Chapter 4, Genetic Control of Cell Function and Inheritance

Question 1

DNA Structure

Answer 1

Double helix. phosphate backbone.
CT- pyrimidine bases, 1 N ring
GA- purine bases, 2 N ring
composed of nucleotides, a phosphoric acid, 5 carbon sugar, and 1 of 4 nitrogenous bases

Question 2

Packaging of DNA

Answer 2

Autosomes and Sex chromosomes
genes are arranged linearly along each chromosome
small amts of RNA in a tightly coiled structure- chromatin
specfic group of proteins - histones

Question 3

Function of DNA

Answer 3

genetic coding. each cell contains all DNA, but they differentiate and decide what part they want to use

Question 4

DNA mutations

Answer 4

Insertion, deletion, duplication, inversion

Question 5

What types of mutations can be inherited?

Answer 5

any mutation that arises in the germ cells.

most mutations occur in the somatic cells, making them noninheritable

Question 6

RNA Structure

Answer 6

long string of nucleotides
single stranded
sugar in each nucleotide is a ribose
U replaces T

Question 7

mRNA

Answer 7

template for protein synthesis.
contains codons- sequence of bases used for transmitting the genetic information needed for protein synthesis
formed from DNA in transcription- DNA bonds are broken so RNA can pair to exposed DNA

Question 8

rRNA

Answer 8

ribosome is the physical structure in the cytoplasm where protein synthesis takes place
forms a little over half of hte ribosome
produced in nucleolus

Question 9

tRNA

Answer 9

works to deliver the activated form of an amino acid that is being synthesized to the ribosomes
carries its own specific amino acid to the ribosomes

Question 10

Transcription

Answer 10

in the cell nucleus. where RNa is synthesized from DNA
complex binds to promoter region (TATA box)
exons: retain protein coding region of the mRNA
introns: between the cells
: permits different proteins to be expressed from a single gene and reduces how much DNA must be contained in their genome

Question 11

Translation

Answer 11

the synthesis of of a protein using the mRNA template

Question 12

Gene Expression Regulation

Answer 12

:degree to which a gene or particular group of genes is active
Transcription factors:
•Induction: an important process by which gene expression is increased
•Gene repression: process by which a regulatory gene acts to reduce or prevent gene expression
•Only about 2% of the genome encodes instructions for the synthesis of proteins; the remainder consists of noncoding regions that are structural or serve to determine where, when, and in what quantity proteins are made. The degree to which a gene or particular group of genes are actively being transcribed is called gene expression. A phenomenon termed induction is an important process by which gene expression is increased

Question 13

Genes controlling protein synthesis

Answer 13

• Structural Genes: specify the amino acid acid sequence of a polypeptide chain
• Regulator Genes: serve a regulatory function without stipulating the structure of protein molecules
• Cells decode mRNAs by reading their nucleotides in groups of three, called codons. Here are some features of codons:
• Most codons specify an amino acid
• Three “stop” codons mark the end of a protein
• One “start” codon, AUG, marks the beginning of a protein and also encodes the amino acid methionine
• Codons in an mRNA are read during translation, beginning with a start codon and continuing until a stop codon is reached. mRNA codons are read from 5’ to 3’ , and they specify the order of amino acids in a protein from N-terminus (methionine) to C-terminus.

Question 14

Barr Body condensation

Answer 14

when 2 x chromosomes cant compete with one another, and when stem cells come out to become the 3 derms (meso, endo, ecto) they can decide which x that they want to use, and the second x becomes the barr body

Question 15

Mitosis

Answer 15

replication of DNA to duplicate somatic cells. typical cell cycle. I - begins to prepare, dna is replicated
P - spindle fibers, chromatides, centrometes form
M - everything lines up in the middle
A - it cleaves
T - new nuclear envelope

Question 16

Meiosis:

Answer 16

germ cells. 4 daughter cells. meiosis 1 and meiosis 2

Question 17

cytogenetics

Answer 17

study of the structure and numeric characteristics of the cells chromosomes

Question 18

karyotyping

Answer 18

the chromosomal appearance

Question 19

cytogenetics

Answer 19

study of the structure and numeric characteristics of the cell’s chromosomes.

Question 20

telomeres

Answer 20

at the end of chromosome, allows DNA sequence to be replicated compltely

Question 21

banding patterns, what are they used for

Answer 21

to describe the position of a gene on a chromosome

Question 22

Pedigree

Answer 22

Mendel. graphic method used to portray family history for inherited traits

Question 23

Recessive trait

Answer 23

one expressed only in a homozygous pairing (AA, aa)

Question 24

Dominant trait

Answer 24

One expressed in either homozygous or heterozygous (AA, Aa, aa)

Question 25

Carrier

Answer 25

heterozygous person, trait does not manifest

Question 26

locus

Answer 26

position of a gene on a chromosome

Question 27

Single-gene trait

Answer 27

when only 1 pair of genes is involved in the transmission of information

Question 28

genotype

Answer 28

sum total of all genetic information in cells

Question 29

phenotype

Answer 29

physical manifestation of genetic information

Question 30

Polygenic inheritance

Answer 30

involves multiple genes at different loci, with each gene exerting a small effect in determining trait. two or more genes. height, skin color, eye color, and weight

Question 31

Multifactorial inheritance

Answer 31

similar to polygenic. the difference is that it also includes environmental effects on the genes

Question 32

Haplotype mapping

Answer 32

human genome project