B1 Biology Top 41

Question 1

What is the independent variable?

Answer 1

This is the variable that you control. It is changed to see how the dependant variable will change.

Question 2

What is the dependant variable?

Answer 2

The dependant variable is the variable you measure as an outcome of the experiment.

Question 3

What are three differences between a prokaryote and a eukaryote?

Answer 3

Prokaryote - Smaller, no nucleus, older, simpler, no membrane bound organelles, DNA located in cytoplasm
Eukaryote - Bigger, nucleus, younger, complex, membrane bound organelles, DNA located in nucleus

Question 4

What are three organelles found in a plant cells not in animal cells?

Answer 4

Cell wall, chloroplasts, vacuole

Question 5

What is the function of the mitochondria?

Answer 5

For respiration

Question 6

What is the function of the ribosomes?

Answer 6

For protein

Question 7

What are three differences between a bacteria and animal cell?

Answer 7

Bacteria - Smaller, no nucleus, older, simpler, no membrane bound organelles, DNA located in cytoplasm
Animal cell - Bigger, nucleus, younger, complex, membrane bound organelles, DNA located in nucleus

Question 8

What is the formula for calculating magnification when using a microscope?

Answer 8

magnification = size of image/actual size

Question 9

What are two advantages of an electron microscope?

Answer 9

Better resolution, Better magnification

Question 10

How many μm are in a mm?

Answer 10

1000

Question 11

What are two adaptations for a sperm cell?

Answer 11

Tail to swim to the egg, lots of mitochondria for energy

Question 12

What are two adaptations of a root hair cell?

Answer 12

Big surface are to move water into cell, large vacuole to store water

Question 13

What is the role of the xylem?

Answer 13

To transport water and nutrients around the plant

Question 14

What is the role of the phloem?

Answer 14

Transports food around the plant that has been made from photosynthesis

Question 15

What does the term differentiation mean?

Answer 15

When a stem cell turns into a specialised cell

Question 16

What is a stem cell?

Answer 16

Undifferentiated cells that have the potential to develop into many different types of cells

Question 17

What are two ways stem cells can treat disease?

Answer 17

Can replace organs, grow new organs

Question 18

Why are some people against the idea of using stem cells to treat disease?

Answer 18

That it could be potential life and can’t consent to the operation

Question 19

Where are stem cell found in plants?

Answer 19

The tips of roots and shoots

Question 20

How many chromosomes are in a normal human cell?

Answer 20

46 (23 pairs)

Question 21

How do prokaryotic cell reproduce?

Answer 21

Binary fission

Question 22

A bacterium divides once every 20mins. How may will there be after 3 hours?

Answer 22

512

Question 23

A bacterium divides once every 15mins. How may will there be after 1hr and 30mins?

Answer 23

64

Question 24

What is a gene?

Answer 24

The short end of a chromosome that carries the DNA

Question 25

What are the two parts of the cell cycle?

Answer 25

Mitosis, growth and DNA replication

Question 26

What is mitosis used for?

Answer 26

Growth and repair

Question 27

What can you say about the cells produced by mitosis?

Answer 27

They are identical

Question 28

How do you describe mitosis in simple terms?

Answer 28

The chromosomes copy, line up at the centre of the cell and then divide. Protein fibres pull them apart then the cell membrane and cytoplasm divide.

Question 29

What is diffusion?

Answer 29

Movement of particles from areas of high concentration to areas of low concentration (down a concentration gradient)

Question 30

What are three factors that affect diffusion?

Answer 30

Temperature, surface area, distance, concentration gradient

Question 31

What are four features of exchange surfaces to make them more effective?

Answer 31

Thin so short diffusion pathway, large surface area, good blood supply, moist for gas to dissolve

Question 32

What are four adaptations of the villi?

Answer 32

Large surface area, moist for gas to dissolve, good blood supply, thin so short diffusion pathway

Question 33

What are four adaptations to speed up diffusion?

Answer 33

Stomata allows gases to diffuse to maintain concentration gradient, thin so short diffusion pathway, air spaces and flattened shape increase surface area, moist for gas to dissolve

Question 34

What is osmosis?

Answer 34

Movement of water particles through a partially permeable membrane from an area of high water concentration to area of low water concentration.

Question 35

What is the formula for calculating percentage change in mass?

Answer 35

change in mass/original × 100

Question 36

What happens to a plant cell when it is placed in pure water and why?

Answer 36

Swells and becomes turgid as water moves in by osmosis, from high water concentration to low water concentration.

Question 37

What happens to a plant cell when it is placed in a concentrated solution and why?

Answer 37

Shrivels and becomes plasmolysis as water moves out by osmosis, from high water concentration to low water concentration.

Question 38

What is active transport?

Answer 38

Movement of substances from low to high concentration (against a concentration gradient)

Question 39

What does active transport require?

Answer 39

Energy from respiration

Question 40

What is an example of active transport in plants?

Answer 40

Absorbing minerals from soil

Question 41

What is an example of active transport in humans?

Answer 41

Absorbing substances such as glucose in small intestine or kidney