Biology class 10 icse

Mutation

Sudden change in the structure or number of chromosomes

Law of dominance

Out of a pair of contrasting characters present together , only one will be able to express itself while the other remains suppressed

Law of segregation

Two members of a pair of factors separate during the formation of gametes

Law of independent assortment

The distribution of the alleles of one character into the gametes is independent of the distribution of the alleles of the other character.

Single character, different traits: monohybrid ratio

Phenotypic 3:1
Genotypic 1:2:1

Di hybrid ratio

Phenotypic 9:3:3:1
Genotypic very complex

Sex linked inheritance

Appearance of a trait which is due to the presence of allele exclusively either on X chromosome or Y chromosome

Allele

Alternative forms of a gene , occupying the same position on homologous chromosomes and affecting the same characteristic but in a different way.

Genotype

The set of genes present in the cells of an organism

Phenotype

The observable characteristic which is genetically controlled

Pedigree chart

A diagram showing the ancestral history of a group of related individuals.

Genes

The specific sequences of nucleotides on a chromosome that encode particular proteins which express in the form of some particular feature of the body.

Characteristic

Inheritable feature

Trait

Alternative forms of a character

Variations

Small differences among individuals

Heredity

Transmission of genetically based characteristics from parents to offspring

Homologous chromosomes

A pair of corresponding chromosomes of the same shape and size one from each parent.

Genome

Full complement of DNA

Homozygous

Having to similar alleles of the same gene at the Corresponding sites on homologous chromosomes

Evolution

It is a slow and continuous process whereby complex forms of life have emerged from simpler forms through millions of years.

Jean baptise de Lamarck

Inheritance of acquired characters

Charles Darwin

Theory of natural selection or Darwinism

Theory of inheritance of acquired characters

1. Use and disuse
2. Inheritance of acquired characters

Vestigial organs(examples)

Wisdom teeth, Vermiform appendix, Pinna

Vestigial organs

There are those organs that have ceased to be any use to the possessor but still persist generation after generation in a reduced from

Theory of natural selection

Over production, struggle for existence, variation, survival of the fittest

Speciation

Origin of new species by gradual modification

Classical example of natural selection

Biston bitularia

Father of evolution

Charles Darwin

Who gave man the scientific name Homo sapiens

Carl Linnaeus

Pre-human ancestor

Ramapithecus

Cranial capacity of Australopithecus

450-600 cm cube

Cranial capacity of Homo habilis

680-735 cm cube

Cranial capacity of homo erectus

800-1 125 cm cube

Cranial capacity of Neanderthal man

1450 cm cube

Cranial capacity of Cro-Magnon

1600 cm cube

First hormone to be discovered in plants

Auxins

Full form of IAA(Natural auxin)

Indole 3 acetic acid

Apical dominance

The phenomenon of the suppression of growth of lateral buds by apical buds

Parthenocarpy

Auxins can induce fruit formation without fertilisation in fruits like apples, tomatoes, bananas,etc.
Development of fruits without fertilisation

The most studied form of gibberellins

Ga3 Gibberellic acid

Only hormone which is gas at ordinary temperature

Ethylene

Growth retarding hormone

Abscisic acid

Tropic movements

Growth movements Occurring in response to unidirectional external stimuli in a plant part

World population day

11 July

Three great cultural revolution

Tool making , agricultural revolution, scientific industrial revolution

Population explosion

It refers to the rapid and a massive rise in the world population that has occured over the last few hundred years.

Reason for sharp rise in World human population

Better healthcare
Fewer deaths
Food shortage minimise pd
Improved nutrition
Large scale immunisation
Fewer infant deaths

Need for adopting control measures

Decreasing open spaces
Shrinking of forests
Increasing industrialisation
Increasing pollution
Rapid and intense shortage of drinking water

Factors responsible for population explosion in India

Illiteracy
Traditional beliefs
Mortality rate
Economic reasons
Religious and social customs
Desire for a male child
Lack of re-creation

Resource

Any substance, resource or organism which is used by humans for their welfare

Production of food rises by

Arithmetic progression

Population grows by

Geometrical progression

Sustainable

It means which can be continued with no ill effect on the availability of the required items

Sustainable development

It means the kind of development that meets the need of the present without compromising the ability of the future generation to meet their own needs.

Demography

Statistical study of human population

Population density

It is the number of individuals per square kilometre at any given time

Natality

It is the number of live births per thousand people of population per year

Mortality

It is the number of deaths per thousand of population per year

Growth rate of population

Difference between birth rate and death rate

Family welfare

Offices in hospitals where any help or advice about family planning is available free of cost

Full form of IUD

Intrauterine devices

Tubectomy

Female surgical method

Vasectomy

Male surgical method

Full form of MTP

Medical termination of pregnancy

Waste

Any unwanted or undesirable material resulting from industrial commercial mining and agricultural operations and from community activities.

Biodegradable waste

Those substances which can be broken down by microorganisms into harmless and non-toxic substances

Pollution

Addition of any such constituent to air water or land which deteriorates the natural quality of the environment.

Air-pollution

Degradation of the air-quality harmfully affecting the living organisms as well as certain objects

Types of air-pollution

Gaseous pollution
Particulate pollution

Main gaseous pollutant

Carbon dioxide
sulphur dioxide
carbon monoxide

Control for vehicular air-pollution

Greater use of compressed natural gas
Efficient engines
Lead free petrol
Good quality auto mobile fuels

Smog

Smoke released from various sources may get mixed with dust particles and small drops of fog to produce smog
Causes asthma and allergies

Brick kilns

Fire heated enclosures for making construction bricks

Water pollution

Any change in the water quality which makes it suitable for use by humans and by other living organisms

Sewage

Liquid waste from domestic activities
Consists of kitchen waste, toilet and other household waste water

Oil spills

Accidental discharges of petroleum and oceans or estuaries

Sources of oil spills

Overturned oil tankers
Offshore oil mining
Oil refineries

Sanitary landfill

Places where the wastes are dumped in a ground depression and covered with dirt every day

DDT

Dichloro di phenyl trichloroethane

Chief radiant pollutant

Iodine-131

Noise pollution

Any unpleasant sound interfering with one's hearing and concentration

Harmful effects of noise pollution

Interferes in communication
Lowers efficiency of work
Disturbs sleep and leads to nervous irritability
Prolonged noise can lead to deafness

Harmful effects of acid rain

Damage to vegetation by pollution of the soil
Erosion of ancient monuments statues by the acid reacting with the calcium
Decay of building material and paints

International ozone day

September 16

Harmful effects of water pollution

Several diseases like cholera jaundice typhoid

Effects of soil pollution

Pesticides used in agricultural farming may cause health problems

Objective of clean India movement

Eliminate open defecation
Clean the streets roads and infrastructure of the country citizen towns
Achieve efficient solid and liquid waste management systems
Establish an accountable mechanism of monitoring latrine use

Imbibition

Phenomenon bt which the living or dead plant cells abs of water by surface attraction

Diffusion

Free movement of molecules of a substance from the region of their higher concentration to the region of their lower concentration in the two are in a direct contact

Osmosis

Movement of water molecules from the region of higher concentration to the region of lower concentration through a semipermeable membrane

End osmosis

Inward diffusion of water
Swell up the cell

Exosmosis

Outward diffusion of water
Shrinkage of the cell

Osmotic pressure

The minimum pressure that must be exerted to prevent the passage of the pure solvent into the solution when the two are separated by a semipermeable membrane

Tonicity

Relative concentration of the solution is that deter mine the direction and extent of diffusion

Active transport

Passage of a substance from its lower to higher concentration using energy from the cell through a living cell membrane

Turgidity

When I sell reaches the state where it cannot accommodate any more water i.e. it is fully distended, it is called turgid and the condition is called turigidity

Turgor pressure

Pressure of the cell contents on the cell wall

Wall pressure

Pressure of the cell wall on the cell content

Plasmolysis

Contraction of cytoplasm from the cell wall caused due to the withdrawal of water when placed in a strong solution