Biology unit 2 test

The main function of a mRNA molecule is to?

Carry DNA's genetic message for translation

After DNA replication, a eukaryotic chromosome_______

Consists of 2 sister chromatids, has characteristic X shape, is constricted at the centromere

DNA replication requires ____

DNA polymerase, nucleotides, and primers

Variation in ___ is the basis of variation in traits.

DNA sequence

The phase 5 to 3 refers to the ____

Directionality of DNA synthesis

Most codons specify a(n) _____.

amino acid

Enzymes contained in _____ break down worn-out organelles, bacteria, and other particles.

lysosomes

Anticodons pair with

mRNA codons

Solutes tend to diffuse from a region where they are __ concentrated to another where they are ___ concentrated

more, less

What controls the passage of molecules into and out of the nucleus?

nuclear pores, which consist of membrane proteins

Where does transcription occur?

nucleus

Every cell is descended from another cell. This idea is part of ____.

cell theory

All mutations _____

change in DNA sequence

The surface-to-volume ratio

constrains cell size and is part of cell theory

Where does translation occur?

cytoplasm

Despite the diversity of cell type and function, all cells have these three things in common:

cytoplasm, DNA, and a plasma membrane

All antioxidants ______

prevent other molecules from being oxidized

A binding site for RNA polymerase is called a _____.

promoter

_____ are always changed by participating in a reaction

reactants

An RNA molecule is typically ___; A DNA molecule is typically ___

single stranded, double stranded

Up to ___ amino acids can be encoded by an mRNA that consists of 45 nucleotides plus a stop codon

15

What are the base pairing rules for DNA?

A=T and C=G

Energy that drives DNA synthesis comes from _______

ATP and DNA nucleotides

___ connect the cytoplasm of plant cells

Adhesion protein

A metabolic pathway may _____

Build or break down molecules, include electron transfer chain, generate heat

____ can change from one form to another

Energy

Only _____ cells have mitochondria

Eukaryotic

Energy that drives translation is provided mainly by_____

GTP

_______ is not a nucleotide base in DNA?

Glutamine

One species' DNA differs from others in its

Nucleotides, DNA sequence, sugar-phosphate backbone

Cell membranes consist mainly of ____ and ____

Phospholipids; protein

Correct order according to pathway of secreted proteins...

Plasma membrane, endoplasmic reticulum, Golgi bodies, post-Golgi vesicles

Most of a membrane's diverse functions are carried out by ____.

Proteins

Energy that drives transcription is provided mainly by ___

RNA nucleotides

A chromosome contains many different gene regions that are transcribed into different

RNAs

_____ is an example of reproductive cloning

SCNT and artificial embryo splitting

_____ is life's primary source of energy

Sunlight

Human body cells are diploid, which means _____.

They have two sets of chromosomes

A transport protein requires ATP to pump sodium ions across a membrane, this is a case of _____

active transport

If we liken a chemical reaction to an energy hill, then activation energy is like

a bump at the top of the hill

Entropy ____

a measure of disorder, always increases

The main function of the endomembrane system is ____.

building and modifying proteins and lipids

Immerse a human blood cell in a hypotonic solution, and water ______

diffuses into the cell

If we liken a chemical reaction to an energy hill, then a(n) _____ reaction is an uphill run

endergonic

Vesicles form during ______

endocytosis and phagocytosis

Unlike eukaryotic cells, prokaryotic cells

have no nucleus

Eukaryotic chromosomes, DNA wraps around?

histone proteins

In a lipid bilayer, _______ of all the lipid molecules are sandwiched between all the _______.

hydrophobic tails and hydrophilic heads

_____ are removed from new mRNAs

introns

______ cannot easily diffuse across a lipid bilayer

ions

Chromosome number ______

is an identifiable feature of a species

The main function of DNA molecule is to _____

store heritable information

Name one environmental factor that typically influences enzyme function.

temperature, pH, salt, pressure

When DNA replication begins,

the two DNA strands unwind from each other

RNAs form by _____; proteins form by _____.

transcription and translation