Science STAAR Notebook
Biology - Category 4
Biological Processes and Systems
make
Which go together into
Groups of cells are called
That make the
inside you
And organs work inside
To make living
This is the way we’re organized
From simple to complex inside!
© Patrick Haney
STAAR Question
Which of the following levels of organization
lists the levels in order from the largest level
to the smallest level?
A cell, tissue, organ, organ system
B organ system, organ, tissue, cell
C organ, tissue, organ system, cell
D organ system, tissue, organ, cell
Levels of Organization Cont’d

After organisms:

Population – same organisms in an area


Community – different organisms in an area


Ex: different type of fish in a pond
Ecosystem – a community plus the non-living
factors (ex: rocks, soil, water)


Ex: people in a city
Ex: dessert or rainforest
Biosphere – many ecosystems together

Ex: earth
Homeostasis



Definition – animals and plants
maintaining a steady balance of water,
nutrients, and energy.
Examples: sweating when you get too
warm; plants closing their stomata to
regulate water lose
Sheldon‘s Homeostasis
Homeostasis

Feedback
mechanisms help to
maintain
homeostasis.


Stimulate – to make
more active
Inhibit/Suppress –
to make less active
STAAR Question
Changes in water pressure within guard cells cause
the cells to open or close the stoma. This response
helps the plant maintain homeostasis by –
A stabilizing the plant’s temperature through the
evaporation of water
B regulating the amount of water the plant loses
during transpiration
C allowing oxygen needed for photosynthesis to
enter the plant
D enabling the plant to release more carbon
dioxide at night for photosynthesis
Organ Systems




Digestive – delivers and absorbs useful nutrients;
produces chemicals to breakdown food
Circulatory – transports oxygen (O2) from the
respiratory systems and nutrients from the digestive
system to cells and carries wastes away from cells
Skeletal – protects your internal organs, gives your
body shape and support, and produces blood cells.
Muscular – is responsible for voluntary (jumping or
pointing) and involuntary (beating of your heart or
moving food through digestive tract) movement.
STAAR Question
The human digestive system is
approximately 900cm long. Food is
moved through the digestive tract
primarily by –
A bile produced by the pancreas
B the enzymes amylase and pepsin
C muscular contractions
D hydrochloric acid in the stomach
Organ Systems
Endocrine
– produces chemical messengers called hormones. These
help maintain homeostasis. Other hormones control development and
growth. Also found in plants.
Integumentary
– the “skin” - forms a protective barrier around the
body. Helps prevent water loss and controls body temperature. It also
gathers information about your surroundings.
Reproductive
– reproduces organisms; in males the reproductive
system produces sperm, and in females the reproductive system
produces eggs.
Respiratory
– moves oxygen (O2) into the body and carbon dioxide
(CO2) out of the body.
Organ Systems

Excretory – removes waste from the body


Nervous – detects changes and controls the way your
body responds to these changes



Ex: urine and feces
Ex: fear and stress increases breathing rate and heart rate
Immune – protects the body from infection.
Lymphatic – takes fluid from the spaces between cells
and returns it to the circulatory system. It also filters
bacteria and other microorganisms from this fluid.
STAAR Question
Which of the following correctly describes an interaction that occurs
between two body systems of a rabbit that helps the rabbit outrun a
pursuing coyote?
A The skeletal system releases additional calcium, and the circulatory
system retains more sodium in the blood to provide muscles with ions
for contraction.
B The digestive system increases the rate of digestion, and the
excretory system ceases to provide tissues with more nutrients.
C The respiratory systems increases the breathing rate, and the
circulatory system increases blood pressure to provide tissues with
more oxygen.
D The endocrine system releases hormones that prepare the immune
system to deal with possible injuries.
Plant Systems

Root System:

The root of a plant is responsible for
absorbing all of the water and nutrients that a
plant needs to grow.
Photo by Aaron Escobar
Plant Systems

Shoot System:

Stems –
gives structure to the
plant and supports the
leaves, flowers and
fruit.
 carries the water and
nutrients throughout
the plant through
vascular tissue. This
could be compared to
the circulatory system
of animals.

Plant Systems

Vascular System:
transport system


phloem
xylem
Xylem – tubes that
transports water
throughout plant
Phloem – tubes that
transports nutrients
throughout plan
Plant Systems
•
Reproductive System:
•
•
•
Some plants reproduce
using a specialized organ
known as a flower.
As pollinators collect nectar
from a plant to be used as
food, they also leave behind
a bit of pollen from the
previous plant.
This fertilizes the second
plant and allows the plants
to sexually reproduce.
Photos by Joaquim Alves Gaspar
STAAR Question
Copper is a micronutrient that can be found in the soil.
Copper is important for reproductive growth in plants and
plays an indirect role in chlorophyll production. Which
statement correctly describes the interaction that occurs
between the root and the shoot systems of plants to allow
reproduction to occur?
A Copper is produced in the roots when copper-containing
compounds are hydrolyzed.
B Copper that is absorbed by the roots is transported to
reproductive tissues by the shoot.
C The shoot system stores copper for later use by the roots
and the reproductive structures.
D The shoot system transports copper to the roots after it is
taken in through stomata in the leaves.
Plant Tropisms

Tropism – plant growth in response to a
stimulus (trigger) due to plant hormones.

Examples:
1. Phototropism – growth in response to light
 2. Geotropism – growth in response to gravity
 3. Hydrotropism – growth in response to water
 4 Thigmotropism – growth in response to touch

STAAR Question
Plant hormones serve as chemical
messengers between cells and tissues.
Auxin is a plant hormone that causes the
cells on the shady side of a plant shoot to
elongate. This response enabled by auxin is
known as –
A geotropism
B transpiration
C phototropism
D photosynthesis
Plant Adaptions

Examples:
– Annual rings of trees – thin in dry periods; thicker
when there is more rainfall.
– Plant leaves in an arid (dry) habitat are typically spiny
(for protection) and smaller.
– Because of a lack of water, the plant cuticle increases
in thickness. It is a structural response to the
environment.
– Plants absorb energy from the sun in their leaves. The
broader the leaf, the more sunlight absorbed.
– Seeds of a plant can be dispersed in different ways
depending on their structure. Seeds can be carried by
water, wind, or animals.
Enzymes
Enzymes function as CATALYSTS to speed up chemical reactions by
LOWERING THE ACTIVATION ENERGY of reactions.
 They may only catalyze one type of reaction and can be used over
and over again!!!!
 The substrate is the substance that the enzyme is working with; the
active site is the place on the enzyme where the substrate attaches
 Each enzyme has a definite 3D shape which
allows it to recognize and bind with its substrate
(like 2 puzzle pieces)
 Example: enzymes are used in the digestive
system to break food down into component
molecules for use by the body

What is needed to start a reaction?
Activation Energy- energy required to get a reaction
started.
STAAR Question
This diagram shows the biochemical pathway that
produces arginine in Neurospora, a mold. Neurospora is
easily grown on a simple jelly-like medium.
If Enzyme X were not functioning properly, what substance
would need to be added to the growth medium for this mold to
grow normally?
A Base substance
B Ornithine
C Enzyme Y
D Enzyme Z