Chapter 3 Flashcards
Vesicles that exit the Golgi complex after cell products have been processed
- May remain in the cell as lysosomes
- May fuse with the plasma membrane, releasing their contents by exocytosis
- Move along the cytoskeleton to their destination
Cell products are ___ as they move through the Golgi complex.
chemically modified
The type of RNA molecule that translates the nucleotide sequence of a gene to the amino acid sequence of a protein is ___ RNA.
transfer
Methylation of cytosine bases and post-transnational modification of his-tone proteins are examples of processes associated with
- gene silencing
- epigenetic inheritance
Match to description of ribosome:
A
B
C
A= small (30S) subunit B= large(50S) subunit C= future location of transfer RNA molecules
A technique that examine the consequences of the absence of a functional gene involves developing specific strains of mice, called ___ mice, in which the gene of interest has been inactivated.
knock out
The diagonally arranged protein fibers in the figure, consisting of _____, form the cells skeleton or cytoskeleton.
- Micro-tubules
- Micro-filaments
The structure that forms in the cytoplasm as mRNA attaches to and is translated by many ribosomes is called a _____
polysome
G1:
S:
G2:
G1: Normal physiological processes occur, including gene expression from euchromatin
S: replication of euchromatin DNA
G2: hetero-chromatin formation begins
Before S of inter-phase, the genetic material in a cell exists as individual structures called ___; after G2 of inter-phase, the replicated genetic material consists of two structures called ____
Chromosomes … chromatids
The composition of the plasma or cell membrane is best described as a bi-layer
of phospholipids in which proteins are embedded
The manufacturing pairs of chromosomes in a diploid cell are called ______ chromosomes.
homologous
The nucleus of a cell
- is the site of transcription
- contains one or more nucleoli
When referring to the ____ of a species, the term is understood to include all of the genes in individuals
genome
Secretion of cellular products from membrane-enclosed vesicles to the extracellular environment occurs by means of ____
exocytosis
Describing the plasma membrane as a “fluid mosaic” is a reflection of
- The role of phospoholipids as the fluid background in which proteins are embedded
- The constant lateral movement of both proteins and phospholipids
- The unequal distributions of proteins as a mosaic pattern in the membrane
In the figure, panel ___ illustrates the smooth endoplasmic reticulum and panel ____ illustrates the rough endoplasmic reticulum
2, 1
DNA replication is said to be semiconservative because
One of each of the daughter strands is newly synthesized, and the other is from the original DNA molecule
The presence of microvilli on the apical surface of cells lining the intestine and kidney tubules permits rapid
- Absorption of the nutrient molecules
- Diffusion of water into the cells
In the figure, the letter ____ indicates the nucleus
A
The sequence of ___ in mRNA determines the sequence of amino acids in a polypeptide chain
codons
Match the phases of mitosis to the events that occur in each
Prophase:
Metaphase:
Anaphase:
Telophase:
P: Nucleolus no longer visible, nuclear envelope disappearing, sister chromatids visible, centrioles begin migration, spindle fibers forming
M: nuclear envelope disappears, chomatids single fibers from each centriole attach to centromeres of chromatids
A: centromeres separate sister chromatids separate and chromosomes are pulled to opposite poles of cell
T: chromosomes decondense, nuclear envelope and nucleolus become visible, cleavage furrow begins to form
Nearly every cell in the body possesses a single, non-motile ___ that may provide sensory function for a cell
primary cillium
When an RNA molecule complementary to a DNA molecule has been synthesized,
- Gene transcription has occurred
- DNA-directed RNA synthesis has occurred
- RNA polymerase has engaged with a promoter sequence
Genes that may initiate development of cancer, called _____, are altered forms of normal genes, called _____, that code for proteins regulating the cell cycle
oncogenes, proto-oncogenes
Identify the characteristics of agranular (smooth) endoplasmic reticulum
- stores calcium striated muscle cells
- abundant in cells that metabolize steroid hormones
The final product of genetic translation is a(n)
polypeptide
Nuclear pore complexes permit small molecules to pass through by ____; movement of large molecules (RNA, protein) requires ____.
diffusion….. active transport
All animal cells contain a non-membranous mass in the cytoplasm, called a ______, consisting of two rod like centrioles
centrosome
Carbohydrates can attach to plasma membrane ____ and ______
phospholipids, protiens
Evidence of death of a cell within a tissue or organ by necrosis include:
- the cell bursts
- the cell swells
- the plasma membrane of the cell ruptures
The term________ describes growth that occurs as a result of an increase in the size of the individual
hypertrophy
A normal stage of _____, or programmed cell death, involves the release of lysosomal enzyme into the cytoplasm, destroying the cell
apoptosis
The genes in mitochondrial DNA
- are contained in a single circular chromosome
- are inherited from the mother
Identify the characterisics of granular (rought) endoplasmic reticulum
- abundant in secretory cells
- ribosomes are on surface
Nucleoli
are composed of DNA
All fluid, organelles and inclusions between the nuclear membrane and the plasma membrane has been termed
cytoplasm
Cellular death within tissues and organs caused by or involving disease is called
necrosis
By the process called, which literally means “self-eating”, worn out organelles are destroyed and then replaced
autophagy
The mitochondia in human cells
- may have originated from bacteria-like organisms
- have their own DNA
- can self-replicate
Acetylation of condensed chromatin produces a more open structure that can be activated by ____ factors, resulting in the synthesis of messenger RNA(mRNA)
transcription
During DNA replication, which occurs before mitosis and meiosis, _____link DNA bases together to form a new strand of DNA
DNA polymerases
Neutrophils and macrophages extend cytoplasm into the extracellular matrix, forming ____
pseudopods
A ___ codon must be present in an mRNA molecule to begin translation, and a ___ codon must be present to terminate translation
start, stop
Chromatin
- is a term that refers to the composition of chromosomes
- is composed of DNA and protein
Most growth in the human body is the result of
hyperplasia
When a gene is transcribed
- an RNA molecule is synthesized
- RNA polymerase has made one molecule complementary to one strand of DNA
DNA at the end chromosomes, called ____ , is not fully copied by DNA polymerase and is progressively lost with each mitotic cycle, which may correlate with the aging process.
telomeres
Substances moved by the beating of motile cillia include
- an oocyte in the uterine tube
- mucus in the trachea(respitory tract)
A membrane-bound sac containing only digestive enzymes in an environment with a lower pH
primary lysosome
The components of a plasma membrane that provide structural support, transport substances through the membrane, and participate in chemical reactions at the cell surface are
protiens
Regulatory proteins called ____ promote different phases of the cell cycle
cyclins
Transmission of DNA sequences in chromosomes is called _____ inheritance; transmission of the structural modification that alter the availability of DNA sequences for transcription is called ____ inheritance
genetic, epigenetic
Each tRNA molecule has a three-nucleotide sequence complementary to a specific codon in an mRNA molecule called a
anticodon
Exchanges of parts of homologous chromosomes that occur in prophase 1 of the first meiotic division creates genetic ____
recombination
Ribosomes linked by mRNA form a structure called a _____
- polysome
- polyribosome
Each nuclear pore complex is formed by interconnected rings and columns of ____ and has a central opening called ____
protein…. nuclear pore
The sequence of a tRNA anticodon
- will determine the amino acid that will be attached to the tRNA molecule
- will base-pair with the complementary mRNA codon
- will be the same as the DNA triplet unless the DNA sequence contained thymine
