Science Praxis 5005 (Life Science)

Living things

have physical entities and biological processes, such as homeostasis cell division, cellular respiration, and photosynthesis.

What are nonliving things classified as?

inanimate

Cell theory

(biology) the theory that cells form the fundamental structural and functional units of all living organisms

What are the three components that make up cell theory?

1. All living things are composed of cells

2. The cell is the smallest unit of life

3. All cells come from pre-existing cells.

What is the organization of life?

cell, tissue, organ, organ system, organism

Prokaryote

A unicellular organism that lacks a nucleus, mitochondria, or any other membrane-bound organelle.

What floats freely throughout the prokaryote cell?

DNA

What are the two domains of prokaryotes?

Bacteria and Archaea

Eukaryote

a multicellular organism that contains a nucleus, mitochondria, and membrane-bound organelles

Organelles

the structures within the cell membrane or cell wall

cellular membrane

fluid, the permeable outside covering of the cell. In a plant cell, this is a cell wall and it is rigid.

Nucleus

Command center of the cell. Controls of the rest of the cell.

Where does DNA live in eukaryotic cells?

the nucleus

Mitochondria

Powerhouse (energy source) of the cell

Cytoplasm

Water-like substance in the cell

What are Bacteria and Viruses?

prokaryotic cells and can only be seen under a microscope.

Bacteria

usually harmless

Virus

Causes diseases

What are animal and plant cells?

Eukaryotic

Animal Cell

does not have a cell wall or chloroplast and a small vacuole.

Plasma membrane

Cellular respiration

Plant Cell

contains a cell wall, chloroplast, and large vacuole

Photosynthesis

symbiotic relationship

close interaction between species in which one species lives in or on the other

cellular respiration

Animal Cells go through this

Taking in food in the form of carbohydrates, making energy in the form of ATP, and removing waste.

Photosynthesis

Plant cells make their own food through this process.

Using carbon dioxide, water, and sunlight, and turning them into carbohydrates.

sexual reproduction

involves two parents

Each parent contributes a gamete to the process of reproduction.

Occurs in plant and animal cells

What is a gamete?

sex cell

asexual reproduction

involves one parent

How do prokaryotes reproduce?

asexually through binary fission

While prokaryotes do not go through mitosis...

the cell does split into identical copies

binary fission

when a single parent cell doubles its DNA, then divides into two cells. Occurs in bacteria.

Budding

when a small growth on the surface of parent breaks off to continue growing into adulthood.

Occurs in yeast and some animals.

Fragmentation

when a piece of an organism breaks off, and those pieces develop into a new organism. This happens with starfish.

Parthenogenesis

when an embryo develops from an unfertilized cell.

Occurs in invertebrates as well as some fish, amphibians, and reptiles

Mitosis

a series of steps in creating an identical cell from another cell.

Cell Theory

All cells come from pre-existing cells

Interphase

NOT a part of mitosis

The cell prepares for division. It plumps up and replicates its DNA within its nucleus.

Prophase

The DNA tightly coils into chromosomes to make splitting efficient. The nuclear membrane dissolves. The microtubes or spindle fibers move to opposites sides of the cell.

Metaphase

The chromosomes (tightly coiled DNA) move to the middle of the cell. The spindle fibers attach to each chromosome.

Anaphase

The spindle fibers begin to pull apart the chromosomes, bringing them to opposites sides of the cell for efficient splitting.

Telophase

With the chromosomes at either side of the cell, the two new cells pinch off, forming two identical sister cells of the original cells.

Cytokinesis

when the cell separates into two cells during the final stage of mitosis.

Meiosis

Ensures that humans have the same number of chromosomes in each generation. Two-step process that reduces the chromosome number by half-from 46 to 23 to form sperm and egg cells.

Trisomy

extra chromosome (down syndrome)

DNA

the hereditary material in living organisms

Where is DNA located in eukaryotes?

nucleus and mitochondria

What does DNA contain?

a code using four nitrogen bases

What are the nitrogen bases

Adenine, Thymine, Guanine, Cytosine

What are the pairs of nitrogen bases?

Adenine (A) pairs with Thymine (T)

Guanine (G) pairs with Cytosine (C)

As pair with Ts

Cs pair with Gs

Amino Acids

organic compounds that from proteins.

How many different amino acids are there?

20

chains of amino acids make...

proteins

DNA Replication

the process of making a copy of DNA

What is necessary for the survival of an organism?

DNA replication

What is the process of DNA replication?

1. The DNA unzips

2. Free-flowing nucleotides (As, Ts, Gs, and Cs) bind to the unzipped portion of the DNA

3. Two identical DNA strands are the result

Gene

the basic physical and functional unit of heredity

What are genes made up of?

DNA

How many copies of each gene do you have?

2 copies

one inherited from each parent

Alleles

forms of the same gene with slight differences in their sequence of DNA bases.

Dominance

when the effect of one phenotype of one allele masks the contribution of a second allele.

the first allele is... and the second allele is...

dominant, recessive

Example of dominant and recessive

Brown eye color is dominant over blue eye color (recessive)

For a person to have blue eyes...

they must have both recessive alleles

Gregor Mendel

The father of genetics - Experimented with pea plants

What did Gregor Mendel show?

when a true-breeding yellow pea (YY) and a true-breeding green pea (yy) were crossbreed, their offspring always produced yellow seeds.

Metamorphosis

the process of transformation from an immature form to an adult form in two or more distinct stages. There are two types

Complete metamorphosis

the insect goes through four stages: egg, larva, pupa, and imago

What is an example of complete metamorphosis?

a caterpillar changes completely into something else: a butterfly

Incomplete metamorphosis

the insect hatches from an egg and then goes through several nymphal stages

What is an example of incomplete metamorphosis?

grasshoppers gradually get bigger, but they do not change into something else. Each stage of growth looks like a bigger version of the original stage

Evolution

a type of change that happens over thousands of years

What do organisms not do?

evolve

Adaptation

the distribution of traits in the population that is matched to and can change with environmental conditions.

Natural Selection

Developed by Charles Darwin and Alfred Russel Wallace. A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Mutations

changes in the DNA molecule caused by mistakes during cell division or exposure to environmental factors

What must all organisms be all to do?

grow, reproduce, and maintain stable internal conditions even when the world and environment around them change.

What is the behavior of individual organisms influenced by?

internal cues (hunger and internal temperature) and external cues (changes in the environment)

Homeostasis

The tendency to maintain a stable, relatively constant internal environment.

Cold-blooded

Animals that have a body temperature varying with that of the environment

What are some cold-blooded animals?

amphibians, reptiles, fish, and insects

Warm-blooded

Animals that maintain a constant body temperature, regardless of the temperature in the environment.

What are some types of warm-blooded animals?

mammals and birds

Vertebrates

animals that have a backbone

Invertebrates

Animals without backbones

Open Circulatory System

the blood is pumped into the body cavity and is not enclosed in blood vessel

What types of animals have an open circulatory system?

most invertebrates-insect, crustaceans, most mollusks

Closed Circulatory System

the blood is pumped by the heart and is enclosed in blood vessels

What types of animals have a closed circulatory system?

Most vertebrates-mammals, reptiles, fish, birds

Circulatory and Respiratory System

Responsible for the flow of blood; nutrients, oxygen and other gases, and hormones to and from cells.

What organs are a part of the circulatory and respiratory system?

heart (cardiovascular)

lungs (pulmonary)

arteries, veins, coronary and portal vessels (systemic)

Digestive and Excretory System

responsible taking in food and breaking it up into nutrients the body will use for fuel. It also removes the waste left over after the food is processed for nutrients.

What organs are a part of the digestive and excretory system?

gastrointestinal tract (stomach and intestines)

bladder

colon

kidneys (filter the blood)

Nervous, Endocrine, and Immune System

the master control system

What organs are a part of the nervous, endocrine, and immune system?

brain-hypothalamus, thalamus, and pituitary gland

spinal cord

neurons

hormones

classification system

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Species

a group of interbreeding organisms that do not ordinarily breed with members of other groups

Ex: Polar Bear

Populations

Comprises all the individuals of a given species in a specific area or region at a certain time. Can evolve over time because of genetic variation.

Ex: Includes all polar bears in the Artic Circle.

Communities

All the populations in a specific area or region at a certain time. There are many interactions among species (food webs)

Ex: polar bears, the penguins, the fish, and the plants make up this...

Ecosystems

The dynamic entities composed of the biological (living) community and the abiotic (nonliving) environment.

Ex: The Artic is made up of the water/ice, the animals, and the atmosphere in that area

Producers (plants)

produce their own food from sunlight, carbon dioxide, and water. The bottom of the food web/energy pyramid

Consumers

eat their food, categorized into four categories: