Y9 - Term 1 - Biology

Question 1

Define ecology

Answer 1

How organisms interact with each other and their environment. E.g - energy movement through a food web

Question 2

Define environment

Answer 2

Consists of all the factors in an organism’s surroundings that affect its chances of survival. E.g - forest

Question 3

Define habitat

Answer 3

The natural environment or home of a plant or animal, providing it with the necessary elements like food, water, shelter and space to survive. E.g - ocean

Question 4

Define community

Answer 4

All different populations of organisms. E.g - forest of trees and undergrowth plants

Question 5

Define ecosystem

Answer 5

A biological community of interacting organisms and their physical environment - consist of physical surroundings, living and non-living factors that make up the environment. E.g - grassland

Question 6

Define abiotic

Answer 6

A non-living part of an ecosystem that shapes its environment.

Question 7

Define biotic

Answer 7

A real organism and it is living.

Question 8

What are the conditions for a biotic factor?

Answer 8

Symbiosis, competition, predation, mutualism, parasitism and commensal.

Question 9

What are the conditions for a abiotic factor?

Answer 9

Water, temperature, fire, light, soil type and gas levels.

Question 10

An example and a definition of ectothermic animals.

Answer 10

Any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface. E.g snakes

Question 11

An example and a definition of endothermic animals.

Answer 11

Those that maintain a constant body temperature independent of the environment. E.g birds

Question 12

Classifies structural adaptations.

Answer 12

It is a body part that helps an organism to survive. E.g bats wings for flying

Question 13

Classifies behavioral adaptations.

Answer 13

Features an organism habitat, action or way of life that helps it survive. E.g animals come out at night to ovoi

Question 14

Classifies functional adaptations.

Answer 14

Features of the way an organism’s body works. E.g heart beating faster when you excises

Question 15

How dose an adaptation increases an organism’s chance of survival and reproduction?

Answer 15

Providing an organism with a better ability to obtain resources, defend against threats, and reproduce in its environment.

Question 16

Define produces

Answer 16

Producers are organisms that make food Produces use photosynthesis to make energy for the plant Glucose is used to make all the other materials in a plants needs - protein, fats and vitamins - glucose is often turned into starch and then stored for later use

Question 17

Define consumers.

Answer 17

Food was originally made by a producer.

Question 18

Define herbivore.

Answer 18

Feeds on producers. E.g koalas

Question 19

Define carnivores.

Answer 19

Feed on herbivores. E.g fish

Question 20

Define scavangers.

Answer 20

Consumes carrion (dead flesh). E.g crows

Question 21

Define detritivore.

Answer 21

Consume detritus (small particles of dead plants & animals)

Question 22

Define decomposer.

Answer 22

Break down dead organisms

Question 23

Define parasites.

Answer 23

Live & feed on other organisms.

Question 24

Define food chain.

Answer 24

A series of organisms through which energy and nutrients are transferred from one to another in an ecosystem.

Question 25

Define food web.

Answer 25

Illustrates the multiple feeding relationships and energy flows that occur when organisms consume more than one type of food or are eaten by more than one type of predator.

Question 26

Describe how food webs are constructed.

Answer 26

A network of interconnected food chains that show how energy and nutrients move through an ecosystem.

Question 27

What makes an ecosystem sustainable?

Answer 27

Means that an ecosystem has the ability to maintain suitable living conditions for the community Needs . Supply of necessary substances for survival and growth . Input of energy . Wide range of species

Question 28

Describe how a food chain is constructed.

Answer 28

Starts with a producer, and typically ending at an apex predator, detritivore, or decomposer.

Question 29

What is the word equation for photosynthesis?

Answer 29

carbon dioxide + water + light energy → glucose + oxygen.

Question 30

What is biomass?

Answer 30

Biomass is the total mass of living organisms in a specific area or ecosystem.

Question 31

Define biodiversity

Answer 31

Biodiversity refers to the number of different species in an ecosystem and the population of each species *If an ecosystem is biodiverse then it has large numbers of many different species with a range of different characteristics

Question 32

Explain energy flow in a food chain.

Answer 32

The food materials that an organism has used for energy are not available to the organism that eats it. The original source of energy is the producers getting energy from the sun.

Question 33

What is the trophic level?

Answer 33

It is the stages in a food chain and web.

Question 34

How can bushfires, drought and flooding can affect ecosystems?

Answer 34

They are all natural impacts on ecosystems Destroying vegetation, altering soil structure, disrupting water cycles, reducing food sources for animals, and altering species composition, often leading to declines in biodiversity and impacting the overall health of the environment

Question 35

Explain how habitat destruction, introduced species, chemical pesticides, chemical pollution and overcropping can affect ecosystems.

Answer 35

Destruction, intoduced species, chemical

Question 36

Explain the need to coordination and control in the human body.

Answer 36

The coordinated function of body systems provides cells with the requirements for life and maintains humans as functioning organisms  for humans this involves the nervous system  thus, the nervous system coordinates the complex assortment of organ systems, organs and tissues

Question 37

Recall the structure of the human nervous system.

Answer 37

divided into the central nervous system (CNS), comprising the brain and spinal cord, and the peripheral nervous system (PNS), which includes all other nerves connecting the CNS to the rest of the body.

Question 38

Recall the types of neurons.

Answer 38

Motor Neurons * Carry messages from the CNS to effectors * Effectors are muscles or glands that put the messages into effect Sensory Neurons * Carry messages from cells in sense organs to the brain and spinal cord

Question 39

Explain the structure of a neuron.

Answer 39

Dendrites These are branching, tree-like structures that extend from the cell body. They receive signals from other neurons or sensory receptors. Cell body * Contains the nucleus Dendrites * Branch out from the cell body * Receive messages from other nerve cells Axon * Sends nerve impulses in one direction away from the cell body Axon terminals * Pass the message to the next neuron

Question 40

Explain how a nerve impulse is transmitted.

Answer 40

1 * Nerve impulse reaches axon terminal at end of the axon 2 * A chemical called a neurotransmitter is released into the space between neurons which is called a synapse 3 * Neurotransmitter carries the message from the axon of one neuron to the dendrite of the next neuron 4 * Dendrite receives the chemical message and sends off an electrical signal

Question 41

Recall the parts of the brain and describe their roles.

Answer 41

Cerebrum Responsible for: * Higher intellectual functions * Controls conscious thought * Controls voluntary movement * Receives sensory messages from the body 1. Left cerebral hemisphere * Controls the right side of the body * Language and logical thinking 2. Right cerebral hemisphere * Controls the left side of the body * Creative and emotional Cerebellum Location: Base of the cerebrum * Responsible for coordination and movement/balance Brain Stem (Medulla) Controls the body’s vital functions * Breathing, blood pressure, heart rate

Question 42

What is the somatic nerval system?

Answer 42

Has both motor and sensory nerves Collect information from the surroundings through sensory organs Coordinate movement of the body Sensory organs are receptors – special organs or tissues that have nerve endings that detect changes in the environment called stimuli Changes stimulate nerve endings to send messages to your brain Skin, hearing, light, smell and taste are the sensory organs

Question 43

What is the autonomic nervous system?

Answer 43

The autonomic nervous system breaks down into the Sympathetic nervous system and the Parasympathetic nervous system Sympathetic Nervous System * Speeds up functions of the body and make it work more efficiently * Prepares your body for emergencies Parasympathetic Nervous System * Slows everything down * This is the system in control when you are resting

Question 44

What are the different types of respecters and their functions?

Answer 44

Mechanoreceptors Mechanoreceptors are specialized sensory receptors that detect and convert mechanical stimuli, like touch, pressure, vibration, and sound, into electrical signals, which are then transmitted to the central nervous system. Photoreceptors Photoreceptors, specifically rods and cones, are specialized light-detecting cells in the retina that convert light into electrical signals, enabling vision. Thermoreceptors Thermoreceptors, specialized sensory neurons, detect temperature changes, with different types responding to cold or warmth, and play a crucial role in maintaining body temperature homeostasis. Chemoreceptors Chemoreceptors are specialized sensory cells that detect chemical changes in the body

Question 45

Describe the stimulus-response pathway

Answer 45

1. Receptors stimulate sensory nerves 2. Sensory nerves send a message to the brain 3. The brain works out a response and sends a message along motor nerves 4. Motor nerves stimulate effectors

Question 46

Define reflex action.

Answer 46

A reflex action is a quick, automatic response that protects the body from danger A reflex action does not involve the conscious part of the brain

Question 47

Draw a reflex arch. touching something hot

Answer 47

A reflex arc is the nerve pathway within a reflex action.

Question 48

Describe the role of the hypothalamus and pituitary gland in the endocrine system.

Answer 48

Homeostasis is the maintenance of a constant internal environment – the conditions inside our body must be very carefully controlled if the body is to function effectively Checks the internal environment of the body Links the nervous system and the endocrine system Controls: - Body temperature - Rate of metabolism - Water content Pituitary Gland Responds to the hypothalamus by secreting other hormones or producing less of hormones Controls the activities of other endocrine glands

Question 49

Describe the role and action of hormones and provide examples of the main hormones.

Answer 49

Produced in very small amounts To reach all body cells, how would the hormones travel? Specific à act only on particular cells called target cells Some hormones like estrogen take longer to act while others like adrenalin take 2 seconds and act fast.

Question 50

Define homeostasis.

Answer 50

Homeostasis is the process of maintaining a constant internal environment

Question 51

Describe how Homeostasis affects blood sugar.

Answer 51

Homeostasis, the maintenance of a stable internal environment, relies on feedback systems to regulate temperature, water balance, and blood sugar. Negative feedback loops, where a change triggers a response that counteracts the initial change, are crucial for these processes. Hight blood sugar pancreases releases insulin, that causes the liver and muscles to take the sugars from the blood and turn it to glycogen, than stored into the liver. Low blood sugar pancreas detects the change, it releases the hormone glycogan, back to glucose and released into the blood.

Question 52

What is the 10% rule?

Answer 52

Only 10% is carried onto the next tropic level. If a producer has 1000kg the primary consumer gets 100kg of energy transfered to them.

Question 53

Define parasympathetic

Answer 53

Parasympathetic makes you calm

Question 54

Define sympathetic

Answer 54

fight or flight alert of your surroundings