BIOB 110CS Exam 4 QUESTIONS

Louis Pasteur

Culture did not become contaminated with bacteria when held in a flask with a long, curved neck.

So Lysenko was a political campaign led by the Soviet biologist Tromfim Lysenko. He was against genetics and science-based agriculture. He rejected natural selection in favor of Lamarckism. Lamarckism is the idea that an organism can pass phenotypical characteristics that the parent acquired through its life. Almost like epigenetics. Lamarckism is a contrast to Darwin's evolution theory.

Individuals of a species are not identical; traits are passed from generation to generation; more offspring are born than can survive; and only the survivors of the competition for resources will reproduce.

Gregor Mendel

Repetition of experiments

Law of Segregation (1:3:1)

Two daughter cells divide again without DNA duplication, so the end result is the creation of haploid gametes with half of the DNA complement of the original cell

2N

1N

Assortment of alleles

Mendel's First Law

Stress conditions, pathogen attack or other environments changes can affect gene expression

The soil bacterium causes crown gall disease by transferring genes for auxin and cytokinin synthesis from its Ti plasmid into the host plant. Researchers remove these genes and replace them with desired genes

Modified starch, oil content/composition, flower color, improved shelf life, and nutritional content

Dependence on chemical and synthetic inputs, unknown and unpredictable damage to human health, foods are unlabeled, gene flow

USDA, EPA, FDA

To characterize risks, the assessor predicts the probability, nature, and magnitude of the adverse effects that might occur

Toxicity x Exposure

Because the pollen from Bt crops landed on Milkweed and affected Monarch Butterflies

Using plants to soak up bad things in the soil

Genetically editing plants/animals so that they can be used as pharmaceuticals

Depends on:
Does the GM crop cross with a weed species?
If crossing is successful and hybrid seeds are formed, do they persist in the environment?
If the transgenic trait is expressed in the hybrid, does it confer a fitness advantage in the plant's natural habitat?

More likely because of species similarity

If the transgenic trait is expressed i n the hybrid, does it confer a fitness advantage

No

Possibly

Increased encouragement to survive, resistant pests more chance to breed

Inorganic minerals, organic matter, microorganisms, air, water

Organic matter, Microorganisms

Stack of horizontal layers (horizons) that differ from each other by physical and chemical characteristics

Layers of soil that differ from one another

0 Horizon (0-2 inches deep)
-"soil building process," rich in humus
A Horizon (2-10 inches deep)
-highest biological activity, highest concentration of organic matter
B Horizon (10-60 inches)
-zone of accumulation
C Horizon (below 60 inches)
-parent material

Gravel

Clay

Because they have been recrystallized, they act as negatively-charged anions and bind positively-charged molecules (cations) in the soil. Nutrients like ammonium, calcium, magnesium, iron, and potassium are bound to clay because of their positives charges

Negative

Water infiltration rates
Water-holding capacity
Nutrient content

It's dictated by the number and size of soil pores which is in turn controlled by soil particle size

Capillary action is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity.

Nitrogen, Phosphorus, Potassium

Nitrogen- growth, protein content, organic decomposition
Phosphorus- early root formation and growth, induces blooming and seed set
Potassium- disease resistance, winter hardiness

N- yellow, grow slow
P- dark green, purple leaf veins
K- wilting, general stunting, and chlorosis

No-till/Minimum-till, Contour farming, Buffer strips

Fertilizer runoff enters waterways and accumulates in the Gulf

Precision farming

The result of overly efficient summer fallow that allows extra water to accumulate and percolate downslope through the soil profile, accumulating salts as it travels. When this underground water reaches a barrier or bedrock, it accumulates at the surface and evaporates, but leaves the salt deposits behind.

If the recharge area can be identified then deep-rooted crops like alfalfa that use large amounts of water can be planted there to dry up the seep water source. Salt resistant plants can also be planted on the saline seeps.