges.
• Breathlessness,tiredness and increased pulse rate.
• Movement of the foetus is felt.
• Morning sickness or nausea.

Birth process.

It is also called parturition.

When the foetus is fully developed, the head faces downwards and is positioned directly above the
cervix.

Stages in the birth process.

• The uterus walls contract causing labor pain.
• The cervix widens.
• Amnion burst and amniotic fluid flows out of the vagina.
• The baby is pushed out through the vagina with the head first.
• Breathing is induced by pinching of patting the baby.
• The umbilical cord is tied and cut, this prevents loss of blood from the mother and the baby also separates the baby from the mother.
• The placenta is expelled from the body. The expelled placenta is called afterbirth.

Excretion

This is the removal of waste productsfrom the body.

Excretory Organs (SKIL)

There are 3 main excretory organs, namely;

• Skin
• Lungs
• Kidneys.

Waste products removed by these organs are;

• Excess water.
• Excess salt.
• Urea.
• Carbon dioxide.
• Lactic acid.

Water, salt, urea and lactic acid forms sweat

Water, urea and salt forms urine.

Order of urine.

Kidney----->Ureter----->Bladder----->Urethra.