Biology

Question 1

Osmosis

Answer 1

Water moves from where the solute is in low concentration to where the solute is in high concentration through a semipermeable membrane.

Question 2

Diffusion

Answer 2

Movement of a substance from high concentration to low concentration [no membrane involved, free movement of substances - particles spread out]

Question 3

Active transport

Answer 3

Requires the input of energy. Moves molecules from an area with low concentration to an area with high concentration.

Question 4

Passive transport

Answer 4

Does not require energy to move substances across cell membranes. Moves molecules from a high concentration to a low concentration.

Question 5

Endocytosis vs Exocytosis

Answer 5

Endocytosis is when a large particle has to be moved into a cell and the cell membrane changes it’s shape to surround the particle.
Exocytosis is when substances are transported to the external environment of the cell.

Question 6

Structural adaptation

Answer 6

physical features or characteristics that have helped them survive in an environment eg. root structure, leaves, fur, scales.

Question 7

Physiological adaptations

Answer 7

Internal features of an organism that helps them survive. Eg. poison leaves, snake and spider venom.

Question 8

Behavioural adaptations

Answer 8

Something a plant or animal does in order to survive. Eg. growing towards the sunlight, roots growing down, migration, hibernation.

Question 9

Stomata structure and function

Answer 9

Miniature pores called stoma that are surrounded by a pair of guard cells. It allows the plant to take in carbon dioxide and let out oxygen by regulating gas exchange between the plant and environment.

Question 10

Antibiotic resistance

Answer 10

Through mutation and selection, bacteria can develop defense mechanisms against antibiotics.

Question 11

Cane toad evolution

Answer 11

No natural predators for cane toads causing them to adapt to the environment.

Question 12

Darwins observations

Answer 12

He discovered various different species of finches that varied from island to island. In his observations, he realised that the shape of their beaks were different according to the food they consume

Question 13

Evolutionary theory evidence

Answer 13

Fossils and similarities between related organisms were used by Darwin. Scientists today use DNA testing.

Question 14

Eukaryotic cells - what is it

Answer 14

can be single celled or multicellular, contains a nucleus surrounded by a membrane.

Question 15

Prokaryotic cells - what is it

Answer 15

Single celled organism, no membrane-bound nucleus or membrane-bound organelles.

Question 16

Biotic

Answer 16

The living parts of an ecosystem such as plants, animals and bacteria

Question 17

Abiotic

Answer 17

The non living parts of an ecosystem such as water, soil and atmosphere

Question 18

Photosynthesis

Answer 18

The plant draws up water through the roots, the leaves take in carbon dioxide from the air, leaves trap energy from the sunlight, the plant uses the energy from the sunlight to turn water and carbon dioxide into oxygen, the plant uses oxygen for growth.

Question 19

Respiration

Answer 19

The transfer of oxygen from the outside environment to cells within tissues as well as the removal of carbon dioxide.

Question 20

Enzymes - how do they work and what affects their actions

Answer 20

They are protein molecules that control all metabolic reactions in living cells. Enzymes require particular conditions in order to work effectively (normal body temp).

Question 21

Transport systems in animals and plants

Answer 21

Plants - Uses xylem and phloem tissues for transportation of minerals and water.
Animals - The cells require a constant supply of nutrients and oxygen and the continual removal of waste products. A circulatory system is the most efficient way to achieve this. (use their blood to transport carbon dioxide and oxygen.)

Question 22

Xylem

Answer 22

Transports water and dissolved minerals upward through the plant, from the roots to the leaves.

Question 23

Phloem

Answer 23

Transport products of photosynthesis from the leaves, where they are produced, to the rest of the plant where they are either used or stored.

Question 24

Concurrent/countercurrent flow for gas exchange

Answer 24

Concurrent - Where the blood flows next to the medium (liquid) in the same direction. As they flow along the membrane, oxygen moves to equilibrium
Countercurrent - Blood flows in the opposite direction to water, next to the water that has given up less of its oxygen. This way, the blood absorbs more and more oxygen as it moves along

Question 25

Autotrophs vs heterotrophs

Answer 25

Autotrophs: an organism that can produce its own food using light, water, carbon dioxide or other chemicals.
Heterotrophs: an organism that eats other plants and animals for energy and nutrients.

Question 26

Convergent evolution

Answer 26

Distantly related organisms independently evolve similar traits to adapt to similar necessities.

Question 27

Divergent evolution

Answer 27

Two groups of the same species evolve different traits within those groups in order to accommodate for differing environmental pressures.

Question 28

Punctuated equilibrium

Answer 28

Evolution occurs through short bursts of intense speciation followed by long periods of no change.

Question 29

Kidney function

Answer 29

Removes waste from the blood, Regulates concentration of substances and Maintains homeostasis.

Question 30

Gas exchange in plant and animal cells

Answer 30

Plants: gas exchange takes place through the stomata. Plants take in carbon dioxide and release oxygen through the stomata
Animals: release carbon dioxide into the atmosphere and take up oxygen

Question 31

Thermoregulation

Answer 31

Maintains a steady internal body temp despite changes in the external condition

Question 32

Cell differentiation

Answer 32

Dividing cells change their functional or observable traits type.

Question 33

Comparative anatomy

Answer 33

This is the study of similar and different structures in an organism. An example is the similar bone structure in the forelimbs of cats, bats, whales and humans.
The three main structures include - homologous structure, analogous structure, vestigial structure

Question 34

Functions of a cell membrane

Answer 34

To protect the cell by acting as a barrier and to control the entry and exit of materials from cells.

Question 35

Mitochondria function

Answer 35

Produces energy through cellular respiration. Sugars, fats and other fuels are consumed in the presence of oxygen to generate energy.

Question 36

Relative dating

Answer 36

This is used to put fossils in a chronological sequence. It provides evidence to determine which fossil is younger or older, depending on what layer it is found in. The specific age of the fossil cannot be determined.

Question 37

Absolute dating

Answer 37

This allows us to determine the actual age of a fossil using elements that are present in the fossil.