Biology Honors Midterm Exam 2023

What is Biology?

The study of life

What is the difference between an observation and an inference?

An observation is a description of an event using your senses. An inference is an educated guess based off of what you already know.

Why is a hypothesis useful?

They are used for everyday problem solving. They also help you to start the foundation of a scientific experiment.

Describe how a hypothesis should be written.

In the "If... Then...." form. Must be testable.

Hypotheses are derived from ________.

Inferences and observation

What are the basic steps of the scientific method?

Inquiry, hypothesis, designing controlled experiments, collecting and analyzing data, draw a conclusion, develop a theory.

What is the difference between independent and dependent variables?

Independent: the part of the experiment the scientist changes. Dependent: the varying outcome of the experiment; the data collected during the experiment.

What should happen at the conclusion of an experiment?

Developing a theory

What is the difference between scientific theory and fact?

Theory: a hypothesis that has been tested over and over again by many different scientists with similar results. Fact/Law: an observation that has been repeatedly confirmed with endless testing and consistent results, usually a mathematical formula is involved.

What are the characteristics of life?

Made of cells (one or many), can reproduce, are based on a universal genetic code (DNA), grow and develop, obtain and use materials and energy, respond to their environment, maintain homeostasis, and as a group change/evolve over time.

What are the metric units for length?

millimeters, centimeters, meters, kilometers

What are the metric units for mass?

grams and kilograms

What are the metric units for volume?

milliliter, liter

What is binomial nomenclature?

The process of assigning names to organisms, contains two parts.

What is included in an organism's scientific name?

genus and species

What are the 3 domains?

Bacteria, Archaea, Eukarya

What are the characteristics of the 3 domains?

Bacteria: common and current bacteria. Archea: ancient bacteria that live in extreme environments. Eukarya: organisms with complex cells (includes the 4 kingdoms).

Ecology

Scientific study of interactions among organisms and between organisms and their environment

Biotic

living

Abiotic

Non-living

Niche

An organism's particular role in an ecosystem, or how it makes its living.

Habitat

Place where an organism lives

The levels of organization, in order:

Species, population, community, ecosystem, biome, biosphere

Species

A group of similar organisms that can breed and produce fertile offspring.

population

A group of individuals that belong to the same species and live in the same area

community

All the different populations that live together in an area

ecosystem

A community of organisms and their abiotic environment

biome

group of ecosystems that have the same climate and dominant communities

biosphere

All of Earth that is inhabited by life.

What are the four characteristics that are important to study in population ecology?

geographic range, density and distribution, growth rate, and age structure.

What are the three types of dispersion patterns?

clumped, uniform, random

What are four ways a population size can change?

Emigration, immigration, birth, and death

Explain exponential growth (graph and examples)

The rate of population growth increases under ideal conditions.

explain logistical growth (graph and examples)

idealized population growth that is eventually slowed down by limiting factors.

What is carrying capacity?

the maximum population size that a particular environment can sustain

What do age structure graphs show us about a population?

They show how many people of each gender in each age group there are in a population

How has human population size changed over time?

exponential growth

What factors have influenced human population change?

industrial revolution, modern medicine, abundance of resources

What is the difference between density-dependent and density-independent limiting factors?

Density-dependent: limiting factors whose intensity is related to population density. Density-independent: limiting factors whose intensity is unrelated to population density.

List the six interactions that are common in a community and who benefits from each one?

Interspecific competition (-/-), Mutualism (+/+), Herbivory (+/-), Parasitism (+/-), Commensalism (+/0), and Predation (+/-).

What does a typical predator-prey relationship look like in a normal ecosystem?

One organism hunts, kills, and eats another organism

What are the seven feeding relationships in an ecosystem? Give examples of each.

Producers (make their own food through photosynthesis), primary consumers (herbivores), secondary consumers (carnivores/omnivores), tertiary consumers (carnivores), detritivores (eat dead organic matter ex. dirt), scavengers (eat animals that are already dead), decomposers (break down dead matter [bacteria]).

What is a trophic level?

Each step in a food chain or food web

What do energy pyramids show us?

Shows us the relative amount of energy available at each trophic level.

What do biomass pyramids show us?

represents the amount of living organic matter at each trophic level

What do numbers pyramids show us?

represents the relative number of individual organisms at each trophic level

What is a common theme amongst all pyramids?

largest at the bottom, smallest at the top

What is a keystone species? Give an example.

A species whose impact on the community is much larger than its abundance would indicate (ex. wolves, sea otters, parrotfish, beavers, sea stars, etc.)

What is trophic cascade? Give an example.

A trophic cascade is a chain-reaction within food webs that results from changing population densities at higher trophic levels, shifting the dominance and impact of consumers at lower levels.

What is Niche Partitioning?

A mechanism that facilitates coexistence

Atom

The smallest basic unit of matter

Element

A particular kind of atom; cannot be broken down into a simpler substance

What makes up 96% of the human body?

hydrogen, carbon, oxygen, nitrogen

How are molecules different from elements?

Molecule: substances composed of two or more atoms of element.

Element: one particular type of atom and cannot be broken down into simpler substances

What is biochemistry?

Chemistry of living things

Explain organic

natural, containing carbon

Which biomolecules are CHO?

carbohydrates and lipids

Which biomolecule is CHON?

proteins

Which biomolecule is CHONP?

nucleic acids

What is unique about the bonding of carbon?

it allows it to bond up to four different atoms

What is the monomer and polymer of carbohydrates?

monosaccharides and polysaccharides

What is the monomer and polymer of lipids?

Monomer: Fatty Acid & Glycerol.

Polymer: Triglyceride (human body fat)

What is the monomer and polymer of proteins?

Monomer: amino acids.

Polymer: polypeptides

What is the monomer and polymer of nucleic acids?

Monomer: Nucleotides.

Polymer: DNA and RNA

What are the differences between monosaccharides, disaccharides, and polysaccharides?

Monosaccharides: 1 - Fructose and Glucose. Disaccharides: 2 - Sucrose. Polysaccharides: Many - Cellulose (starch).

Explain dehydration synthesis

The removal of water to bond molecules

What is removed from dehydration synthesis?

water (H20)

Explain hydrolysis

the addition of water to break apart 2+ bonded molecules

What is added during hydrolysis?

water (H20)

What are examples of lipids?

fats, oils, waxes

Where are phospholipids found?

cell membrane

What do proteins do?

eyesight, muscle movement, digestion, pretty much everything

How many amino acids exist?

20

How many amino acids do humans naturally have?

12

Where do we obtain amino acids?

eating food

List the four parts of an amino acid:

hydrogen atom, an amino group, a carboxyl group, a differing side or R group

What are the two types of nucleic acids?

DNA and RNA

Explain the structure of a nucleotide.

sugar, phosphate group, nitrogenous base

Anton van Leeuwenhoek

Invented the microscope and discovered bacteria

Robert Hooke

first to observe "small chambers" in cork and call them cells.

Matthias Schleiden

concluded that all plants are made of cells

Theodor Schwann

concluded that all animals are made of cells

Robert Brown

discovered the nucleus

List the three parts of cell theory:

1. Cells are the basic units of structure and function in living things.

2. All cells come from other cells.

3. All organisms are made of one or more cells.

What is the difference between prokaryotic and eukaryotic cells?

Pro (no) Eu (Do) have a nucleus and membrane-bound organelles.

What are the special types of proteins in the cell membrane?

Peripheral and integral proteins

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water through a selectively permeable membrane

Three types of osmosis:

hypertonic(above), hypotonic(below), isotonic(equilibrium)

Passive transport

the movement of substances across a cell membrane without the use of energy by the cell

Facilitated diffusion

Movement of specific molecules across cell membranes through protein channels (passive)

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

What is the difference between endocytosis and exocytosis?

Endo - things come in the cell. Exo - things leave the cell

Vacuole

Cell organelle that stores materials such as water or waste. Very large in plant cells.

Cilium (cilia)

Short, hairlike projections that help move objects. Found in respiratory and digestive cells.

Centriole

One pair per cell, a structure in an animal cell that helps to organize cell division. Is typically close to the nucleus.

Lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell (hydrolysis).

Cell/Plasma Membrane

Phospholipid bilayer with embedded proteins. Protects the cell, controls what enters and exits the cell.

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Mitochondrion

The powerhouse of the cell. Makes energy for the cell to use. Lots in muscle cells.