Biology4 8D Microbes - unicellular organisms

Question 1

Which of the 5 different kingdoms contains cells without a nucleus?

Answer 1

The only cells without a nucleus are bacteria. Their DNA is loose DNA in the cytoplasm.

Question 2

What is the name for the cells with a nucleus?

Answer 2

The name for the cells with a nucleus is Eukaryote.

Question 3

Why does the pH of milk drop as it changes into yoghurt?

Answer 3

The pH drops as lactic acid is made by the microbes added to the milk. This makes the milk curdle and thicken as well as making the yoghurt taste sour.

Question 4

In a food chain the numbers decrease from one level to another. Can you explain why?

Answer 4

In a food chain the numbers decrease from one level to another there is less energy available for the next level of the food chain. The less energy available, the fewer organisms it can support.

Question 5

What are the stages in the growth of a population of a microbes?

Answer 5

The stages in the growth of a population of a microbe are slow increase in number, fast increase in number, maximum population, death.

Question 6

What is the role of the nucleus in a cell?

Answer 6

The nucleus is the organelle which contains DNA and so controls the cell.

Question 7

What is the name for the cells without a nucleus?

Answer 7

The name for the cells without a nucleus is Prokaryote.

Question 8

What is the role of the cell wall in a cell?

Answer 8

The cell wall is the part of a cell which supports and protects the cell.

Question 9

Which 2 kingdoms contains multicellular organisms?

Answer 9

The 2 kingdoms which contains multicellular organisms are the plant and animal kingdom.

Question 10

Name a food made by a bacteria

Answer 10

An example of a food made by a bacteria is yoghurt.

Question 11

Why are decomposers important for an ecosystem.

Answer 11

They break down waste and recycle carbon.

Question 12

Why do multicellular organisms (plants and animals) need transport systems?

Answer 12

Multicellular organisms (plants and animals) need transport systems because it would take too long to deliver oxygen to tissues in the middle of your body by diffusion.

Question 13

What kind of respiration makes lactic acid?

Answer 13

Lactic acid is made by anaerobic respiration ( when no oxygen is available)

Question 14

What is the disadvantage of being unicellular?

Answer 14

The disadvantage of being unicellular is that the cell cannot get too large as it depends on diffusion for the movement of food and oxygen into the cell.

Question 15

What does a bacterial cell use its flagellum for?

Answer 15

A bacterial cell use its flagellum (plural flagella) to move itself around.

Question 16

When you make bread you put it in warm place to prove and increase in size. Why does the bread rise?

Answer 16

The microbes (yeast - a fungus) releases carbon dioxide

Question 17

What is the role of the chloroplast in a cell?

Answer 17

The chloroplast is the part of a cell which makes food/glucose by photosynthesis. It contains the green pigment chlorophyll which absorbs light energy..

Question 18

What is the role of the ribosomes in a cell?

Answer 18

The ribosomes are the pace in a cell where proteins are made.

Question 19

Name a kingdom that contains unicellular organisms that never contain mitochondria or a nucleus

Answer 19

A kingdom that contains organisms made of cells that never have mitochondria or a nucleus is the bacteria kingdom.

Question 20

What is the role of the mitochondrion in a cell?

Answer 20

The mitochondrion is the organelle where aerobic respiration takes place.

Question 21

What 3 resources do microbes need to survive?

Answer 21

To survive microbes need warmth, moisture, and food (such as glucose)

Question 22

Name a kingdom that contains organisms made of cells that never have cell walls.

Answer 22

A kingdom that contains organisms made of cells that never have cell walls is the animal kingdom. The other 4 kingdoms all have cell walls.

Question 23

What is the role of the cell surface membrane in a cell?

Answer 23

The cell surface membrane wall is the part of a cell which controls what enters and leaves the cell

Question 24

What do we mean by a producer in an ecosystem?

Answer 24

A producer in an ecosystem is one which can photosynthesise.

Question 25

Name a kingdom that contains unicellular organisms that can have chloroplasts.

Answer 25

A kingdom that contains unicellular organisms that can have chloroplasts is the protoctists. it cannot be plants as these are multicellular!

Question 26

Which microbes produce alcohol?

Answer 26

The microbes which produce alcohol are fungi such as yeast. They do this when they respire anaerobivally. (without oxygen). it is called fermentation.

Question 27

Yeast cells reproduce asexually. How do they do this?

Answer 27

Yeast cells increase by budding. Eventually the bud breaks off the parent microbe and becomes an individual. It will be an exact genetic copy

Question 28

Glucose is an organic compound. Give the name of one other organic compound

Answer 28

Any kind of food group such as protein, starch, fat, lipid, oil, carbohydrate

Question 29

Why do the numbers of microbes in a petri dish of agar reach a peak and then drop?

Answer 29

The numbers of microbes in a petri dish of agar reach a peak and then drop because they run out of food and die.

Question 30

What is asexual reproduction?

Answer 30

Asexual reproduction does not need a second parent or sperm or egg cells (gametes) . It makes an exact copy of the parent (called a clone)

Question 31

What is a decomposer?

Answer 31

An organism that breaks down/feeds on dead organisms and animal wastes.

Question 32

Name a food made by a bacteria

Answer 32

Examples of food made by bacteria include yoghurt, cheese and vinegar.

Question 33

A virus is not a living thing. State three things that a virus cannot do for itself.

Answer 33

Three of: move, reproduce, sense things, grow, excrete, respire, get nutrition

Question 34

The 5 different kinds of cells are sorted into 5 kingdoms of living organisms. Name them (in any order)

Answer 34

Plants, Animals, Fungi, Bacteria, Protoctists

Question 35

What is the chemical reaction for anaerobic respiration in bacteria?

Hint: we use these bacteria to make yoghurt.

Answer 35

Bacteria use a type of anaerobic respiration to ferment milk: glucose → lactic acid

Question 36

What is the difference between unicellular and multicellular organisms?

Answer 36

The difference between unicellular and multicellular organisms is that unicellular organisms are made of only 1 cell and multicellular organisms are made of many cells.

Question 37

How do bacteria and fungi feed?

Answer 37

Bacteria and fungi feed by releasing enzymes into their surroundings to digest large organic molecules. The digested molecules are then absorbed.

Question 38

Name a food made using yeast

Answer 38

Examples of food made using yeast iare bread and beer or wine.

Question 39

How does drying foods stop them going off? .

Answer 39

Microbes need moisture to survive. They cannot feed and grow without it.

Question 40

Which 2 kingdoms contain cells which can photosynthesise?

Answer 40

The 2 kingdoms contain cells which can photosynthesise are plant and algal kingdoms.

Question 41

What shape is the graph of population growth of microbes?

Answer 41

The shape of the graph of population growth of a microbe is an exponential.curve.

Question 42

What is the chemical reaction for fermentation?

Answer 42

glucose → carbon dioxide + ethanol (alcohol)

Question 43

Bacteria and Yeast are in different kingdoms. State 2 differences between bacteria and yeast

Answer 43

Yeast have mitochondria, bacteria do not. Yeast cells have a nucleus, bacteria have a circular chromosome loose in the cytoplasm.

Question 44

What is the chemical reaction for photosynthesis?

Which microbes can do this?

Answer 44

Some protoctists can photosynthesise:

carbon dioxide + water → glucose + oxygen

Question 45

How do protoctists move?

Answer 45

Some protoctists move using pseudopods (extending their cell membranes into arms) while others use cilia and others use flagella.

Question 46

Whyis the carbon cycle important?

Answer 46

Because it shows how all the processes involved in moving carbon around the environment are linked. This gives us information on the causes and solutions to the issue of global warming.