Biology Flashcards Preview

KS3 science end of year examssss > Biology > Flashcards

Flashcards in Biology Deck (33)
Loading flashcards...

Describe the magnification and resolving power of the light microscope

magnify up to about x2000, and has a resolving power of 200nm


Describe the magnification and resolving power of the electron microscope

magnify up to about x2 000 000, and has a resolving power of 0.2nm


how do you calculate magnification?

magnification = size of image divided by size of real object


What 5 features do all animal cells have?

a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes


What 7 features do all plant and algae cells have?

a nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, cellulose cell wall and a permanent vacuole filled with sap


What 3 features do Eukaryotic cells have?

cell membrane, cytoplasm and genetic material enclosed in a nucleus


What 3 features do Prokaryotic cells have?

cytoplasm and a cell membrane surrounded by a cell wall. The genetic material isn't in a distinct nucleus. It forms a single DNA loop. Prokaryotes may contain more extra small rings of DNA called plasmids


Are bacteria prokaryotic or Eukaryotic?

Bacteria are all prokaryotes.


Name 3 examples of specialised animal cells

nerve cells, muscle cells and sperm cells


Name 4 examples of specialised plant cells

root hair cells, photosynthetic cells, xylem cells and phloem cells


Animal and plant cells may be specialised to function within..

a tissue, an organ, an organ system or whole organisms


What kind of reaction is photosynthesis?

Photosynthesis is an endothermic reaction.


What is the word equation photosynthesis?

carbon dioxide + water -> glucose +oxygen


What is the symbol equation for photosynthesis?

6CO(2) +6H(2)O -> C(6)H(12)O(6) + 6O(2)


How are leaves adapted to allow the maximum amount of photosynthesis?

Most leaves are broad, giving them a big surface area, most leaves are thin so diffusion distances for the gases are short, they contain chlorophyll in the chloroplasts to absorb light, they have veins which bring plenty of water in the xylem to the cells of the leaves and remove the products of photosynthesis in the phloem, they have air spaces that allow Carbon dioxide to get to the cells, and oxygen to leave by diffusion, they have guard cells that openand close the stomata to regulate gas exchange.


What are the limiting factors of photosynthesis?

Photosynthesis may be affected by light intensity, temperature, level of CO(2) and the amount of chlorophyll


what do plant and algal cells use the glucose produced during photosynthesis for?

For respiration, to convert into insoluble starch for storage, to produce cellulose to strengthen cell walls, and to produce amino acids for protein synthesis .


What do plant and algal cells need nitrate ions for?

Plants and algal cells need nitrate ions absorbed from the soil or water to make the amino acids used to make proteins.


Why are Limiting factors important in the economics in greenhouses?

The economics are important to gain maximum rate of photosynthesis while still maintaining profit.


What kind of reaction is cellular respiration?

It is an exothermic reaction that occurs continuously in living cells.


What is the word equation for aerobic respiration?

glucose + oxygen = carbon dioxide +water (+ energy)


What is the symbol equation for aerobic respiration?

C(6)H(12)O(6) + O(2) -> CO(2) + H(2)O


What energy does the aerobic respiration supply?

All the energy needed for living processes


What is the energy transferred during respiration used for?

It is used to enable muscles to contract


Name three body responses to exercise.

An increase in heart rate, in the breathing rate and breathe volume/ glycogen stores in muscles are converted to glucose for cellular respiration/ the flow of oxygenated blood to the muscles increases.


Why do the responses to exercise act?

They act to increase the rate of supply of glucose and oxygen to the muscles and the rate of removal of CO(2) from the muscles.


When do muscles respire anaerobically?

If muscles work hard for a long time, they become fatigued and don't contract efficiently. If they don't get enough oxygen, they will respire anaerobically.


Describe anaerobic respiration

Anaerobic respiration is without oxygen, when this takes place in animal cells, glucose is broken down to form lactic acid.


Does anaerobic or aerobic respiration breakdown of glucose transfer less energy.

The anaerobic breakdown if glucose transfers less energy than aerobic respiration.


What happens after exercise where you have respired anaerobically?

Oxygen is still needed to break down the lactic acid that has built up/