SUMMARY NOTES Flashcards
1
Q
What are the five kingdoms of classification?
A
- Prokaryotae
- Protoctista
- Fungi
- Plantae
- Animalia
Each kingdom represents a major category of life forms with distinct characteristics.
2
Q
Define Prokaryotae.
A
Unicellular organisms with cell walls, no true nucleus, and lack membrane-bound organelles.
Example: TB bacterium.
3
Q
What is the defining feature of Protoctista?
A
Mostly unicellular, some simple multicellular organisms with a true nucleus and membrane-bound organelles.
Examples: Amoeba, Paramecium.
4
Q
What are the characteristics of Fungi?
A
- Mostly multicellular with hyphae
- Cells have walls with chitin
- Lack chlorophyll, reproduce by spores
- Feed by absorbing food
Example: Pin mould.
5
Q
Describe the Plantae kingdom.
A
- Multicellular with cell walls made of cellulose
- Contain chlorophyll, make food via photosynthesis
- Stationary
Example: Ferns.
6
Q
What are the characteristics of the Animalia kingdom?
A
- Multicellular
- No cell walls or chlorophyll
- Feed by ingesting food
- Most are capable of movement
Example: Mammals.
7
Q
What are Bryophytes?
A
- Simple stems and leaves
- Root-like structures called rhizoids
- Reproduce via spores
- Live in damp, shady areas
Examples: Moss, liverwort.
8
Q
What defines Ferns?
A
- Have true roots, stems, and leaves (fronds)
- Reproduce by producing spores on the underside of fronds
Examples: Breadfruit fern, maidenhair fern.
9
Q
What characterizes Conifers?
A
- Have proper roots, stems, and needle-shaped leaves
- Reproduce by producing seeds inside cones
Examples: Pine, fir.
10
Q
Define Monocotyledons.
A
- Long, narrow leaves with straight, parallel veins
- Seeds contain one cotyledon
- Flower parts in multiples of three
Examples: Sugar cane, guinea grass.
11
Q
What are the features of Dicotyledons?
A
- Broad leaves with a network of veins
- Seeds contain two cotyledons
- Flower parts in multiples of four or five
Examples: Pride of Barbados, flamboyant.
12
Q
Define Ecology.
A
The study of the interrelationships between living organisms and their environment.
This includes both biotic and abiotic factors.
13
Q
What are biotic factors?
A
Living components that influence an organism, such as predators, prey, competitors, and parasites.
They are part of the ecological environment.
14
Q
What are abiotic factors?
A
Non-living chemical and physical components that influence an organism, such as temperature and water.
They are essential for understanding an ecosystem.
15
Q
What is a habitat?
A
The place where an organism lives.
Example: The upper layers of soil for earthworms.
16
Q
Define a species.
A
A group of organisms with common ancestry that can interbreed to produce fertile offspring.
Species are fundamental units in biology.
17
Q
What is a population in ecological terms?
A
All members of a particular species living in a specific habitat.
Example: Sea urchins in a sea grass bed.
18
Q
What is a community in ecology?
A
All populations of different species living in the same habitat.
Example: A woodland community.
19
Q
Define an ecosystem.
A
A community of living organisms sharing an environment.
Ecosystems can be large or small.
20
Q
What is a niche?
A
The role or position of an organism within an ecosystem.
Example: An earthworm’s role in soil aeration.
21
Q
Fill in the blank: The study of the interrelationships between living organisms and their environment is called _______.
A
[Ecology]
22
Q
True or False: No two species can occupy the same ecological niche.
A
True
This is due to competition and resource allocation.
23
Q
What are producers in an ecosystem?
A
Organisms that manufacture organic substances using water, carbon dioxide, and energy from light or chemical reactions.
Examples include green plants and certain bacteria.
24
Q
Define consumers.
A
Animals that eat other organisms to obtain energy and nutrients.
They can be herbivores, carnivores, or omnivores.
25
What are decomposers?
Organisms that feed saprophytically on dead organisms to obtain energy, breaking down complex compounds into simpler ones.
## Footnote
Examples: Bacteria and fungi.
26
Fill in the blank: A food web is formed when many food chains _______.
[link together]
27
What is the primary objective of an ecological study?
To find out which species are present at the site and analyze their distribution and relative abundance.
## Footnote
It may also monitor population changes.
28
What is a quadrat?
A square frame used to study the distribution and abundance of plants and slow-moving animals in uniform ecosystems.
## Footnote
Typically sized at 0.5 m × 0.5 m or 1.0 m × 1.0 m.
29
Define the Capture-Recapture method.
A method used to estimate population sizes of moving animals by marking a sample and then recapturing another sample.
## Footnote
The total population size is estimated based on the proportion of marked individuals.
30
What does species density refer to?
The number of individuals of a species per unit area.
## Footnote
It is a key metric in ecological studies.
31
What are abiotic factors divided into?
* Soil
* Water
* Climate
## Footnote
Each category influences the habitat and organisms within it.
32
What is the significance of light intensity in an ecosystem?
It affects the distribution and growth of both plants and animals.
## Footnote
Organisms adapt to maximize light capture or reduce excess light exposure.
33
Fill in the blank: The waterproof skin with scales, gills for breathing, and fins for swimming are characteristics of _______.
[Fish]
34
What are the characteristics of Amphibians?
* Soft, moist skin without scales
* Live in both water and land
* Larvae have gills; adults have lungs
## Footnote
Examples: Frog, toad.
35
What is the role of wind in an ecosystem?
Essential for pollination and seed dispersal in plants and may influence migration in birds.
## Footnote
Wind patterns can affect species distribution.
36
Define salinity in aquatic environments.
The concentration of salt in the water.
## Footnote
Aquatic organisms are adapted to specific salinity levels.
37
What is dissolved oxygen's importance in aquatic ecosystems?
Aquatic organisms use it for respiration; low levels can lead to poor habitat conditions.
## Footnote
Moving water typically has higher oxygen levels.
38
What is the role of mould in ecosystems?
Decomposition of organic materials
## Footnote
Mould obtains nutrients by breaking down organic material.
39
Why do food chains typically not exceed four trophic levels?
Energy is lost at each trophic level, making insufficient energy available for higher levels
## Footnote
Most food chains consist of only four to five trophic levels.
40
What is a food web?
A network formed when many food chains link together.
41
List characteristics of predators.
* Speed
* Stealth
* Camouflage
* Poison to kill
42
List characteristics of prey.
* Camouflage
* Rapid responses
* Protective body covering
43
What is the ecological relationship where a predator feeds on its prey?
Predation
44
What is interdependence in ecosystems?
The reliance of living organisms on their environment for energy, food, space, shelter, and warmth.
45
Describe the interdependence of oxygen and carbon dioxide.
Living organisms release carbon dioxide and consume oxygen during respiration, while plants take in carbon dioxide and produce oxygen through photosynthesis.
46
What is symbiosis?
A close relationship between two organisms of different species.
47
Define parasitism.
A relationship where one organism (the parasite) lives off another organism (the host), causing harm.
48
What is commensalism?
A symbiotic relationship where one organism benefits, and the other is neither helped nor harmed.
49
Define mutualism.
A symbiotic relationship where both organisms benefit.
50
What is the primary source of energy in an ecosystem?
The Sun
51
What percentage of energy is typically transferred from one trophic level to the next?
About 10%
52
What are ecological pyramids?
Diagrams representing the number, biomass, and energy of organisms at each trophic level.
53
What is the carbon cycle?
The process of recycling carbon through various processes like respiration, photosynthesis, and combustion.
54
What are the basic building blocks of living organisms?
Cells
55
What type of organisms are multicellular?
Organisms made up of many cells, such as animals, plants, and fungi.
56
What is the function of the cell membrane?
Protects and provides shape; selectively permeable.
57
What is the role of mitochondria in a cell?
Site of cellular respiration and ATP production.
58
What is the function of chloroplasts?
Site of photosynthesis in plant cells.
59
Define diffusion.
Passive movement of particles from high concentration to low concentration until equilibrium is reached.
60
What are the types of diffusion?
* Simple Diffusion
* Facilitated Diffusion
* Dialysis
61
What is osmosis?
Movement of water molecules through a partially permeable membrane from higher to lower water concentration.
62
What is the significance of osmosis in plants?
Facilitates water movement from soil to roots and regulates stomatal opening.
63
What is active transport?
Movement of substances against their concentration gradient using energy (ATP).
64
What are specialized animal cells?
* Red Blood Cells
* Sperm Cells
* Egg Cells
* Nerve Cells
* Muscle Cells
* Ciliated Epithelial Cells
65
What are specialized plant cells?
* Palisade Cells
* Spongy Mesophyll Cells
* Guard Cells
* Xylem Cells
* Phloem Cells
* Root Hair Cells
66
What is the role of guard cells?
Control the opening and closing of stomata.
67
Define microbes.
Organisms that are very small or invisible to the naked eye.
68
What is the impact of temperature on diffusion?
Higher temperatures increase molecular movement.
69
What is diffusion?
The process essential for nutrient and gas exchange in both plants and animals.
70
What role does osmosis play in plant cells?
Maintains cell turgidity, crucial for structural support and overall plant health.
71
How does osmoregulation occur in humans?
Via the kidneys, regulating water and salt levels in the blood.
72
What is active transport?
The movement of particles from a region of lower concentration to a region of higher concentration using energy.
73
What energy source is required for active transport?
ATP, produced through cellular respiration.
74
In which organisms does active transport occur?
Only in living cells.
75
What is the significance of the surface area to volume ratio?
A larger surface area relative to volume facilitates quicker exchange rates.
76
What adaptations do specialized exchange surfaces have?
* Large surface area
* Thin surface
* Partially permeable
* Adaptations like long projections or folded membranes
77
What is photosynthesis?
The process by which green plants convert carbon dioxide and water into glucose using light energy.
78
What is the equation for photosynthesis?
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
79
What are the two main stages of photosynthesis?
* Light-dependent stage
* Light-independent (Dark) stage
80
What conditions are necessary for photosynthesis?
* Carbon dioxide
* Water
* Sunlight
* Chlorophyll
* Enzymes
* Suitable temperature (5°C - 40°C)
81
What is etiolation in plants?
The process where plants grow elongated, pale stems in search of light.
82
What are the two types of nutrition in living organisms?
* Autotrophic Nutrition
* Heterotrophic Nutrition
83
What is the difference between autotrophs and heterotrophs?
Autotrophs produce their own food; heterotrophs depend on other sources for food.
84
What is a balanced diet composed of?
* Carbohydrates
* Proteins
* Fats
* Vitamins
* Minerals
* Water
* Dietary fibre
85
What are the effects of malnutrition?
* Over-nutrition leads to obesity
* Under-nutrition causes deficiency diseases like kwashiorkor and marasmus
86
What is the Basal Metabolic Rate (BMR)?
The energy required to maintain basic body functions at rest.
87
What are the stages of digestion?
* Ingestion
* Digestion
* Absorption
* Assimilation
* Egestion
88
What is the main function of the liver?
Regulates blood glucose levels, produces bile, detoxifies blood, and stores vitamins and minerals.
89
What enzyme breaks down starch into maltose?
Amylase.
90
What is the role of bile in digestion?
Emulsifies fats, increasing the surface area for lipase to break down fats.
91
What happens to excess glucose in the body?
It can be converted to fat and stored in adipose tissue.
92
What are enzymes?
Biological catalysts that speed up chemical reactions in the body.
93
What factors affect enzyme activity?
* Temperature
* pH
94
What is the definition of respiration?
The process of breaking down glucose in the presence of oxygen to release energy.
95
What is the difference between inhaled and exhaled air?
Inhaled air: 21% oxygen, 0.04% carbon dioxide; Exhaled air: 16% oxygen, 4% carbon dioxide.
96
What is the primary role of energy in biological processes?
Energy is used to break down and build molecules, facilitate transport across cell membranes, and support processes like muscle contraction and nerve impulse transmission.
97
What happens to energy during biological processes?
A significant portion of energy is lost to the environment as heat, but the remainder is vital for sustaining biological functions.
98
Where does respiration occur and what does it involve?
Respiration occurs in humans and animals and involves breaking down glucose in the presence of oxygen to release energy.
99
What are the products of aerobic respiration?
The products are carbon dioxide, water, and energy (ATP).
100
What is the difference between aerobic and anaerobic respiration?
Aerobic respiration requires oxygen, while anaerobic respiration occurs without oxygen, producing lactic acid or ethanol.
101
What process do green plants use to convert sunlight into energy?
Photosynthesis.
102
What are the products of photosynthesis?
Glucose and oxygen.
103
How are respiration and photosynthesis linked?
Oxygen produced during photosynthesis is used in respiration by animals, while carbon dioxide produced in respiration is used in photosynthesis by plants.
104
What are spiracles in insects?
Air holes along the body sides that lead to tracheae, a system of air tubes.
105
How do fish extract oxygen from water?
Fish use gills to extract oxygen from water and expel carbon dioxide.
106
Fill in the blank: Gas exchange in small animals like flatworms occurs through their _______.
skin.
107
What is the function of lenticels in plants?
Gas exchange occurs through lenticels, which are small breaks in the bark.
108
What is the role of the upper epidermis in plant leaves?
Covered with a waxy cuticle to prevent water loss, allowing minimal gas exchange.
109
What is the function of palisade cells in leaves?
Contains chloroplasts for photosynthesis, absorbing light for food production.
110
How do capillaries function in the circulatory system?
Capillaries are one-cell-thick vessels where the exchange of gases, nutrients, and waste occurs between the blood and body tissues.
111
What are the components of the human circulatory system?
The heart, blood vessels (arteries, veins, capillaries), and blood.
112
What is the primary function of red blood cells (RBCs)?
Carry oxygen from the lungs to tissues and remove carbon dioxide.
113
What is the role of white blood cells (WBCs)?
Defend the body against infections.
114
What is the function of platelets in the blood?
Help in blood clotting, preventing excessive blood loss.
115
What is plasma in the context of blood composition?
The liquid portion of blood that carries dissolved substances such as carbon dioxide, waste, hormones, nutrients, and heat.
116
What are the two phases of the cardiac cycle?
Systole (contraction) and diastole (relaxation).
117
What is the difference between pulmonary and systemic circulation?
Pulmonary circulation carries blood from the heart to the lungs for gas exchange, while systemic circulation carries oxygenated blood from the heart to the rest of the body.
118
True or False: Veins have thicker walls than arteries.
False.
119
What is blood pressure measured by?
A sphygmomanometer.
120
Describe the role of phagocytes in the immune response.
Phagocytes engulf and digest pathogens.
121
What is natural immunity?
Immunity gained through exposure to pathogens.
122
What happens during blood clotting?
Platelets adhere to the site of damage and release chemicals that trigger the formation of a clot.
123
What do xylem vessels transport?
Water and minerals from the roots to the leaves.
124
What is transpiration in plants?
The process by which water evaporates from the leaves, driving the movement of water from the roots through the xylem.
125
Fill in the blank: Xerophytes have adaptations such as thick cuticles and _______ to minimize water loss.
deep roots.
126
What are the two types of growth movements in plants?
Growth movement in response to stimuli and locomotion in animals.
127
What are the main functions of the human skeleton?
* Protection
* Support
* Locomotion
* Blood formation
128
What is the role of the cerebrum in the brain?
Responsible for voluntary actions, sensory perception, and decision-making.
129
What is the definition of a reflex action?
An automatic, involuntary response to a stimulus.
130
What occurs during the process of germination?
* Absorption of water
* Breakdown of food stores
* Translocation of nutrients
131
What are the three main structures of a dicotyledonous seed?
* Seed coat
* Cotyledons
* Embryo
