Living World-1 Flashcards

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1
Q

what is biology?

A

bios=life
logos=study
it is the story of life on earth

it is the science of life forms and living organisms

it is study of evolution of organisms on earth.

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2
Q

what is taxonomy

A

Anthropocentric approach to biology did not lead to much succes its main aim was human life .

Systematic and monumental description of life forms made human to
make a detailed system of identification, nomenclature and classification
of organisms i.e. Taxonomy

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3
Q

how are organisms related

A

All the organisms have been evolved by a very long and complex
process of evolution, so they all are related to each other by sharing of
some common genetic material but upto varying degrees.

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4
Q

what are characters defining living

A

non defining:
growth
reproduction

defining:
ability to sense and respond- consciousness
metabolism
self organise and interact(cellular organisation)

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5
Q

alll living organisms grow. give reason

A

Increase in mass and increase in number of individuals are twin
characters of growth.

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6
Q

different types of growth

A

indeterminate:
- organisms grows continuouslt lifelong.
-plants keep growing lifelong due to cell division in meristamatic cells. it is localised growth

determinate growth:
-organism grows only to a certain age, and then cell divison to replace old and worn out cells
-in animals( diffused growth)

in microorganisms, cells grow by cell division.this can be observed in ‘in vitro cultures’

intrinsi and extrinsic growth:
inntrinsic growth- growth occurs from inside in living orgs

extrinsic- growth occurs from outside in non living organisms. in mountains the no living materials depositsi on surface

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7
Q

what is reproduction? is it a deifning feature of life? why?

A

production of new progeny by a living organism possessing similar features to parents.

-> for unicellular organisms like amoeba and certain algae, growth and cell division are equivalent.

-> many living organisms do not reproduce for example, mule( hybrid of donkey and horse), worker bees( sterile female), infertile human coouple

so it is not defining feature of life

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8
Q

how do these organisms reproduce:
i) fungi
ii) fungi, protonema of mosses, filamentour algae,planaria

A

i) production of millions of asexual spores
ii) fragementation

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9
Q

what is metabolism

A

The sum total of all metabolic reactiosn occuring in the living system is metabolism. These reactions involve conversions and biochemical reacns.

catabolism= reduction reactions
anabolism=production reactions
catabolism<anabolism=+ve grwoth

catabolism>anabolism= -ve growth

catabolism= anabolism= death

all living organisms exhibit metabolism. it is a defining feature of growth

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10
Q

what ab reactions in test tube

A

The isolated metabolic reaction outside the body of an organism,
performed in a test tube (in-vitro) is neither living nor non living.
*These isolated reactions can not be regarded as living things, but they
are definitely living reactions because they are similar to the
reactions performing in our body.

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11
Q

what is consciousness?

A

ability to sense surroundings and respond to envirionemtnal stimuli which maybe chemical, physical or biological

All organisms from the prokaryotes to complex eukaryotes show
consciousness to environmental cues.
*Plants also sense and respond to external factors like light, water,
temperature, other organisms, pollutants etc.

Plants perform flowering in a particular season (photoperiodism)
*Some animals perform breeding in a particular season only (seasonal
breeders)

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12
Q

what is self- consciousness

A

When human is concerned a very high level of consciousness is found
in human because of our very well developed nervous system and
supreme level of skill of communication which is called self-
consciousness.

*Self-consciousness is thought to be present only in human.

*The brain dead coma patient who is supported by machines which
replace heart and lungs also has consciousness

*So it is living but it does not has self consciousness because it has lost
the co-ordination of organs of different body parts.

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13
Q

define living organism

A

Properties of tissues are not present in the constituent cells but arise
as a result of interactions among the constituent cells.

*Similarly, properties of cellular organelles are not present in the
molecular constituents of the organelle but arise as a result of
interactions among the molecular components comprising the
organelle.

*All the living phenomena are due to underlying interactions between
different components of an individual or organ or tissue or cell.

*Living organisms are self replicating, evolving, and self regulating
interactive system capable of responding to external stimuli.
Adaptations and homeostasis( thermoregulation and osmoregulation) are also very important characters of
livings.

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