B1 Cell biology

Question 1

Meaning of Eukaryotic cells

Answer 1

Have a cell membrane,
cytoplasm and genetic material (DNA) enclosed in a nucleus.
Animal and plant cells are eukaryotic cells

Question 2

Meaning of Prokaryotic cells

Answer 2

These are smaller than eukaryotic cells. The genetic material is not enclosed in a nucleus. The DNA is a single loop and there may be one or more rings of DNA called plasmids.

Question 3

Function of Sperm

Answer 3

To fertilize an egg
Long tail to swim towards the egg.
Acrosome in the head containing enzymes to digest the egg cell membrane.
Large number of mitochondria in the mid section to release energy for movement.

Question 4

Function of Nerve

Answer 4

Function to carry electric signals

Long to carry signals long distances.
Branched connections to connect to other nerve cells and form a network around the body.

Question 5

Function of Muscle

Answer 5

Contain a large number of mitochondria to release energy from respiration for movement.
Long so that there is enough space to contract.

Question 6

Function of Root Hair cell

Answer 6

Function is to absorb water and minerals from the soil.

Hair like projections to increase the surface area. (Note that root hair cells have no chloroplasts this is because they do not need them as they are in the soil)

Question 7

Function of Xylem

Answer 7

Function is to carry water and minerals in plants.

Water and minerals flow from the roots towards the leaves out of the stomata only in one direction in a process called TRANSPIRATION.

Question 8

Function of Pholem

Answer 8

Function is to carry glucose around the plant.

phloem tubes made of living tissue.
Glucose in solution moves from the leaves to growth and storage tissues through the phloem in a process called TRANSLOCATION.

Question 9

What is Xylem

Answer 9

Water and minerals flow from the roots towards the leaves out of the stomata only in one direction in a process called Transpiration

Question 10

What is Pholem

Answer 10

Glucose and other sugars move from the leaves to growth and storage tissues through the phloem in a process called Transloaction

Question 11

What is the Magnification Equation

Answer 11

Magnification (M) = Size of image (I) / real size of the object (A)

Question 12

Magnification Equation rearranged (calculating image size)

Answer 12

Size of Image (I) = Magnification (M) x Real size of object (A)

Question 13

Magnification Equation (calculating real size of an object)

Answer 13

Real size of object (A) = Size of image(I) / Magnification(M)

Question 14

What does a nucleus of a cell contain

Answer 14

Contains the instructions for making proteins and new cells

Question 15

What are chromosomes?

Answer 15

Coiled strands of DNA molecules.

Question 16

what is DNA

Answer 16

A genetic material found in the nucleus that codes for proteins.

Question 17

What is Diffusion

Answer 17

Diffusion is the movement of particles for an area of high concentration to a area with lower concentration this does not require energy

This does not require any energy

Question 18

What is Osmosis

Answer 18

The movement of water molecules across a partially permeable membrane from an area of a high water concentration to a region of a lower water concentration.

This does not require energy

Question 19

What is Active Transport

Answer 19

Active transport is the movement of particles from a low concentration gradient to a high concentration gradient. Using energy - The energy is provided by respiration.

Requires energy

Question 20

The larger the difference in concentration …

Answer 20

The faster the rate of diffusion

Question 21

What are some Factors which effect rate of diffusion

Answer 21

Temperature,concentration gradient and the surface area of the membrane

Question 22

Some adaptations of Small intestines

Answer 22

Internal surface is covered in millions of
folds called villi.

Villi increase the surface area.

Villi have a very good blood supply. This
maintains the concentration gradient.

Question 23

Some Adaptations of the lungs

Answer 23

Lungs contain millions of tiny air sacs called alveoli.

Alveoli increase the surface area.

Alveoli have a very good blood supply. This maintains the concentration gradient.

Question 24

Some Adaptation of fish

Answer 24

Gill filaments increase the surface area

Gill filaments are covered in Lammella

Question 25

Adaptations of root hair cells

Answer 25

Root surfaces is covered in millions of root hair cells.

Root hair cells increase the surface area

Absorbs water and minerals

Question 26

Some Adaptations of leaves ‘

Answer 26

Large surface area to absorb more light

Xylem and Phloem support the leaves to transport water and minerals

Chlorophyll absorbs sunlight for photosynthesis.

Question 27

Hypertonic,isotonic and hypotinic meanings

Answer 27

Hyper tonic= more concentrated solution than in the cells

Isotonic= same concentration as the solution in the cell

Hypotonic= more dilute than inside of the cell