humans and the environment Flashcards
ecology
the study of the relationships among living organisms and their physical environment
species
a group of organisms that can reproduce with one another in nature and produce fertile offspring
population
A group of individuals of the same species within a community
community
an interacting group of various species in a shared/ common location
ecosystem
a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life
biomes
an area classified according to the species that live in that location
biodiversity
the variety of all living things and their interactions
abiotic factors in an ecosystem and their effects on the community
refers to the non-living components of an ecosystem. They include physical and chemical factors such as temperature, light, water availability, soil composition, air quality, humidity, pH
directly influence the distribution, abundance, and behaviour of organisms within the community
E.G: temperature affects the metabolic rates and physiological functions of organisms, while water availability determines the productivity and survival of plants and animals
biotic factors in an ecosystem and their effects on the community
refers to the living components of an ecosystem. They include all the organisms present, including plants, animals, fungi, bacteria, and other microorganisms
they play roles as producers, consumers, and decomposers, influencing energy flow, nutrient cycling, and food webs
temperature, rainfall and vegetation of tundra
extremely cold temperatures, low precipitation, and unique vegetation adapted to withstand the harsh environment
temperature, rainfall and vegetation of coniferous forest
cold temperatures, moderate to high levels of precipitation, and cone-bearing evergreen trees, such as pine, spruce, fir, and cedar
temperature, rainfall and vegetation of broadleaf forest
distinct seasons, (warm summers and cold winters), moderate to high levels of annual precipitation, and a diverse range of trees that shed their leaves during the winter season (maple, oak, birch)
temperature, rainfall and vegetation of tropical forest
high temperatures, extremely high precipitation levels, dense, lush vegetation (extremely biologically diverse ecosystem)
temperature, rainfall and vegetation of grassland
warm temperatures. Depends on the grassland, but they can achieve either low or moderate levels of rainfall, and are dominated by species of grasses and herbaceous plants
temperature, rainfall and vegetation of desert
during the day its extremely warm but during the night it can be below freezing, with extremely low levels of rainfall, drought-tolerant plant species like cacti
succession
a natural process that occurs over time as an ecosystem transitions from a barren or disturbed area, such as bare rock, to a more complex and mature community, such as a forest
changes in succession
1) pioneer species start to colonise the area (barren rock)
2) pioneer species establish themselves and modify the abiotic conditions. (more conductive things for plants to grow)
3) progression of succession, shrubs and fast-growing tree species begin to dominate the landscape
4) stable and diverse ecosystem has been established
factors that alter the progress of succession
soil conditions, climate, human interference, natural disasters
process of photosynthesis
1) Plants absorb CO2 through the stomata
2) Plants absorb water through the soil in the roots
3) Absorption of light through chlorophyll
word and symbol equation of photosynthesis
carbon dioxide + water + light energy → glucose + oxygen
6CO2 + 6H2O + light energy → C6H12O6 + 6O2
word equation for aerobic respiration
glucose + oxygen → carbon dioxide + water + energy
identify the different types of cells in a leaf (palisade mesophyll, spongy mesophyll, lower epidermis, upper epidermis and guard cells)
palisade mesophyll: contains high numbers of chloroplasts; responsible for most of the photosynthesis in the leaf
spongy mesophyll: arrangement allows for gas exchange, facilitating the movement of gases such (CO2 and O2)
lower epidermis: helps protect the leaf
upper epidermis: helps protect the leaf
guard cells: can change shape to open or close the stomata, regulating the movement of gases (CO2 and O2) and water vapour
materials that glucose can be converted into after it has been made by photosynthesis
starch, cellulose, lipids
how light intensity affects the rate of photosynthesis
as light intensity increases, the rate of photosynthesis increases as more energy is available for the process (can be too much light as CO2 and temp becomes limiting factors)
how CO2 concentration affects the rate of photosynthesis
as CO2 levels increase, the rate of photosynthesis increases
how temperature affects the rate of photosynthesis
different enzymes involved in the process have specific temperature ranges at which they work optimally. As temperature increases, so does the rate of photosynthesis, up to an optimal temperature
why are mineral ions needed in order to make components such as proteins, DNA and chlorophyll (due to their chemical compositions)
proteins: are composed of amino acids, so mineral ions provide essential elements that are incorporated into amino acids
DNA: is composed of nucleotides, which consist of a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base. Mineral ions are necessary for the formation of DNA molecules
chlorophyll: has a complex structure with a porphyrin ring at the core. The porphyrin ring contains a central magnesium (Mg) ion, which enables chlorophyll to absorb light energy and initiate the process of photosynthesis. Without magnesium, chlorophyll cannot function effectively, leading to reduced photosynthetic activity
life cycle of a plant
germination: under favourable conditions of moisture, temperature, and light, the seed absorbs water and swells (grows root)
growth and development: the germinating seed develops into a seedling, characterised by the emergence of leaves. the seedling undergoes further growth, developing a root system and establishing itself in the soil
flower formation: during the reproductive phase, the plant produces flowers
pollination: transfer of pollen grains from the anther (the male part of the flower) to the stigma (the female part of the flower). it’s through pollination that the male gametes are delivered to the female gametes for fertilization
fertilisation: a pollen grain lands on the stigma and forms a pollen tube that grows down through the style to reach the ovary (fusion of male and female cells)
fruit formation: ovary of the flower develops into a fruit
process of germination and state the conditions necessary (water, oxygen, warmth)
germination is when a seed develops into a plant
water: softens the seed coat, initiates enzyme activity, and allows for the uptake of nutrients
oxygen: necessary for cellular respiration
warmth: stimulates enzymatic activity and speeds up metabolic processes
define productivity
refers to the rate at which organisms within an ecosystem produce biomass or energy through photosynthesis or other metabolic processes
flow of energy in a food chain
flow of energy in a food chain refers to the transfer of energy from one organism to another as they consume and are consumed by each other
(see book)
why is energy lost between trophic levels and how does this limit its length
heat loss during metabolism: organisms use energy they obtain from food for their own processes like respiration, growth, and reproduction. energy is converted into heat and released into the environment. this heat loss is unavoidable and represents a loss of energy from the system
inefficiency in energy transfer: energy transfer between trophic levels isn’t 100% efficient. When an organism consumes another, only a fraction of the consumed energy is converted into biomass and made available for the next trophic level
herbivore
an organism that mostly feeds on plants
carnivore
an organism that mostly eats meat, or the flesh of animals
producer
any kind of green plant
primary consumer
make up the second trophic level. they’re also called herbivores. they eat primary producers—plants or algae—and nothing else
secondary consumer
eat primary consumers. secondary consumers are mostly carnivores
tertiary consumer
carnivores that feed largely on the primary consumers and secondary consumers. carnivores that feed on other carnivores are considered tertiary consumers
sigmoid population growth curve + limits to the population at each stage (lag, exponential and stationary)
also known as the S-shaped curve, represents the growth pattern of a population over time
lag phase: pop is small and experiences slow growth. occurs when a population is introduced into a new environment or after a period of decline (adapting to it)
exponential phase: pop. experiences rapid growth. rate of reproduction exceeds the rate of mortality, resulting in an accelerating increase in population size (abundant resources and favourable environmental conditions)
stationary phase: population stabilises + reaches a constant size. limit to the pop. in the stationary phase is determined by the carrying capacity of the environment. the availability of resources becomes limited, leading to competition for resources, and increased predation
carrying capacity
refers to the maximum number of individuals of a species that a particular environment can sustainably support over a given period
