things i dont understand - biology

why can small and polar molecules dissuse through bi-layer

because if they are small enough, as they can pass between phospholipids.

what is a result of a pitutary gland unable to secrete thyroid stimulating hormone

an underactive thyroid

role of the chloroplast

site of photosynthesis

why is chloroplast structure important for their role

the chlorophyll captures sunlight to increase photosynthesis

role of the mitochondria

site of aerobic respiration

why is the structure of the mitochondria important for its role

inner folds of cristae increase surface area for production of ATP

how does a mutation in the p53 gene cause cancer

the gene normaly regulates the cell cycle to prevent tumor, however if a mutation occurs, the cells can continue replicating as the p53 gene cannot initiate apoptosis

similarites between mitosis and binary fission

both produce genetically identical cells

both undergo cytokinesis

why are aquaporins important

provide additional channels in the membrane to allow water to leave faster to enter the blood stream

role of the liver in terms of small intestine

the live produces bile which stores fats in the body, though digestion bile breaks into smaller pieces (fats) which are absorbed into the blood stream

how does fighting over mate influence gene pool

individuals with attributes that help them win mates will pass their stronger traits on meaning that the strong alleles will become more common in the gene pool

heterozygote advantage

provides higher genetic diversity with two alleles

what happens when a person shivers

heat is generated by cellular respiration occuring in muscle cells

if the gall bladder was removed what effect would it have on the body

bile is no longer stored and concentrated, instead flowing continuously into the small intestine, which can make fat digestion less efficient

what happens if the thyroid gland was removed from the body

stops the production of thyroid hormones, slowing metabolism and requiring lifelong hormone replacement medication.

what happens if part of the stomach was removed

educes food storage and can affect digestion and nutrient absorption

functions of the tounge that are important for digestion

bolus (clump of food) → tongue directs the food down the oesophagus 

tongue also physically compressing and breaking down food 

describe the walls of the xylem

thick, strengthened walls containing lignin, which provides support, has dead cell walls

optimal pH of the stomach

2

integrity

- doing the right thing when no one is looking

- honest reporting of results/sources

respect

- considering welfare/autotomy/culture

- protect those with diminished capacity

beneficence

- maximise benefits to other people

- doing good

justice

- fairness

- equal access/distribution to resources/earnings

non-maleficence

- doing no harm

- avoiding actions that will lead to harmful consequences