Judicial precedent or decisions is a process which is followed by the judges to take the decision. In Judicial precedent, the decision is taken by following the similar cases happened in the past. So judicial decision is based on the principle of stare decisis i.e. “stand by the decision already made”.

• Robert Hooke was the scientist who gave Hooke’s law.
• Hooke’s law states that within the elastic limit, stress developed is directly proportional to the strain produced in a body.
• Consider a scenario where we apply external force to the body. As a result stress develops in the body due to this stress there will be a strain produced in the body which implies that there will be some deformation in the body.
• Because of stress, strain is produced.
• According to Hooke’s law, if strain increases the stress will increase and vice-versa.
• The Hooke’s law is applicable to all elastic substances.
• It does not apply to plastic deformation.

According to the Law of Diminishing Marginal Utility, marginal utility of a good diminishes as an individual consumes more units of a good. In other words, as a consumer takes more units of a good, the extra utility or satisfaction that he derives from an extra unit of the good goes on falling.

Characteristics of Porifera:

(i) They are sessile, sedentary, and marine except one group that lives in fresh water. These are non-motile animals attached to some solid support.

(ii) Simplest multicellular, diploblastic animals.

(iii) The body design involves minimal differentiation and division into tissues.

(iv) Asymmetrical or radically symmetrical.

Example: Sponges and Sycon.

Characteristics of Annelida:

(i) Body triploblastic, bilaterally symmetrical, soft, elongated, vermiform and cylindrical or dorsoventrally flattened.

(ii) Exoskeleton absent; body is covered by a thin cuticle.

(iii) Alimentary canal is tube-like, complete and extends straight from mouth to ****.

(iv) Reproduction is by sexual means. Sexes may be united (hermaphroditic) or separate.

(v) True coelomate animals with closed blood vascular system. Coelom allows true organs to be packaged in the body structure.

(vi) They live in a variety of habitats. Mostly aquatic, marine or fresh water. Some are terrestrial, burrowing in tubes, some free-living forms.

Example: Nereis (sand worm) and Hirudinaria (leech).

• Echinodermata:

Characteristics of Echinodermata:

(i) Simple animals may be a star like, spherical or elongate.

(ii) Body triploblastic, coelomate, unsegmented and radially symmetrical.

(iii) Body lacks head but has oral and aboral surfaces. Oral surface of the body has five radial areas called ambulacra.

(iv) Body wall is covered with spiny hard calcareous (calcium carbonate) plates (ossicles) that forms a rigid or flexible endoskeleton.

Example: Echinus (sea urchin) and Asterias (star fish).

Female reproductive system consists of two large ovaries which lie on the lateral side of the 2nd to 6th abdominal segments. Each ovary consists of 8 ovarioles containing beaded strings of developing ova. Each ovary gives rise to oviduct. Two oviducts from either side join to form common oviduct which open into ******. ****** opens into the genital chamber. A pair of spermatheca present in the 6th segment open into genital chamber.

During copulation, sperm is transferred through spematophores. After copulation, female cockroach secretes a capsule called ootheca which contains the fertilised eggs. Ootheca is a brownish capsule of 8 mm length with fertilised eggs. At about 10 oothecae are laid by the female in the cracks and crevices found in the house. Each ootheca has at about 14 to 16 eggs. Development of cockroach includes nymph stage. Nymph moults around 13 times to transform into an adult.

Nuclear pores are tiny holes present in the nuclear membrane of the nucleus. They are formed by the fusion of two nuclear membranes.
These holes allow specific substances to be transferred into a cell and out from it. They allow molecules such as RNA and proteins to move in both directions, between the nucleus and the cytoplasm.

The limbic system is a set of structures in the brain that controls emotion, memories and arousal. It contains regions that detect fear, control bodily functions and perceive sensory information (among other things). The structures and interacting areas of the limbic system are involved in motivation, emotion, learning, and memory. The limbic system is where the subcortical structures meet the cerebral cortex.

The inner ear contains vestibular apparatus that helps maintain the body’s balance. It consists of three semi-circular canals and the otolith organ which consists of the saccule and utricle, responsible for maintaining the body’s balance and posture.

Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. ... The cells in vascular tissue are typically long and slender. Vascular tissue transports water, minerals, and sugars to different parts of the plant. Vascular tissue is made of two specialized conducting tissues: xylem and phloem. Xylem tissue transports water and nutrients from the roots to different parts of the plant, and also plays a role in structural support in the stem.