Biologypre

7. produces ribosomal nucleic acid (RNA)

7 nucleolus

shipping and packaging center

Golgi apparatus

Which scientist discovered cells by observing cork with a homemade microscope?

Robert Hooke

mutation

a change in the genetic information code

(DNA) Deoxyribonucleicacid

a giant molecule consisting of the sugar deoxyribose, phosphates, and nitrogen bases

DNA (deoxyribonucleic acid)

a giant molecule consisting of the sugar deoxyribose, phosphates, and nitrogen bases; contains coded genetic information

RNA (ribonucleic acid)

a nucleic acid similar to DNA that uses ribose for the sugar and the nitrogen base uracil in place of thymine

gene

a segment of DNA that contains the information for making protein and, therefore, allows the nucleus to run the cell's activities and carry hereditary traits

A gene

a segment of DNA that contains the information for making proteins and allows the nucleus to run the cells activities and carry hereditary traits

Moving substances from a lower concentration to a higher concentration requires _____.

active transport

The science of genetics

all the traits of successive generations are inherited directly from their ancestors. In this lesson, you'll learn more about the "software" of cells—DNA—as well as the functions and structure of ribonucleic acid (RNA). Both DNA and RNA are fundamental to genetics and heredity.

The idea that the basic unit of life is the cell is called the _____.

cell theory

1. semipermeable; allows certain substances to pass through

cell wall

Which of the following are not characteristics of the plasma membrane?

cellulose

Which of the following are not characteristics of the cell wall?

cellulose and chitin

translation

converting the genetic code into the language of proteins

6. fibrous material giving support to the plant

cytoplasm

An electron microscope would be used if _____.

details of cell structures needed to be distinguished

In order for life to survive, bodies or cells must adjust to environmental conditions. This is called _____.

homeostasis

If an animal cell shrinks, it was probably placed in a _____.

hypotonic solution

A solution should be _____ in order to prevent water gain or water loss in a cell.

isotonic

enzyme producer for digestion

lysosomes

powerhouse of the cell

mitochondrion

Osmosis is a diffusion process that moves _____ through the membrane from higher to lower concentration.

molecules

2. controls activities of the cell

nucleus

5. functional plant or animal

organism

DNA is made of two long chains

paired nucleotides

4. thick fluid between plasma membrane and nucleus

plasma membrane

The _____ passively diffuses oxygen and carbon dioxide in and out of the cell.

plasma membrane

food and pigment storage

plastids

protein producers

ribosomes

chromosome

rod-shaped structure that contains DNA and is located in the nucleus

A membrane that allows only some materials to move in and out of the cell is _____.

semipermeable

DNA molecule

the DNA molecule has the consistent backbone of phosphate-sugar-phosphate-sugar-phosphate-sugar and so on. The portions of the molecule that vary are the bases and the sequence of bases present. The sequence of bases carries the coded message for the hereditary trait.

The organismal theory teaches that _____.

the basic unit of life is the organism

nucleotide

the combination of phosphate, sugar, and nitrogen bases in DNA or RNA; can combine to code a specific amino acid

replication

the separation of DNA's two polynucleotide chains, each of which then acts as a template for a new chain

transcription

the transfer of genetic code from DNA to an intermediary RNA molecule

endoplasmic reticulum

transportation highway of the cell

3. storage structure

vacuole

nucleotide

made of a nitrogenous base, sugar, and phosphate. The DNA structure looks like a twisted ladder, with the sides or railings of the ladder made up of repeating units of sugar (deoxyribose) and phosphate. The steps or rungs of the ladder are made up of paired nitrogenous bases. There are four different nitrogenous bases—adenine (A), cytosine (C), guanine (G), and thymine (T). Hydrogen bonds between the paired bases hold the two chains together. Adenine always pairs with thymine and cytosine always pairs with guanine. If one side of a DNA chain is GATACCA, then the other side must be CTATGGT. Together, the two nucleotide chains form a double helix structure (twisted ladder). In prokaryotes, DNA is coiled within the cytoplasm. In eukaryotes, DNA remains are surrounded by a nuclear membrane.

The nucleus of a cell is the control center

It contains the instructions for reproduction, heredity, and perhaps all the cell functions. A cell is somewhat analogous to a computer. And deoxyribonucleic acid (DNA) is the software containing all the operational programs.

The _____ microscope uses multiple glass lenses to help distinguish details of thickness.

electron

A light or optical microscope most commonly used is called a(n) _____.

electron microscope