CH6 specialised cells and tissues

Question 1

What is the order of organisation in multicellular organisms

Answer 1

Specialised cells, tissues, organs, organ systems, whole organism

Question 2

Erythrocytes

Answer 2

• flattened biconcave shape which increases SA:V
• no nuclei and few other organelles which increases volume for haemoglobin
• flexible so able to squeeze through narrow capillaries

Question 3

Neutrophils

Answer 3

• multi-lobed nucleus so easier to squeeze through small gaps to get to site of infection
• granular cytoplasm contains many lysosomes that contain enzymes used to attack pathogens

Question 4

Sperm cell

Answer 4

• tail or flagellum so are capable of movement
• contain many mitochondria to supply energy needed to swim
• acrosome contains digestive enzymes which are released to digest protective layers around ovum

Question 5

Palisade cell

Answer 5

• contain chloroplasts that can move within cytoplasm which absorb light for photosynthesis
• rectangular box shaped so can be closely packed to form a continuous layer
• thin cell walls
• large vacuole to maintain turgor pressure

Question 6

Root hair cells

Answer 6

• have long extensions which increase surface area

Question 7

Guard cells

Answer 7

• cell wall thicker on inside so cell doesn’t change shape symmetrically as volume changes
• when high levels of water, guard cells become turgid, stomata open

Question 8

What are the four main categories of tissues in animals

Answer 8

• nervous
• epithelial
• muscle
• connective

Question 9

Squamous epithelium

Answer 9

• made of squamous epithelial cells
• thin which allows for rapid diffusion

Question 10

Ciliated epithelium

Answer 10

• made of ciliated epithelial cells
• have hair like structures called cilia that move in rhythmic manner
• causes mucus to be swept away from lungs
• goblet cells present which release mucus to trap unwanted particles in air

Question 11

Cartilage

Answer 11

• connective tissue
• contains fibres of elastin and collagen
• firm, flexible tissue composed of chondrocyte cells embedded in an extracellular matrix

Question 12

Muscle

Answer 12

• needs to be able to shorten in length to move bones
• skeletal muscle fibres contain myofibrils which contain contractile proteins

Question 13

What are the main tissues in plants

Answer 13

• epidermis tissue
• vascular tissue

Question 14

Epidermis

Answer 14

• single layer of closely packed cells covering surface of plants
• usually covered by waxy cuticle to prevent water loss
• stomata present

Question 15

Xylem

Answer 15

• responsible for transport of water and minerals through plants
• tissue composed of vessel elements which are elongated dead cells
• walls of cells are strengthened by lignin

Question 16

Phloem

Answer 16

• responsible for transport of organic nutrients
• composed of columns of sieve tube cells separated by perforated walls called sieve plates