BIO MCAS

Hypothesis

An educated guess as to what you think will happen in your experiment.

Independent Variable

What you are changing in an experiment.

Dependent Variable

What you are observing in an experiment.

Control Group

The group that does not receive treatment in an experiment is the control group. It is the group that will be used for comparison.

Experimental Groups

The groups in the experiment that received the treatment.

Constants

Everything else in the experiment that remains the same.

Viruses

Not alive because they aren’t able to reproduce on their own. They need a host cell (the infected person) in order to reproduce.

Prokaryotic Cell

Bacteria is an Example. Simple cell - always unicellular - DNA is free floating - no Nucleus - Ribosomes - Cell membrane - cytoplasm - No membrane bound organelles

Eukaryotic Cell

Examples are Plants, animals, fungus, protist. More complex cell - unicellular or multicellular - DNA inside Nucleus - Ribosomes - Cell membrane - Cytoplasm - Has membrane bound organelles

Nucleotide (building block/monomers) of Nucleic Acids/DNA).

Made up of:

Deoxyribose sugar ⬠

Phosphate ⚫

nitrogen bases▭

Nitrogen Bases

Adenine - Thymine (base pair) Cytosine - Guanine (Base pair)

Complementary base pairing

ATTTCCGCT

TAAAGGCCA

Interphase

Made up of three stages:

-G1 (growth of cell)

-S (duplication of DNA) (cells need DNA to work properly as they code our genetic material)

-G2 (more growth)

Cells spend most of their time in Interphase

How does DNA duplicate during S phase?

DNA is split down the middle by DNA helicase. DNA polymerase helps attach complementary (A with T) base pairs to form  two new strands of DNA.

Mitosis

The process of making two identical cells (daughter cells) from one mother cell.

Cytokinesis

After mitosis when the mother cell (original cell) divides into two identical cells. These two cells are called daughter cells. The mother cells and daughter cells are all identical.

Why do cells go through Mitosis?

When we are growing we need more cells. Cells need to be replaced because they die off. Cells only last for a specific amount of time.

Allele

version of a gene, you have two alleles for each gene (ex. you receive one allele from your mom for eye color and one allele from your dad for eye color)

Genotype

The letters that code for a particular trait (ex. GG. Gg or gg)

Phenotype

what something looks like based off of genotype (ex. Brown eyes)

Heterozygous

two letters of the genotype that are different, usually one lowercase and one uppercase.(ex. Gg)

Homozygous

two letters of the genotype that are the same (ex. GG or gg)

Dominant

the trait that will show through when genotype is (GG or Gg for standard Dominant/Recessive traits)

Recessive

the trait that will only show through if there are two recessive alleles (ex. gg)

Incomplete Dominance

Neither allele is dominant. When an organism is heterozygous for a trait, it will show a third phenotype. The third phenotype is a blend of the other two. There is a dominant trait, a recessive trait and a trait that is somewhere in between.

Codominance

both phenotypes are expressed

Sex-linked traits

These happen on the 23rd chromosome which is the chromosome that determines gender. These happen more frequently in males.

Dihybrid Crosses

Crosses of more than one trait

DNA

Double strand - Contain deoxyribose sugar - Contains the nitrogen base Thymine

mRNA

Single strand - Contains ribose sugar - Contains the nitrogen base Uracil

Transcription

The process whereby a strand of DNA codes for the creation of an RNA strand. It is the first step in making a protein. Building block of a protein is an amino acid.

-happens in the nucleus of the cell

Translation

The process where the ribosomes read the mRNA. This is done in groups of three which is called a codon.

Immigration

people/animals moving into an area

Emmigration

people/animals moving out of an area

Carrying capacity

a species’ average population size in a particular area. Population size can be limited by:

Biotic factors - food supply, water supply, adequate shelter, mates, predators

Abiotic factors - natural disasters such as flood and fire, or disease 

The population would level off at this point with small dips and increases along the way.

Food Chains

Each level of a food chain is called a trophic level

Producers

the bottom of the food chain. They are plants, fruits and vegetables. The amount of producers will ultimately determine how large an ecosystem can be.

Primary consumer

eats the producer (usually a herbivore (only eats plants))

Secondary consumer

eats the primary consumer (usually a carnivore (only eats meat))

Tertiary consumers

eat the secondary consumer. (usually an omnivore that eats plants and animals)

Decomposers

clean up the dead material by processing it and returning the nutrients to the soil for the producers

Food Webs 

A more complex food chain. It shows various food chains put together.

Carbon Cycle

Plants remove carbon dioxide from the air through the process of photosynthesis and release oxygen into the environment.  Carbon enters the atmosphere from the burning of fossil fuels as well as humans exhaling. This cycling of carbon is called the carbon cycle. This constant exchange of carbon dioxide and oxygen helps to keep carbon level steady.

Nitrogen cycle

The nitrogen cycle describes how nitrogen moves between plants, animals, bacteria, the atmosphere (the air), and soil in the ground. Bacteria play a key role in moving nitrogen between the atmosphere and plants.

Predators

animals that eat other animals

Prey

the animals being eaten

Commensalism

a relationship between two organisms where one organism benefits and the other is unaffected.

Mutualism

a relationship between two organisms where both benefit.

Parasitism

one organism benefits and the other is harmed

Biodiversity

The variety of life in a particular ecosystem