Specialised cells

Question 1

Name the basic structure of a palisade mesophyll cell found in a plant

Answer 1

• Cell wall
• Cell membrane
• Cytoplasm
• Nucleus
• Vacuole
• Chloroplast

Question 2

Name the basic structure of a root hair cell

Answer 2

• Cell membrane
• Cell wall
• Vacuole
• Root hair
• Cytoplasm
• Nucleus

Question 3

Name the basic structure of a sperm cell

Answer 3

• Head
• Acrosome
• Nucleus
• Neck
• Middle piece
• Mitochondrian (spiral shape)
• Plasma membrane
• Undulipodium

Question 4

Name the basic structure of the egg cell

Answer 4

• Corona radiata
• Nucleus
• Cytoplasm
• Zona pelluccida

Question 5

Name the basic structure of the white blood cell

Answer 5

• Neutrophil
• Multi-loped nucleus
• Granulated cytoplasm

Question 6

Turgor …

Answer 6

Rigidity of plant cells due to pressure of cell contents on the cell wall.

Question 7

Water potential …

Answer 7

The tendency of a cell to draw in water from outside by

osmosis.

Question 8

Gamete …

Answer 8

One set of chromosomes compared to two sets in the parent cells.

Question 9

Pathogen …

Answer 9

A microorganism that can cause disease.

Question 10

Haemoglobin …

Answer 10

Protein molecule in red blood cells. It carries oxygen from the lungs to other parts of the body and carbon dioxide back to the lungs.

Question 11

Name the basic structure of the red blood cell

Answer 11

• Cytoplasm containing haeoglobin

Question 12

Describe the function of the palisade mesophyll cell

Answer 12

The chloroplasts are able to absorb a large amount of
light for photosynthesis. They also move around in the cytoplasm in order to maximise the amount of light absorbed. These cells are closely packed together and form a continuous layer in the leaf. Palisade cells are surrounded by a plasma membrane and a cell wall made of cellulose. This helps to protect the cell and keep it rigid. They also have a large vacuole to maintain turgor pressure (the plasma membrane pushes against the cell wall of plant to maintain its rigid structure).

Question 13

Describe the function of the root hair cell

Answer 13

These cells are found at a plant’s roots, near the growing tip. They have long hair-like extensions called root hairs. The root hairs increase the surface area of the cell to maximise the movement of water and minerals from the soil into the plant root. The cells have thin cellulose walls and a vacuole containing cell sap with a low water potential. This encourages the movement of water into the cell.

Question 14

Describe the function of the sperm cell

Answer 14

Sperm cells are male gametes in animals. They have a tail-like structure called a undulipodium so they can move. They also contain many mitochondria to supply the energy needed for this movement. In human sperm, the mid-piece of the tail is 7 μm long and the end is approximately 40 μm in length. The sperm head is 3 μm wide and 4 μm long. It is made up of an acrosome, which contains digestive enzymes. These enzymes are released when the sperm meets the egg, to digest the protective layer and allow the sperm to penetrate. The sperm’s function is to deliver genetic information to the egg cell or ovum (female gamete). This is fertilisation.

Question 15

Describe the function of the egg cell

Answer 15

Egg cells, or ova, are the female gametes in animals . An egg cell is one of the largest cells in the human body, and is approximately 0.12 mm in diameter. It contains a nucleus which houses the genetic material. The zona pellucida is the outer protective layer/membrane of the egg. Attached to this is the corona radiata, which consists of two or three layers. Its function is to supply proteins needed by the fertilised egg cell.

Question 16

Describe the function of the red blood cell

Answer 16

Red blood cells or erythrocytes are a bi-concave shape (where both sides concaveinwards). This increases the surface area to volume ratio of an erythrocyte. They are flexible so that they can squeeze through narrow blood capillaries. Their function is to transport oxygen around the body. In mammals, erythrocytes do not have a nucleus or other organelles. This increases space for the haemoglobin molecules inside the cell that carry oxygen.

Question 17

Describe the function of the white blood cell

Answer 17

Neutrophils are a type of white blood cell and they play an important role in the immune system. They have multi-lobed nuclei, which enables them to squeeze though small gaps when travelling to the site of infection. The cytoplasm holds lysosomes that contain enzymes that are used to digest pathogens that are ingested by the neurophil.