bio

Question 1

name the 7 characteristics of life

Answer 1

reproduction
evolution
homeostasis
respond to stimuli
display heredity through DNA
require energy
mdae of cells

Question 2

describe the negative feedback loop for when the body is too hot

Answer 2

cause: exercise
change: increased body temp > 38C
receptor: thermoreceptor in skin & blood vessels
control centre: hypothalamus in brain
effectors: sweat glands and muscles in blood vessels
changes: evaporate sweat and blood vessels expand (vasodialation)
back to normal 37.5-38C

Question 3

describe the negative feedback loop for when the body is too cold

Answer 3

cause: living in canada
change: body temp < 37.5
receptor: thermoreceptor
control centre: hypothalamus in brain
effectors: blood vessel muscles and skeletal muscles
change: vasoconstriction, shiver (make heat)
back to a normal 37.5-38C

Question 4

define homeostasis

Answer 4

maintaining a constant stable internal environment, despite internal and external changes.

Question 5

list 5 body functions controlled by homeostasis

Answer 5

osmoregulation, glucoregulation, thermoregulation, breathing, heart rate

Question 6

define the 3 types of mechanisms used for homeostasis

Answer 6

receptor- detects change
control center- processes data from the receptor and decides what to do
effector- puts change into effect as directed by the control center

Question 7

define negative feedback

Answer 7

when the body detects a change and puts something into effect that reverts the change (ex. too hot, sweat to cool off)

Question 8

what are transport proteins?

Answer 8

structures inside the membrane that allow large or charged particles to cross (selecitvely)

Question 9

what is diffusion?

Answer 9

movement of particles from a high concentration area to a low concentration area

Question 10

what is dynamic equilibrium?

Answer 10

continuos movement of partices without any change in concentration

Question 11

what is exocytosis?

Answer 11

release of waste or products from inside the cell

Question 12

what is osmosis?

Answer 12

diffusion but for water

Question 13

what is active transport?

Answer 13

movement of molecules across a cell membrane using energy

Question 14

define (iso, hypo, hyper)tonic

Answer 14

iso- same concentration of dissolved solute on either side of the membrane
hypo- lower outside than inside
hyper- higher outside than inside

Question 15

what structure is responsible for maintaining homeostasis?

Answer 15

cell membrane

Question 16

what is the cell membrane mainly made from?

Answer 16

phospholipid bilayer

Question 17

how long does diffusion keep going?

Answer 17

until equilibirum is reached

Question 18

if a cell is placed in salt water, water will:

Answer 18

leave the cell by osmosis

Question 19

what state are a plants roots in compared to soil?

Answer 19

hypotonic

Question 20

how does a cell move particles into an area of greater concentration (against the gradient)?

Answer 20

using active transport

Question 21

what are endo and exocytosis?

Answer 21

endo = in, exo = out

forms of active transport also called bulk transport or vesicular transport where the cell can take in or expel large objects.

endo: engulf the object
exo: vesicle wraps around object and carries it out