multicellular organisms Flashcards
use of mitosis
produces new cells for growth and repair of damaged cells, maintains chromosome complement.
a cell divides every twenty minutes how many cells produced after one hour?
8
what is produced at the end of mitosis
2 identical daughter cells
what controls mitosis
nucleus
the central nervous system contains
brain and spinal cord
cerebrum controls
movement and conscious thoughts
cerebellum controls
balance and posture
medulla controls
heart rate and breathing
how are messages carried around the body
hormones + nerves
what are the 3 neurons
sensory- inter - motor
what is function of sensory neuron
pass information from sense organs (ears,nose,eyes,hands) to the CNS
what is the function of the motor neuron
enable a response to occur at an effector
what is the function of an inter neuron
processes information from senses that require a response
flow of information order
stimuli-receptor-sensory-motot-effector-response
what travels along the sensory neuron
electrical impulses
how are responses carried
eletrical impulses
how do messages travel from one neuron to another
synapse
hormones are released from
endocrine gland
hormones are
chemicals traveling in the blood acting slower
what hormone causes an increase in blood pressure
insulin
what hormone causes a decrease in blood pressure
glucagon
what organ produces insulin
pancreas
what is the target tissue for insulin and glucagon
liver
glucose is
a small soluble carbohydrate
what are hormones
chemical messengers
what is fertilization
fusion of nuclei of two haploid gametes to produce a diploid zygote which divides to form an embryo
describe pollen
male gamete in plants, found in the anthers.
describe ovules
female gametes in plants, found in the ovary.
events of pollination
transfer of pollen from the anther to the stigma. often carried out by bees.
what is variation
genetic differences between individuals of the same species.
two types of variation are
discrete, continous
example of discrete variation
eye colour, blood type ear lobes
example of continuous variation
human hand span, shell diameter in limpets
definition of an allele
different forms of a gene
definition of phenotype
physical appearance based on the genotypes
definition of genotype
an indivuduals allels for a particular characteristiv
what organs do plants have
leaves , stem , roots
xylem structure
one direction , dead cells, ligmified, water only
phloem structure
both direction , living cells , sieve tubes, glucose only
whats transpiration
process of water moving through a plant and its evaporation through the stomata in the leaves.
what can be used to measure transpiration
potometer
what affects transpiration positively
wind speed, temperature, surface area
what affects transpiration negatively
humidity
how can the cytoplasm be continuous
sieve plates
what job does the blood do
transport nutrients ,oxygen and carbon dioxide around the body
what is blood made of
red blood cells, white blood cells, plasma
name 2 white blood cells
phagocytes lymphocytes
atrierys carry blood ________ from the heart
away
veins carry blood _____ to the heart
back
describe veins
large central channel, thin muscular walls , high pressure
describe arteries
small central channels , thick muscular walls, low pressure
describe capillarys
allow efficent exchange of materials, large surface area.
