Transcript Genetics - Nutley Schools

Chapters 5, 18, 19, 22
Chapter 5
What is Genetics?
• Heredity: passing of traits from parents to
offspring
• Alleles: different forms a gene may have for a
trait
• Genetics: the study of how traits are inherited
through the actions of alleles
• Purebred- organism that always produces the
same traits in its offspring
The Father of Genetics
Gregor Mendel (Austrian Monk born in 1822)
Experimented with garden peas
– Quick germination
– Quick growth
– Easily observable traits
Mendel’s Experiments
• Mendel cross-pollinated purebred tall plants
with purebred short plants
– He pollinated the plants himself!
– Results: tall plants crossed with short plants
produced tall plants
• it seemed as though the short trait had
“disappeared”
Dominant & Recessive Factors
• Mendel called the tall plants “dominant”
• The tall “covered up” the short
• Dominant – tall
• He called the form that disappeared
"recessive”
• Recessive- short
What happened to the recessive (short) form?
Mendel’s Experiments
• Next, Mendel allowed the tall plants to selfpollinate
• Then, he collected the seeds from these tall
plants & planted them
• RESULT: for every 3 plants tall, there was 1
short plant (3:1 ratio)
– He saw this 3:1 ratio often enough to know
that the probability was great
– He would get the same outcome each time
Using A Punnett Square
Punnett Square: used to predict results
Dominant Allele = Capital Letter (G)
Recessive Allele = Lower Case (g)
Using a Punnett Square (con’t)
• Homozygous- organism with two alleles that
are identical for a trait (BB) (bb)
• Heterozygous- organism with two alleles that
are different for a trait (Bb)
Using A Punnett Square (con’t)
• Genotype- genetic makeup
• Phenotype- physical expression of the trait
Punnett Square Practice
Human Genetics
Investigating Inherited Traits Lab!
Chapter 18
Life & The Environment
Living & Nonliving Environment
• Biosphere- part of the earth that supports
living organisms
• Abiotic Factors- nonliving physical features of
the environment (air, water, soil, light, temp.)
• Biotic Factors- all of the living organisms in the
environment (plants, animals, etc.)
Characteristics of Populations
• Population Density: size of a population
occupying an area of a specific size
• Limiting Factor: any biotic or abiotic factor that
restricts the number of individuals of a
population
• Carrying Capacity: largest number of individuals
an environment can support & maintain for a
period of time
• Biotic Potential: number of individual each
female of a population can produce under the
best possible conditions
Predator-Prey Relationships
• Predation: feeding of one organism on another
Symbiosis- any close relationship
between 2 or more different species
(can be positive, negative, or neither)
Symbiotic Relationship
Description
Commensalism
One partner benefits, the other is neither
harmed nor helped in any way
Mutualism
Both species benefit
Parasitism
Benefits parasite and harms the host
Flow of Energy
• All energy is derived
from the sun
• Energy is transferred
from the sun through all
tropic levels
Only about 10% of the
energy available at each
level is transferred to
the next level.
Breakdown of the
Energy Pyramid
The level of the energy pyramid consists of:
– Producer (produces its own food)
– Primary Consumer (feeds on producers)
– Secondary Consumer (feeds on primary consumer)
– Tertiary Consumer (feeds on consumers)
Food Chain Terms
•
•
•
•
•
Producer: produces its own food
Herbivore: eats only plants
Carnivore: eats only meat
Omnivore: eats both plants & meat
Scavenger: feeds on dead remains of
plant/animal
• Decomposer: breaks down organisms &
returns nutrients to the soil
Food Chain- animals that have a
feeding relationship
Reminders:
1. food & energy are moving
from one organism to
another
2. Arrows are drawn in the
direction that energy flows
Label the food chain above using “food chain terms”
Food Web- linking together of food chains
Hydrologic (Water) Cycle
Evaporation from plants is called Transpiration
Nitrogen Cycle
Chapter 19
Ecosystems
How Ecosystems Change
Ecological Succession- process of gradual
change from one community of organisms to
another
Primary Succession
• Primary Succession- begins in a place that
does not have soil
– Lava flow, raised coral reef
Pioneer community- first community of
organisms in this new environment
– Hardy organisms that can survive drought,
extreme heat & cold, and other harsh conditions
Secondary Succession
• Secondary Succession- begins in a place that
already has soil
– Burned down forest, abandoned parking lot,
demolished building
Climax Community- has reached the final stages of ecological succession
- May take hundreds or even thousands of years
- Complex food webs
BIOMES
• Biome- large geographic areas with similar
climates & ecosystems
• Factors that Effect Biomes:
– Temperature
– Latitude
– Elevation
– Precipitation
TUNDRA
• Cold, dry, treeless region
• “Cold Desert”
w/ little rain
• Permafrost
(permanently frozen soil)
Popular Species: lichen, moss, grass, small shrubs,
muskoxen, reindeer, mosquitoes, birds, lemmings,
Arctic hares, caribou
TAIGA
• Cold region of cone-bearing
evergreens (pines, spruces, firs,
hemlocks, cedars)
• Shrubs & grasses (lichen, moss)
Popular Species: plants from
above, moose, black bears, lynx,
wolves
TEMPERATE DECIDUOUS FOREST
• You are here! (not at the mall)
• Trees lose leaves every autumn
– Beauty of Autumn
• Good soil = lots of vegetation
Popular Species: maple, oak,
beech, birch, sycamore trees,
deer, foxes, squirrels, mice,
snakes, huge number of birds &
insects
TROPICAL RAIN FOREST
• Found near the equator
• Abundant rainfall & high temperature &
humidity
• Unique plant & animal life
• Lush, dense forest
Popular Species: snakes, lizards, frogs, parrots,
toucans, cockatoos, humming birds,
ocelots, peccary, jaguars, orchids, ferns,
mosses, bromeliads
Layers of Vegetation
• Canopy- top of forest
(leafy branches of trees)
• Understory- shrub layer
• Forest Floor (dark &
moist)
GRASSLANDS
• Dominated by grass
• Little rainfall (more than desert or tundra)
• Grasslands are found on nearly every continent
Popular Species: kangaroos, wildebeests, zebras,
meadowlarks, prairie chickens & dogs, bison
wheat, oats, barley, rye, corn (harvested here)
DESERT
•
•
•
•
•
Driest biome on earth!
Less than 25 cm of rainfall yearly
Little plant life
Poor soil
Barren, Windblown
Popular Species: whitetail deer (largest population in
world), sagebrush, cacti, lizards, iguanas,
tarantulas, roadrunner, coyote
Adaptations of
Desert Plants & Animals
• Adaptation- any characteristic an organism has
that makes it better able to survive in its
surroundings… adaptations are INHERITED
PLANTS:
Cacti
Succulents
ANIMALS:
-Reduced spiny leaves
-Nocturnal
-Large, shallow roots
Or Fibrous Root System
-Burrow deep in ground
- Waxy Outer Coating
-Large ears (release body
heat)
- Rapid Germination
-Store water in bodies
Chapter 22
Nutrients & Digestion
WHAT do you eat?
• Breakfast:
• Lunch:
• Dinner:
• Snacks:
WHY do you eat?
• To obtain energy for your body to carry out
cell development, growth, & repair
NUTRIENTS
Nutrient- substances in foods that provide energy & materials for
cell development, growth, and repair
Carbohydrates Protein
Fats/Oils
Vitamins
Main source of Your body
Provide energy Needed to
energy for
uses proteins & help body
help your
your body
for growth
absorb vitamins body use
Amino Acidsother
building blocks of
nutrients
proteins
Minerals
Water
Regulate
chemical
reactions in
your body
Enables
chemical
reactions to
take place
Electrolytes
Foods that contain the same nutrients belong to a
food group
We have now moved toward the
“My Plate” model…
Antioxidants
Antioxidants- substances that prevent other
chemicals from reacting with oxygen
– fruits & vegetables are known to contain antioxidants
that lower the risk of getting various diseases
Enzymes- Nature’s Chemists
Enzyme (AKA: “CATALYST”)
substance that speeds a chemical reaction (without raising
the temperature)
*enzymes are not changed by reactions
Mechanical Digestion
Chemical Digestion
Food is chewed &
mixed in your mouth
and churned in your
stomach
Breaks down large
molecules of food into
smaller molecules that
can be absorbed by
cells
Small & Large
Intestine
Small Intestine
Villi- absorb nutrients into bloodstream
Large Intestine
Where it all ends!