Cell structure and transport

Question 1

Oxygen will diffuse into the cell above, why? (1)

Answer 1

Because there is a high to low oxygen concentration

Question 2

For what process do cells use oxygen

Answer 2

Respiration

Question 3

How are these muscle cells adapted to release a lot of energy (2)

Answer 3

They contain many mitochondria for respiration

Question 4

Name the structure in the animal cell that contains genetic material

Answer 4

Nucleus

Question 5

What is osmosis

Answer 5

Osmosis is the movement of water particles
from a dilute to a more concentrated solution
through a semi permeable membrane.

Question 6

Explain how this plant root is adapted to absorb water (3)

Answer 6

There are many hairs
which gives a larger surface area
so there is more osmosis of water into the root

Question 7

Cells use respiration to release

Answer 7

Energy

Question 8

Describe function of mitochondria and explain why they are arranged around a filament near the tail of the sperm (3)

Answer 8

Energy released
near site of movement
so energy is available quickly as there is efficient arrangement

Question 9

Explain the significance of the Nucleus in determining the characteristics of the offspring (2)

Answer 9

Contains genes which contribute to half the genes to the offspring

Question 10

Name the process by which gases move in and out of the cell

Answer 10

Diffusion

Question 11

Describe the functions of muscle cells in walls of the stomach

Answer 11

They contract

to churn food

Question 12

Function of mitochondria (2)

Answer 12

Transfer energy for use by aerobic respiration

Question 13

Function of ribosome

Answer 13

To make proteins

Question 14

Why can’t ribosomes be seen through a light microscope?

Answer 14

Ribosomes are too small

Question 15

Why do epithelial cells have a faster rate of diffusion? (1)

Answer 15

It has a larger surface area

Question 16

Name enzyme produced by salivary glands

Answer 16

Carbhohydrase

Question 17

Define Hypertonic

Answer 17

Solution is more concentrated than the cell

Question 18

Define Hypotonic

Answer 18

Solution is less concentrated than the cell

Question 19

Word used to describe plant cells placed in a hypotonic solution

Answer 19

Turgid

Question 20

Word used to describe plant cells placed in a hypertonic solution(1)

Answer 20

Plasmolysed

Question 21

Red blood cells are placed in a hypotonic solution. Predict what will happen (4)

Answer 21

Water enters the cell by osmosis
the cells burst
as animal cells have no cell wall
and the cell wall prevents bursting

Question 22

The flagellum helps the cell to move through water. Scientists think that the flagellum and the light-sensitive spot work together to increase photosynthesis.
Suggest how this might happen. (2)

Answer 22

Light sensitive spot detects light and tells flagellum to move towards light

Question 23

Multicellular organisms often have complex structures, such as lungs, for gas exchange.
Explain why single-celled organisms, like algae, do not need complex structures for gas exchange. (3) (4 points needed)

Answer 23

Cell has a larger surface area to volume ratio
short diffusion distance
diffusion by cell membrane is sufficient
flow of water maintains concentration gradient

Question 24

Name one food molecule absorbed into epithelial cells by active transport

Answer 24

Glucose

Question 25

Why is it necessary to absorb some food molecules by active transport? (1)

Answer 25

Active transport is against a concentration gradient

Question 26

Suggest why epithelial cells have many mitochondria (2)

Answer 26

Active transport is requires energy from respiration

Question 27

Name one substance that plants absorb by active transport

Answer 27

Minerals

Question 28

Diffusion is an important process in animals and plants.
The movement of many substances into and out of cells occurs by diffusion.
Describe why diffusion is important to animals and plants.
In your answer you should refer to:
• animals
• plants
• examples of the diffusion of named substances.

Answer 28

Diffusion is important to take in substances for use in cell processes
and removes waste products from cell processes
Animal use diffusion for gas exchange to take in O2 in and let CO2 out. This happens down a concentration gradient in the lungs.

Plants use diffusion for gas exchange to take in CO2 and let O2 out. This happens down a concentration gradient on the stomata

Question 29

Define down a concentration gradient

Answer 29

High to low concentration

Question 30

Define against a concentration gradient

Answer 30

Low to high concentration

Question 31

. In fish and chip shops, potatoes are cut into chips several hours before they are cooked.
The mass of water in the chips must be kept constant during this time.
To keep the water in the chips constant, the chips are kept in sodium chloride solution
Describe how you would use the apparatus and materials shown in the drawing to find the concentration of sodium chloride in which to keep the chips so that the mass of water in the chips remains constant. (6)
You should include:
• the measurements you would make
• how you would make the investigation a fair test.

Answer 31

use of scalpel to cut chips to same dimensions
use of range of sodium chloride concentrations
use of forceps to transfer chips
use of balance to measure mass of chips before immersion, record the results
use of balance to measure mass of chips after immersion, record the results
To make it a fair test make sure that the chips left in solutions for same length of time