specialised animal cells/ tissues

Question 1

specialised cell

Answer 1

cell that has adapted to specific functions

Question 2

tissue

Answer 2

group of interconnected cells that perform a similar function (specialised cells grouped together)

Question 3

organ

Answer 3

different types of tissues (groups of cells) working together

Question 4

adaptations of red blood cell

Answer 4

-flattened biconcave shape
-increased space for haemoglobin
-squeeze through narrow vessels
-no nucleus and few organelles
-increased surface area for exchange
-flexible

Question 5

adaptations of a white blood cell (phagocytes)

Answer 5

-multi-lobed (nucleus that is divided into multiple distinct lobes or segments)
-lysosomes containing enzymes to break down pathogens
-granular cytoplasm
-easier to change shape and squeeze through small gaps

Question 6

what is a white blood cell also known as

Answer 6

phagocytes known as neutrophils

Question 7

what are red blood cells also known as

Answer 7

erythrocytes

Question 8

adaptations of the sperm cell

Answer 8

-digest zona pellucida layer on ovum to enable access for nucleus
-ATP provides energy for undulipodium to move
-many mitochondria
-acrosome (specialised lysosome) containing digestive enzymes
-haploid nucleus
-locomotion (ability to swim) through liquid

Question 9

diffrentiation

Answer 9

-start life as a single, undifferentiated cell called zygote (stem cell)
-embryo forms after many cell divisions
-embryonic cells differentiate

Question 10

how do embryonic cells differentiate

Answer 10

-certain genes are switched off and other genes may be expressed more

Question 11

examples of how a cell may differentiate

Answer 11

-proportion of organelles differ
-shape of cell changes
-contents of cell changes

Question 12

what are epithelial cells

Answer 12

-a lining found on both outside and inside the body e.g. lining intestines and skin

Question 13

characteristics of epithelial cells

Answer 13

-made up almost entirely of cells
-no blood vessels within epithelial tissue (receive nutrients from tissue fluid in underlying connective tissue)
-short cell cycles so that they can replace damaged/worn tissue

Question 14

types of epithelium

Answer 14

-squamous (pavement) - flat, 1 cell thick, present when rapid diffusion is necessary such as across the alveoli and capillary walls

-ciliated - hair like cilia, line trachea causing mucus to be swept away from the lungs

Question 15

what cells release mucus which trap pathogens and prevent entry to alveoli

Answer 15

goblet cells

Question 16

what is cartilage an example of

Answer 16

a type of connective tissue

Question 17

what does connective tissue consist of and whats its function

Answer 17

-non living extracellular matrix containing proteins (collagen and elastin) and polysaccharides
-separates living cells with tissue and enables to withstand forces such as weight

Question 18

cartilage

Answer 18

-firm, flexible tissue made up of chondrocytes embedded in a matrix

Question 19

3 types of cartilage

Answer 19

-hyaline (covers end of bonds)
-fibrous (discs between vertebrae and knee joint)
-elastic (outer ear and epiglottis- flap that covers larynx when swallowing)

Question 20

muscle tissue adaptations

Answer 20

-well vascularised
-elongated
-contain special organelles called myofilaments which allow muscle tissue to contract

Question 21

what are myofilaments made up of

Answer 21

2 proteins: actin and myosin

Question 22

3 types of muscle tissue

Answer 22

-skeletal- when contact, causes bones to move, joined to bone by tendons
-cardiac- make up walls of heart and allow it to pump blood
-smooth- propels substances along tracts e.g. in the uterus