4.1 Different kinds of living organisms called species.
In different species, their offspring might be hybrid.
In different species, they produce infertile offspring.
4.2
Differences between members of a species are called variations.
We can use frequency diagram to show to show the patterns of variation in a group.
4.3
Investigating variation
Using mean, median , mode and range
The range is spread of numbers , from the smallest to the largest.
4.4
Classifying plants
All the organisms that have green leaves can photosynthesize is called plants.
Organisms that can move around and eat other organisms are called animals.
The plant group and animal group are called kingdoms.
Mosses and Ferns use spores for reproduction.
Mosses and Ferns do not produce flowers.
Ferns have leaves called fronds.
Conifers reproduce using seeds.
Conifers often have tough and narrow leaves called needles.
Flowering plants and conifers reproduce using seeds.
Plants are divided into four major groups such as mosses, ferns, conifers and flowering plants.
4.5
Vertebrates are animals with backbones.
The skin of fish is covered with scales.
Fish breathe using gills.
Fishes lay eggs in the water.
Amphibians have four limbs.
Adults live on land and breath using lungs.
The tadpoles develop in water and breathe using gills.
Amphibians have smooth skin without scales.
Reptiles
Reptiles are vertebrates with scaly skins.
Reptiles laying eggs on land.
Birds
Vertebrates with wings, feather and beak.
Lay eggs on land.
Mammals
Human belongs to the group of mammals.
Vertebrates with hair.
Mammals reproduce to live young, which are fed on milk from the mother.
4.6 Invertebrates
Invertebrates are animals without backbones.
Molluscs
soft body, mascular foot
Annalids
earthworm
body are divided into rings
do not have legs but tiny bristles called chaetae
Arthropods(skeletons are outside of the body called exoskeleton)
Insects(locust)
six Jointed legs
body- head, thorax, abdomen one pair of antennae
Arachnids(spider)
eight jointed legs
do not have wings and antennae
Crustaceans(lobster)
tough/very hard exoskeleton
more than four pairs of jointed legs
two pairs of antennae
Myriapods(centipede)
Many pair of jointed legs
one pair of antennae